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* J.W. Steed, D.R. Turner, K. Wallace Core Concepts in Supramolecular Chemistry and Nanochemistry (Wiley, 2007) 315p.
* Brechignac C., Houdy P., Lahmani M. (Eds.) Nanomaterials and Nanochemistry (Springer, 2007) 748p.
* H. Watarai, N. Teramae, T. Sawada Interfacial Nanochemistry: Molecular Science and Engineering at Liquid-Liquid Interfaces (Nanostructure Science and Technology) 2005. 321p.
* Ozin G., Arsenault A.C., Cademartiri L. [http://www.rsc.org/shop/books/2008/9781847558954.asp Nanochemistry: A Chemical Approach to Nanomaterials] 2nd Eds. (Royal Society of Chemistry, 2008) 820p. | 0 | Colloidal Chemistry |
Salts are a natural component in soils and water.
The ions responsible for salination are: Na, K, Ca, Mg and Cl.<br/>
Over long periods of time, as soil minerals weather and release salts, these salts are flushed or leached out of the soil by drainage water in areas with sufficient precipitation. In addition to mineral weathering, salts are also deposited via dust and precipitation. Salts may accumulate in dry regions, leading to naturally saline soils. This is the case, for example, in large parts of Australia.
Human practices can increase the salinity of soils by the addition of salts in irrigation water. Proper irrigation management can prevent salt accumulation by providing adequate drainage water to leach added salts from the soil. Disrupting drainage patterns that provide leaching can also result in salt accumulations. An example of this occurred in Egypt in 1970 when the Aswan High Dam was built. The change in the level of ground water before the construction had enabled soil erosion, which led to high concentration of salts in the water table. After the construction, the continuous high level of the water table led to the salination of arable land. | 1 | Solid-state chemistry |
Titanium undergoes allotropic transformation from its α-phase (hexagonal close-packed (hcp) structure at temperatures less than 882.5 °C) to its β-phase (body centered cubic, bcc) structure at temperatures above 882.3 °C). Alpha-phase titanium products typically exhibit medium to high strength with excellent creep strength, whereas beta-phase titanium products typically exhibit very high strength and low ductility. Foams created under thermal cycling conditions have been shown to exhibit increased porosity due to the density difference between allotropic phases. Davis et al. produced titanium foams with 41% porosity (as compared to 27% porosity through the normal HIP creep mechanism). Increases in overall ductility were also observed in foams created through thermal cycling. In a similar experiment, porosity of 44% was achieved and determined as the maximum achievable porosity under thermal cycling conditions. A later study also utilized exploitation of transformation superplasticity conditions through HIP, but in this case, the titanium powder in the precursor matrix was replaced with titanium wires to create anisotropic pores. The resulting anisotropic pores showed closer correlation with natural bone in that the foams exhibited higher elastic moduli, yield strength and deformation when subjected to longitudinally loaded forces than when loads were applied transversely. | 0 | Colloidal Chemistry |
Friable macro- or micro-scale solid particles can be ground in a ball mill, a planetary ball mill, or other size-reducing mechanism until enough of them are in the nanoscale size range. The resulting powder can be air classified to extract the nanoparticles. | 0 | Colloidal Chemistry |
Odom joined Northwestern Universitys department of chemistry in 2002 and became the department chair in 2018. In 2010, she became the founding chair of the Noble Metal Nanoparticles Gordon Research Conference Between 2016 and 2018, she was associate director of the International Institute for Nanotechnology. Odom has worked on the editorial advisory boards of ACS Nano, Bioconjugate Chemistry, Materials Horizons, Annual Review of Physical Chemistry Natural Sciences, Nano Futures, and Accounts of Chemical Research. Odom became an inaugural associate editor for Royal Society of Chemistrys Chemical Science journal in 2009, a position she held until 2013. She was on the editorial advisory board of Nano Letters beginning in 2010 and became editor-in-chief in 2019. In 2013, she became a founding Executive Editor for ACS Photonics. | 1 | Solid-state chemistry |
From 2008 to 2014, Goodwin was an EPSRC Career Acceleration Fellow and an associate professor in the department of chemistry at University of Oxford. He became a professor of materials chemistry at University of Oxford in 2014 and a university research professor in 2018. He researches inorganic and solid-state chemistry. Goodwin's research has advanced the theoretical and applied studies of disorder and flexibility in materials. His laboratory applied diffraction and modelling techniques to study disordered materials and create new materials. | 1 | Solid-state chemistry |
The processes by which nanoparticles self-assemble are widespread and important. Understanding why and how self-assembly occurs is key in reproducing and optimizing results. Typically, nanoparticles will self-assemble for one or both of two reasons: molecular interactions and external direction. | 0 | Colloidal Chemistry |
Phospholipids, a class of amphiphilic molecules, are the main components of biological membranes. The amphiphilic nature of these molecules defines the way in which they form membranes. They arrange themselves into lipid bilayers, by forming a sheet composed of two layers of lipids. Each layer forms by positioning their lypophilic chains to the same side of the layer. The two layers then stack such that their lyphphilic chains touch on the inside and their polar groups are outside facing the surrounding aqueous media. Thus the inside of the bilayer sheet is a non-polar region sandwiched between the two polar sheets.
Although phospholipids are the principal constituents of biological membranes, there are other constituents, such as cholesterol and glycolipids, which are also included in these structures and give them different physical and biological properties.
Many other amphiphilic compounds, such as pepducins, strongly interact with biological membranes by insertion of the hydrophobic part into the lipid membrane, while exposing the hydrophilic part to the aqueous medium, altering their physical behavior and sometimes disrupting them.
Aβ proteins form antiparallel β sheets which are strongly amphiphilic, and which aggregate to form toxic oxidative Aβ fibrils. Aβ fibrils themselves are composed of amphiphilic 13-mer modular β sandwiches separated by reverse turns. Hydropathic waves optimize the description of the small (40,42 aa) plaque-forming (aggregative) Aβ fragments.
Antimicrobial peptides (AMPs) are another class of amphiphilic molecules, a big data analysis showed that amphipathicity best distinguished between AMPs with and without anti-gram-negative bacteria activities. The higher amphipathicity, the better chances for AMPs possessing antibacterial and antifungal dual activities. | 0 | Colloidal Chemistry |
While bulk MoS in the 2H-phase is known to be an indirect-band gap semiconductor, monolayer MoS has a direct band gap. The layer-dependent optoelectronic properties of MoS have promoted much research in 2-dimensional MoS-based devices. 2D MoS can be produced by exfoliating bulk crystals to produce single-layer to few-layer flakes either through a dry, micromechanical process or through solution processing.
Micromechanical exfoliation, also pragmatically called "Scotch-tape exfoliation", involves using an adhesive material to repeatedly peel apart a layered crystal by overcoming the van der Waals forces. The crystal flakes can then be transferred from the adhesive film to a substrate. This facile method was first used by Konstantin Novoselov and Andre Geim to obtain graphene from graphite crystals. However, it can not be employed for a uniform 1-D layers because of weaker adhesion of MoS to the substrate (either Si, glass or quartz); the aforementioned scheme is good for graphene only. While Scotch tape is generally used as the adhesive tape, PDMS stamps can also satisfactorily cleave MoS if it is important to avoid contaminating the flakes with residual adhesive.
Liquid-phase exfoliation can also be used to produce monolayer to multi-layer MoS in solution. A few methods include lithium intercalation to delaminate the layers and sonication in a high-surface tension solvent. | 1 | Solid-state chemistry |
Chemical corporations that produce PFAS generate approximately US$4 billion in annual profits from the production of this chemical, but it is estimated that they impose much larger costs on taxpayers and the health of the planet's population (i.e. as external costs). Of these costs, remediation efforts fighting PFAS soil and water contamination are the most expensive, followed by the healthcare costs of treating people who develop cancer, thyroid disease, kidney dysfunction, birth defects, and other major medical conditions that have been linked to even low levels of exposure to PFAS, and the costs of monitoring of PFAS pollution in human and other life forms. Such costs to society have been estimated to amount to approximately US$17.5 trillion annually (which would be almost one fifth of the US$96 trillion global GDP in 2021), according to a press release by The International Chemical Secretariat (ChemSec), a Sweden-based NGO that works with industry and policymakers to limit the use of toxic chemicals. | 0 | Colloidal Chemistry |
Note: Some of the following are also partly fresh and/or brackish water.
*Aral Sea
*Aralsor
*Aydar Lake
*Bakhtegan Lake
*Caspian Sea
*Chilika Lake
*Chott el Djerid
*Dabusun Lake
*Dead Sea
*Devil's Lake
*Don Juan Pond
*Garabogazköl
*Goose Lake
*Great Salt Lake
*Grevelingen
*Laguna Colorada
*Laguna Verde
*Lake Abert
*Lake Alakol
*Lake Assal
*Lake Balkhash
*Lake Barlee
*Lake Baskunchak
*Lake Bumbunga
*Lake Enriquillo
*Lake Elton
*Lake Eyre
*Lake Gairdner
*Lake Hillier
*Lake Karum
*Lake Mackay
*Lake Natron
*Lake Paliastomi
*Lake Pontchartrain
*Lake Texoma
*Lake Torrens
*Lake Tuz
*Lake Tyrrell
*Lake Urmia
*Lake Van
*Lake Vanda
*Larnaca Salt Lake
*Little Manitou Lake
*Lough Hyne
*Lonar Lake
*Maharloo Lake
*Mar Chiquita Lake
*Mono Lake
*Nam Lake
*Pangong Lake
*Pulicat Lake
*Qarhan Playa
*Redberry Lake
*Salton Sea
*Sambhar Salt Lake
*Sarygamysh Lake
*Sawa Lake
*Siling Lake
*South Hulsan Lake
*Sutton Salt Lake
*Uvs Lake | 1 | Solid-state chemistry |
While application of inorganic nanoparticles in bionanotechnology shows encouraging advancements from a materials science perspective, the use of such materials in vivo is limited by issues related with toxicity, biodistribution and bioaccumulation. Because metal inorganic nanoparticle systems degrade into their constituent metal atoms, challenges may arise from the interactions of these materials with biosystems, and a considerable amount of the particles may remain in the body after treatment, leading to buildup of metal particles potentially resulting in toxicity.
Recently, however, some studies have shown that certain nanoparticle environmental toxicity effects aren't apparent until nanoparticles undergo transformations to release free metal ions. Under aerobic and anaerobic conditions, it was found that copper, silver, and titanium nanoparticles released low or insignificant levels of metal ions. This is evidence that copper, silver, and titanium NP are slow to release metal ions, and may therefore appear at low levels in the environment. Additionally, nanoshell coatings significantly protect against degradation in the cellular environment and also reduce QDs toxicity by reducing metal ion leakage from the core. | 0 | Colloidal Chemistry |
Tripotassium phosphate, also called tribasic potassium phosphate is a water-soluble salt with the chemical formula KPO(HO) (x = 0, 3, 7, 9). Tripotassium phosphate is basic. | 0 | Colloidal Chemistry |
*Honorary doctorate of the Christian Albrechts University of Kiel (1983) as well as of the University of Ljubljana (1990)
*Award of the Göttingen Academy of Sciences and Humanities (1963)
*Alfred Stock Award of the German Chemical Society (1974)
*Henri Moissan Medal of the Société chimique de France (1986)
*Jozef Stefan Medal of the Jozef Stefan Institute in Ljubljana (1988)
*Otto Hahn Award for Chemistry and Physics (1989) as the first representative of inorganic chemistry
*Lavoisier Medal (along with Derek Barton) of the Société chimique de France (1995)
Furthermore, Hoppe has been a member of several scientific societies and academies as well as of the German National Academy of Sciences Leopoldina in Halle and of the Bavarian Academy of Sciences and Austrian Academy of Sciences. | 1 | Solid-state chemistry |
In materials science, a metal foam is a material or structure consisting of a solid metal (frequently aluminium) with gas-filled pores comprising a large portion of the volume. The pores can be sealed (closed-cell foam) or interconnected (open-cell foam). The defining characteristic of metal foams is a high porosity: typically only 5–25% of the volume is the base metal. The strength of the material is due to the square–cube law.
Metal foams typically retain some physical properties of their base material. Foam made from non-flammable metal remains non-flammable and can generally be recycled as the base material. Its coefficient of thermal expansion is similar while thermal conductivity is likely reduced. | 0 | Colloidal Chemistry |
Nucleation lays the foundation for the nanoparticle synthesis. Initial nuclei play a vital role on the size and shape of the nanoparticles that will ultimately form by acting as templating nuclei for the nanoparticle itself. Long-term stability is also determined by the initial nucleation procedures. Homogeneous nucleation occurs when nuclei form uniformly throughout the parent phase and is less common. Heterogeneous nucleation, however, forms on areas such as container surfaces, impurities, and other defects. Crystals may form simultaneously if nucleation is fast, creating a more monodisperse product. However, slow nucleation rates can cause formation of a polydisperse population of crystals with various sizes. Controlling nucleation allows for the control of size, dispersity, and phase of nanoparticles.
The process of nucleation and growth within nanoparticles can be described by nucleation, Ostwald ripening or the two-step mechanism-autocatalysis model. | 0 | Colloidal Chemistry |
* In 1985, Harry Kroto and co-workers discovered a class of closed-cage carbon molecules known as fullerenes. Buckminsterfullerene (C), which has icosahedral symmetry, becomes JT-active upon addition or removal of one electron. The ordering of energy levels may not be the same as that predicted by Hund's rule.
* Discovery in 1986 by Bednorz and Müller of superconductivity in cuprates with a transition temperature of 35 K, which was higher than the upper limit allowed according to standard BCS theory, was motivated by earlier work by Müller on JT ions in crystals.
*Colossal magnetoresistance, a property of manganese-based perovskites and other materials, has been explained in terms of competition between dynamic Jahn–Teller and double-exchange effects.
*Peierls theorem, which states that a one-dimensional equally spaced chain of ions with one electron per ion is unstable, has common roots with the JT effect. | 1 | Solid-state chemistry |
Hydrogels have been investigated for diverse applications. By modifying the polymer concentration of a hydrogel (or conversely, the water concentration), the Young's modulus, shear modulus, and storage modulus can vary from 10 Pa to 3 MPa, a range of about five orders of magnitude. A similar effect can be seen by altering the crosslinking concentration. This much variability of the mechanical stiffness is why hydrogels are so appealing for biomedical applications, where it is vital for implants to match the mechanical properties of the surrounding tissues. Characterizing the mechanical properties of hydrogels can be difficult especially due to the differences in mechanical behavior that hydrogels have in comparison to other traditional engineering materials. In addition to its rubber elasticity and viscoelasticity, hydrogels have an additional time dependent deformation mechanism which is dependent on fluid flow called poroelasticity. These properties are extremely important to consider while performing mechanical experiments. Some common mechanical testing experiments for hydrogels are tension, compression (confined or unconfined), indentation, shear rheometry or dynamic mechanical analysis.
Hydrogels have two main regimes of mechanical properties: rubber elasticity and viscoelasticity: | 0 | Colloidal Chemistry |
Nickel(III) oxides catalyze the oxidation of benzyl alcohol to benzoic acid using bleach:
Similarly it catalyzes the double oxidation of 3-butenoic acid to fumaric acid: | 1 | Solid-state chemistry |
Hypothyroidism is the most common thyroid abnormality associated with PFAS exposure. PFASs have been shown to decrease thyroid peroxidase, resulting in decreased production and activation of thyroid hormones in vivo. Other proposed mechanisms include alterations in thyroid hormone signaling, metabolism and excretion as well as function of nuclear hormone receptor. | 0 | Colloidal Chemistry |
The measurement of turbidity is a key test of both water clarity and water quality. There are two standard units for reporting turbidity: Formazin Nephelometric Units (FNU) from ISO 7027 and Nephelometric Turbidity Units (NTU) from USEPA Method 180.1. ISO 7027 and FNU is mostly widely used in Europe, whereas NTU is mostly widely used in the U.S. The ISO 7027 provides the method in water quality for the determination of turbidity. It is used to determine the concentration of suspended particles in a sample of water by measuring the incident light scattered at right angles from the sample. The scattered light is captured by a photodiode, which produces an electronic signal that is converted to a turbidity. Open source hardware has been developed following the ISO 7027 method to measure turbidity reliably using an Arduino microcontroller and inexpensive LEDs.
There are several practical ways of checking water quality, the most direct being some measure of attenuation (that is, reduction in strength) of light as it passes through a sample column of water. The alternatively used Jackson Candle method (units: Jackson Turbidity Unit or JTU) is essentially the inverse measure of the length of a column of water needed to completely obscure a candle flame viewed through it. The more water needed (the longer the water column), the clearer the water. Of course water alone produces some attenuation, and any substances dissolved in the water that produce color can attenuate some wavelengths. Modern instruments do not use candles, but this approach of attenuation of a light beam through a column of water should be calibrated and reported in JTUs.
The propensity of particles to scatter a light beam focused on them is now considered a more meaningful measure of turbidity in water. Turbidity measured this way uses an instrument called a nephelometer with the detector set up to the side of the light beam. More light reaches the detector if there are many small particles scattering the source beam than if there are few. The units of turbidity from a calibrated nephelometer can be either NTU or FTU, depending on the standard method used. To some extent, how much light reflects for a given amount of particulates is dependent upon properties of the particles like their shape, color, and reflectivity. For this reason (and the reason that heavier particles settle quickly and do not contribute to a turbidity reading), a correlation between turbidity and total suspended solids (TSS) is somewhat unusual for each location or situation.
Turbidity in lakes, reservoirs, channels, and the ocean can be measured using a Secchi disk. This black and white disk is lowered into the water until it can no longer be seen; the depth (Secchi depth) is then recorded as a measure of the transparency of the water (inversely related to turbidity). The Secchi disk has the advantages of integrating turbidity over depth (where variable turbidity layers are present), being quick and easy to use, and inexpensive. It can provide a rough indication of the depth of the euphotic zone with a 3-fold division of the Secchi depth, however this cannot be used in shallow waters where the disk can still be seen on the bottom.
An additional device, which may help measuring turbidity in shallow waters is the turbidity tube. The turbidity tube condenses water in a graded tube which allows determination of turbidity based on a contrast disk in its bottom, being analogous to the Secchi disk.
Turbidity in air, which causes solar attenuation, is used as a measure of pollution. To model the attenuation of beam irradiance, several turbidity parameters have been introduced, including the Linke turbidity factor (T). | 0 | Colloidal Chemistry |
Although bismuth selenide occurs naturally (as the mineral guanajuatite) at the Santa Catarina Mine in Guanajuato, Mexico as well as some sites in the United States and Europe, such deposits are rare and contain a significant level of sulfur atoms as an impurity. For this reason, most bismuth selenide used in research into potential commercial applications is synthesized. Commercially-produced samples are available for use in research, but the concentration of selenium vacancies is heavily dependent upon growth conditions, and so bismuth selenide used for research is often synthesized in the laboratory.
A stoichiometric mixture of elemental bismuth and selenium, when heated above the melting points of these elements in the absence of air, will become a liquid that freezes to crystalline . Large single crystals of bismuth selenide can be prepared by the Bridgman–Stockbarger method. | 1 | Solid-state chemistry |
Nanolithography is the technique to pattern materials and build devices under nano-scale. Nanolithography is often used together with thin-film-deposition, self-assembly, and self-organization techniques for various nanofabrications purpose. Many practical applications make use of nanolithography, including semiconductor chips in computers. There are many types of nanolithography, which include:
* Photolithography
* Electron-beam lithography
* X-ray lithography
* Extreme ultraviolet lithography
* Light coupling nanolithography
* Scanning probe microscope
* Nanoimprint lithography
* Dip-Pen nanolithography
* Soft lithography
Each nanolithography technique has varying factors of the resolution, time consumption, and cost. There are three basic methods used by nanolithography. One involves using a resist material that acts as a "mask", known as photoresists, to cover and protect the areas of the surface that are intended to be smooth. The uncovered portions can now be etched away, with the protective material acting as a stencil. The second method involves directly carving the desired pattern. Etching may involve using a beam of quantum particles, such as electrons or light, or chemical methods such as oxidation or Self-assembled monolayers. The third method places the desired pattern directly on the surface, producing a final product that is ultimately a few nanometers thicker than the original surface. To visualize the surface to be fabricated, the surface must be visualized by a nano-resolution microscope, which includes the scanning probe microscopy and the atomic force microscope. Both microscopes can also be engaged in processing the final product. | 0 | Colloidal Chemistry |
Defoamers are used in many industrial processes and products: wood pulp, paper, paint, industrial wastewater treatment, food processing, oil drilling, machine tool industry, oils cutting tools, hydraulics, etc. | 0 | Colloidal Chemistry |
Normal saline (NSS, NS or N/S) is the commonly used phrase for a solution of 0.90% w/v of NaCl, 308 mOsm/L or 9.0 g per liter. Less commonly, this solution is referred to as physiological saline or isotonic saline (because it is approximately isotonic to blood serum, which makes it a physiologically normal solution). Although neither of those names is technically accurate because normal saline is not exactly like blood serum, they convey the practical effect usually seen: good fluid balance with minimal hypotonicity or hypertonicity. NS is used frequently in intravenous drips (IVs) for people who cannot take fluids orally and have developed or are in danger of developing dehydration or hypovolemia. NS is also used for aseptic purpose. NS is typically the first fluid used when hypovolemia is severe enough to threaten the adequacy of blood circulation, and has long been believed to be the safest fluid to give quickly in large volumes. However, it is now known that rapid infusion of NS can cause metabolic acidosis.
The solution is 9 grams of sodium chloride (NaCl) dissolved in water, to a total volume of 1000 ml (weight per unit volume). The mass of 1 millilitre of normal saline is 1.0046 grams at 22 °C. The molecular weight of sodium chloride is approximately 58.4 grams per mole, so 58.4 grams of sodium chloride equals 1 mole. Since normal saline contains 9 grams of NaCl, the concentration is 9 grams per litre divided by 58.4 grams per mole, or 0.154 mole per litre. Since NaCl dissociates into two ions – sodium and chloride – 1 molar NaCl is 2 osmolar. Thus, NS contains 154 mEq/L of Na and the same amount of Cl. This points to an osmolarity of 154 + 154 = 308, which is higher (i.e. more solute per litre) than that of blood (approximately 285). However, if the osmotic coefficient (a correction for non-ideal solutions) is taken into account, then the saline solution is much closer to isotonic. The osmotic coefficient of NaCl is about 0.93, which yields an osmolarity of 0.154 × 1000 × 2 × 0.93 = 286.44. Therefore, the osmolarity of normal saline is a close approximation to the osmolarity of blood. | 1 | Solid-state chemistry |
* Antibiotic misuse
* Dishwashing soap
* Foam
* List of cleaning products
* Hand washing
* Palm oil
* Soap bubble
* Soap dish
* Soap dispenser
* Soap plant
* Soap substitute
* Soapwort
* Shampoo
* Shower gel
* Toothpaste
* Soap made from human corpses | 1 | Solid-state chemistry |
Professor T.S. Kê was a recipient of numerous national and international awards such as the Zener Prize in 1989, and Robert Franklin Mehl Award in 1999 (considered to be the highest international award in the field of materials science). | 1 | Solid-state chemistry |
Copper(II) oxide or cupric oxide is an inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being CuO or copper(I) oxide (cuprous oxide). As a mineral, it is known as tenorite. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds. | 1 | Solid-state chemistry |
A standard method for the preparation of N-acylamino acids is the Schotten-Baumann reaction, in which oleoyl chloride (from oleic acid and, e.g. phosphorus trichloride) is added to an aqueous solution of N-methylglycine at pH 10 (kept constant by the addition of sodium hydroxide solution).
Fatty acid-free N-oleoylsarcosine is obtained as an oil. The method is not suitable for industrial surfactant synthesis because of the relatively expensive production of the carboxylic acid chlorides and the expensive disposal of the phosphonic acid obtained as a byproduct.
N-Oleoylsarcosine can be obtained in the reaction of oleic acid, N-methylglycine and its sodium salt at 170 °C for 8 to 10 hours upon elimination of water.
More gentle conditions (120 °C) and shorter reaction times (3.5 hours) can be used when methyl oleate is reacted with sodium N-methylglycinate upon the addition of equimolar amounts of sodium methoxide in methanol. After absorption in water, acidification with concentrated sulfuric acid and extraction with butanone, N-Oleoylsarcosine is obtained in 92.5% yield. | 0 | Colloidal Chemistry |
When employing dissolvable spacers, it is possible to remove the spacer after sintering, which reduces the risk of pore collapse.
In most cases, foams created using space-holders contain bimodal pore distributions with macro-sized pores resulting from the space-holder particles and micro-sized pores located on the pore walls and resulting from incomplete sintering of the powder matrix. As a result, the macropores typically exhibit rough internal surfaces. In some applications, such as for the use of bio-medical implants, this is an advantageous property. Inner porosity (or micro-porosity) has been shown to reduce stiffness; thus, reduce the risk of stress-shielding effects, while also offering improved osseointegration. | 0 | Colloidal Chemistry |
The stability of a nanoparticle is a term often used to describe the preservation of a specific, usually size-dependent, property of the particle. It can refer to e.g.: its size, shape, composition, crystalline structure, surface properties or dispersion within a solution. The interfacial layer of a nanoparticle can aid these types of stabilities in different ways.
The ligands can bind to the different facets of a nanoparticle, the size and type of which will determine the way the ligands will be ordered. The way the ligands are attached to the particle, ordered disordered or somewhere in between, plays a crucial role in the way different particles will interact. This in turn affects the reactivity of the nanoparticle, which is another way to look at the stability of the particle. | 0 | Colloidal Chemistry |
Dynamic electrophoretic mobility is a parameter that determines intensity of electroacoustic phenomena, such as Colloid Vibration Current and Electric Sonic Amplitude in colloids. It is similar to electrophoretic mobility, but at high frequency, on a scale of megahertz. Usual electrophoretic mobility is the low frequency limit of the dynamic electrophoretic mobility. | 0 | Colloidal Chemistry |
In the typical PAC spectrometer, a setup of four 90° and 180° planar arrayed detectors or six octahedral arrayed detectors are placed around the radioactive source sample. The detectors used are scintillation crystals of BaF or NaI. For modern instruments today mainly LaBr:Ce or CeBr are used. Photomultipliers convert the weak flashes of light into electrical signals generated in the scintillator by gamma radiation. In classical instruments these signals are amplified and processed in logical AND/OR circuits in combination with time windows the different detector combinations (for 4 detectors: 12, 13, 14, 21, 23, 24, 31, 32, 34, 41, 42, 43) assigned and counted. Modern digital spectrometers use digitizer cards that directly use the signal and convert it into energy and time values and store them on hard drives. These are then searched by software for coincidences. Whereas in classical instruments, "windows" limiting the respective γ-energies must be set before processing, this is not necessary for the digital PAC during the recording of the measurement. The analysis only takes place in the second step. In the case of probes with complex cascades, this makes it makes it possible to perform a data optimization or to evaluate several cascades in parallel, as well as measuríng different probes simultaneously. The resulting data volumes can be between 60 and 300 GB per measurement. | 1 | Solid-state chemistry |
Initially planning on entering the family fashion and tailor business, he entered Kings College London in 1962, the first member of his family to attend university. Ozin graduated with a first-class honours degree in chemistry from Kings College London in 1965, and obtained his PhD in inorganic chemistry at Oriel College, Oxford in 1967 with Prof. Ian R. Beattie. He then was an Imperial Chemical Industries postdoctoral fellow at the University of Southampton from 1967-1969. In 1969, he began his independent career at the University of Toronto as an Assistant Professor. He was promoted to Associate Professor in 1972, and full Professor in 1977. | 1 | Solid-state chemistry |
Klemm was a member of the Academy of Sciences Leopoldina (Deutsche Akademie der Naturforscher Leopoldina) in Halle, Germany; the Bavarian Academy of Sciences and Humanities (Bayerische Akademie der Wissenschaften) in Munich, Germany;
the Göttingen Academy of Sciences (Akademie der Wissenschaften zu Göttingen) in Göttingen, Germany; and
the Rhine-Westphalian Academy of Sciences in Düsseldorf, Germany.
Klemm was co-editor of Zeitschrift für anorganische und allgemeine Chemie (the journal for inorganic and general chemistry) from 1939 to 1965.
From 1945 onwards, his central tasks were to reestablish teaching and research in Kiel (1947-1951) and in Münster (1951-) and to help reconstruct chemical institutions at the national and international levels.
Wilhelm Klemm was an influential science organizer. He became the second president of the Gesellschaft Deutscher Chemiker (1952-1953), working to foster communication between chemists in different zones of post-war Germany.
In the 1950s and 1960s, he worked to build communication and cohesion between scientists in the GDR and the Federal Republic.
As president of the GDCh he participated in the founding of the Chemical Society of the GDR, formally created on 11 May 1953.
Wilhelm Klemm campaigned for international exchange in the sciences. From 1965 to 1967 he was President of the International Union of Pure and Applied Chemistry (IUPAC).
He was the first German scientist to fill such a high international position after World War II.
In 1966 he became the secretary-treasurer of the recently formed Committee on Data for Science and Technology (CODATA) of the International Council of Scientific Unions (ICSU), whose purpose was to encourage the use of international standards of scientific nomenclature, symbols, constants, and data sets. He served on the committee from 1968 to 1975, also holding the position of vice-president. | 1 | Solid-state chemistry |
Quantum tunnelling falls under the domain of quantum mechanics: the study of what happens at the quantum scale, which classical mechanics cannot explain. To understand the phenomenon, particles attempting to travel across a potential barrier can be compared to a ball trying to roll over a hill. Quantum mechanics and classical mechanics differ in their treatment of this scenario.
Classical mechanics predicts that particles that do not have enough energy to classically surmount a barrier cannot reach the other side. Thus, a ball without sufficient energy to surmount the hill would roll back down. In quantum mechanics, a particle can, with a small probability, tunnel to the other side, thus crossing the barrier. The reason for this difference comes from treating matter as having properties of waves and particles. | 1 | Solid-state chemistry |
As with other metal foams, the properties of titanium foams depend mostly on the properties of the starting material and the relative density of the resultant foam. Thermal properties in foams – such as melting point, specific heat and expansion coefficient – remain constant for both the foams and the metals from which they are composed. However, the mechanical properties of foams are greatly influenced by microstructure, which include the aforementioned properties as well as anisotropy and defects within the foam's structure. | 0 | Colloidal Chemistry |
Occupational exposure to PFASs occurs in numerous industries due to the widespread use of the chemicals in products and as an element of industrial process streams. PFASs are used in more than 200 different ways in industries as diverse as electronics and equipment manufacturing, plastic and rubber production, food and textile production, and building and construction. Occupational exposure to PFASs can occur at fluorochemical facilities that produce them and other manufacturing facilities that use them for industrial processing like the chrome plating industry. Workers who handle PFAS-containing products can also be exposed during their work, such as people who install PFAS-containing carpets and leather furniture with PFAS coatings, professional ski-waxers using PFAS-based waxes, and fire-fighters using PFAS-containing foam and wear flame-resistant protective gear made with PFASs. | 0 | Colloidal Chemistry |
Palierne equation connects the dynamic modulus of emulsions with the dynamic modulus of the two phases, size of the droplets and the interphase surface tension. The equation can also be used for suspensions of viscoelastic solid particles in viscoelastic fluids. The equation is named after French rheologist Jean-François Palierne, who proposed the equation in 1991.
For the dilute emulsions Palierne equation looks like:
where is the dynamic modulus of the emulsion, is the dynamic modulus of the continuous phase (matrix), is the volume fraction of the disperse phase and the is given as
where is the dynamic modulus of the disperse phase, is the surface tension between the phases and is the radius of the droplets.
For the suspension of solid particles the value of is given as
The Palierne equation is usually extended for the finite volume concentrations of the disperse phase as: | 0 | Colloidal Chemistry |
In the unswollen state, hydrogels can be modelled as highly crosslinked chemical gels, in which the system can be described as one continuous polymer network. In this case:
where G is the shear modulus, k is the Boltzmann constant, T is temperature, N is the number of polymer chains per unit volume, ρ is the density, R is the ideal gas constant, and is the (number) average molecular weight between two adjacent cross-linking points. can be calculated from the swell ratio, Q, which is relatively easy to test and measure.
For the swollen state, a perfect gel network can be modeled as:
In a simple uniaxial extension or compression test, the true stress, , and engineering stress, , can be calculated as:
where is the stretch. | 0 | Colloidal Chemistry |
Copper(I) iodide reacts with mercury vapors to form copper tetraiodomercurate:
:4CuI + Hg → CuHgI + 2Cu
This reaction can be used for the detection of mercury since the white (CuI) to brown (CuHgI) color change is dramatic.
Copper(I) iodide is used in the synthesis of Cu(I) clusters such as .
Copper(I) iodide dissolves in acetonitrile, yielding diverse complexes. Upon crystallization, molecular or polymeric compounds can be isolated. Dissolution is also observed when a solution of the appropriate complexing agent in acetone or chloroform is used. For example, thiourea and its derivatives can be used. Solids that crystallize out of those solutions are composed of hybrid inorganic chains. | 1 | Solid-state chemistry |
Alkali metal and alkaline earth soaps are white solids. The most commonly encountered are traditional household soaps, which are the fatty acid salts of sodium (hard soap) and potassium (soft soap). Lithium soap or greases, such as lithium stearate, are insoluble in water and find use in lubricating grease.
Calcium and magnesium soaps are most commonly encountered as soap scum but the pure materials have a variety of uses. Magnesium stearate and calcium stearate are used as excipients, lubricants, release agents, and food additives, with the later use being covered by the generic E numbers of E470b and E470 respectively. | 1 | Solid-state chemistry |
Class A foams were developed in the mid-1980s for fighting wildfires. Class A foams lower the surface tension of the water, which assists in the wetting and saturation of Class A foams with water. It penetrates and extinguishes embers at depth. This aids fire suppression and can prevent re-ignition. Favourable experiences led to its acceptance for fighting other types of class A fires, including structure fires. | 0 | Colloidal Chemistry |
The acoustical property of the speed of sound through a foam is of interest when analyzing failures of hydraulic components. The analysis involves calculating total hydraulic cycles to fatigue failure. The speed of sound in a foam is determined by the mechanical properties of the gas creating the foam: oxygen, nitrogen, or combinations.
Assuming that the speed of sound is based on the liquid's fluid properties leads to errors in calculating fatigue cycles and failure of mechanical hydraulic components. Using acoustical transducers and related instrumentation that set low limits (0–50,000 Hz with roll-off) causes errors. The low roll-off during measurement of actual frequency of acoustic cycles results in miscalculation due to actual hydraulic cycles in the possible ranges of 1–1000 MHz or higher. Instrumentation systems are most revealing when cycle bandwidths exceed the actual measured cycles by a factor of 10 to 100. Associated instrumentation costs also increase by factors of 10 to 100.
Most moving hydro-mechanical components cycle at 0–50 Hz, but entrained gas bubbles resulting in a foamy condition of the associated hydraulic fluid results in actual hydraulic cycles that can exceed 1000 MHz even if the moving mechanical components do not cycle at the higher cycle frequency. | 0 | Colloidal Chemistry |
The three-dimensional shape depends upon how the fivelings are formed, including the environment such as gas pressure and temperature. In the very early work only pentagonal bipyramids were reported. In 1970 Ino tried to model the energetics, but found that these bipyramids were higher in energy than single crystals with a Wulff construction shape. He found a lower energy form where he added {100} facets, what is now commonly called the Ino decahedron. The surface energy of this form and a related icosahedral twin scale as the two-thirds power of the volume, so they can be lower in energy than a single crystal as discussed further below. However, while Ino was able to explain the icosahedral particles, he was not able to explain the decahedral ones. Later Laurence D. Marks proposed a model using both experimental data and a theoretical analysis, which is based upon a modified Wulff construction which includes more surface facets, including Inos {100} as well as re-entrant {111} surfaces at the twin boundaries with the possibility of others such as {110}, while retaining the decahedral point group symmetry. This approach also includes the effect of gas and other environmental factors via how they change the surface energy of different facets. By combining this model with de Wits elasticity, Archibald Howie and Marks were able to rationalize the stability of the decahedral to particles. Other work soon confirmed the shape reported by Marks for annealed particles. This was further confirmed in detailed atomistic calculations a few years later by Charles Cleveland and Uzi Landman who coined the term Marks decahedra for these shapes, this name now being widely used.
The minimum energy or thermodynamic shape for these particles depends upon the relative surface energies of different facets, similar to a single crystal Wulff shape; they are formed by combining segments of a conventional Wulff construction with two additional internal facets to represent the twin boundaries. An overview of codes to calculate these shapes was published in 2021 by Christina Boukouvala et al. Considering just {111} and {100} facets:
* The Ino decahedron occurs when the surface energy of the {100} facets is small, ;
* Common is the Marks decahedron with {100} facets and a re-entrant surface at the twin boundaries for
* With there is no {100} faceting, and the particles have been called nanostars.
* For very low the equilibrium shape is a long rod along the common five-fold axis.
The photograph of an 0.5cm gold fiveling from Miass is a Marks decahedron with , while the sketch of Rose is for . The 75 atom cluster shown above corresponds to the same shape for a small number of atoms. Experimentally, in fcc crystals fivelings with only {111} and {100} facets are common, but many other facets can be present in the Wulff construction leading to more rounded shapes, for instance {113} facets for silicon. It is known that the surface can reconstruct to a different atomic arrangement in the outermost atomic plane, for instance a dimer reconstruction for {100} facets of silicon particles of a hexagonal overlayer on the {100} facets of gold decahedra.
What shape is present depends not just on the surface energy of the different facets, but also upon how the particles grow. The thermodynamic shape is determined by the Wulff construction, which considers the energy of each possible surface facet and yields the lowest energy shape. The original Marks decahedron was based upon a form of Wulff construction that takes into account the twin boundaries. There is a related kinetic Wulff construction where the growth rate of different surfaces is used instead of the energies. This type of growth matters when the formation of a new island on a flat facet limits the growth rate. If the {100} surfaces of Ino grow faster then they will not appear in the final shape, similarly for the re-entrant surfaces at the twin boundaries -- this leads to the pentagonal bipyramids often observed. Alternatively, if the {111} surfaces grow fast and {100} slow the kinetic shape will be a long rod along the common five-fold axis as shown in the figure.
Another different set of shapes can occur when diffusion of atoms to the particles dominates, a growth regime called diffusion controlled growth. In such cases surface curvature can play a major role, for instance leading to spikes originating at the sharp corners of a pentagonal bipyramids, sometimes leading to pointy stars, as shown in the figure. | 1 | Solid-state chemistry |
In the beliefs of the Thai people (especially the southerner), pyrite is known as Khao tok Phra Ruang, Khao khon bat Phra Ruang (ข้าวตอกพระร่วง, ข้าวก้นบาตรพระร่วง) or Phet na tang, Hin na tang (เพชรหน้าทั่ง, หินหน้าทั่ง). It is believed to be a sacred item that has the power to prevent evil, black magic or demons. | 1 | Solid-state chemistry |
The density of states function is defined as the number of electronic states per unit volume, per unit energy, for electron energies near .
The density of states function is important for calculations of effects based on band theory.
In Fermi's Golden Rule, a calculation for the rate of optical absorption, it provides both the number of excitable electrons and the number of final states for an electron. It appears in calculations of electrical conductivity where it provides the number of mobile states, and in computing electron scattering rates where it provides the number of final states after scattering.
For energies inside a band gap, . | 1 | Solid-state chemistry |
Ionic compounds have long had a wide variety of uses and applications. Many minerals are ionic. Humans have processed common salt (sodium chloride) for over 8000 years, using it first as a food seasoning and preservative, and now also in manufacturing, agriculture, water conditioning, for de-icing roads, and many other uses. Many ionic compounds are so widely used in society that they go by common names unrelated to their chemical identity. Examples of this include borax, calomel, milk of magnesia, muriatic acid, oil of vitriol, saltpeter, and slaked lime.
Soluble ionic compounds like salt can easily be dissolved to provide electrolyte solutions. This is a simple way to control the concentration and ionic strength. The concentration of solutes affects many colligative properties, including increasing the osmotic pressure, and causing freezing-point depression and boiling-point elevation. Because the solutes are charged ions they also increase the electrical conductivity of the solution. The increased ionic strength reduces the thickness of the electrical double layer around colloidal particles, and therefore the stability of emulsions and suspensions.
The chemical identity of the ions added is also important in many uses. For example, fluoride containing compounds are dissolved to supply fluoride ions for water fluoridation.
Solid ionic compounds have long been used as paint pigments, and are resistant to organic solvents, but are sensitive to acidity or basicity. Since 1801 pyrotechnicians have described and widely used metal-containing ionic compounds as sources of colour in fireworks. Under intense heat, the electrons in the metal ions or small molecules can be excited. These electrons later return to lower energy states, and release light with a colour spectrum characteristic of the species present.
In chemistry, ionic compounds are often used as precursors for high-temperature solid-state synthesis.
Many metals are geologically most abundant as ionic compounds within ores. To obtain the elemental materials, these ores are processed by smelting or electrolysis, in which redox reactions occur (often with a reducing agent such as carbon) such that the metal ions gain electrons to become neutral atoms. | 1 | Solid-state chemistry |
Asakura and Oosawa described the second case as consisting of two plates in a solution of rod like macromolecules. The rod like macromolecules are described as having a length, , where , the area of the plates. As the length of the rods increases, the concentration of the rods between the plates is decreased as it becomes more difficult for the rods to enter between the plates due to steric hindrances. As a result, the force acting on the plates increases with the length of the rods until it becomes equal to the osmotic pressure. In this context, it is worth mentioning that even the isotropic-nematic transition of lyotropic liquid crystals, as first explained in Onsager's theory, can in itself be considered a special case of depletion forces. | 0 | Colloidal Chemistry |
Sodium perxenate, NaXeO, can be used for the analytic separation of trace amounts of americium from curium. The separation involves the oxidation of Am to Am by sodium perxenate in acidic solution in the presence of La, followed by treatment with calcium fluoride, which forms insoluble fluorides with Cm and La, but retains Am and Pu in solution as soluble fluorides. | 1 | Solid-state chemistry |
Stacy received a B.A. in physics and chemistry magna cum laude at LaSalle College (1977). Stacy would then go on to receive her Ph.D. from Cornell University (1981) with Professor Michell J Sienko. She was a postdoctoral fellow at Northwestern University (1981–1983) with Professor Richard van Duyne and Professor Peter Stair prior to beginning her faculty position in the college of chemistry at the University of California, Berkeley. As a junior faculty member at Berkeley, Stacy was the first recipient of the Prytanean Faculty Award, which is an unrestricted grant awarded to distinguished female faculty members at UC Berkeley.
In the area of service, and as a senior member of the faculty at the University of California, Stacy has been outspoken about her commitment to issues surrounding diversity and equity in the sciences. Stacy has served as co-investigator and principal investigator of the University of California Faculty Family-Friendly Edge, which is a Sloan Foundation research project based at UC Berkeley. In these roles and that of associate vice provost of the faculty at the University of California, Berkeley, Stacy is particularly committed to promoting "data-driven initiatives to increase equity and inclusion in faculty recruitment, advancement, and retention".
In addition to her research in the area of chemistry education at the university level, Stacy has been outspoken on the importance of exposure to chemistry research (and research in the sciences more generally) at the high school level to help promote interest in career pathways in basic research, as a pathway to improve diversity in the field, and as a strategy to enhance student learning outcomes. She has spoken on the importance of high school educators as key to these endeavors:
"I have to come to the defense of my high school colleagues. Nothing is going to change until we respect them as professionals. They have a lot to offer. They have many ideas, but no time. They are in contact with students every hour of the day. There are no longer in-service days or professional days in many states. High school teachers know what they would like to do, but they have no time to do it. Yet we treat them as if we need to go and help them. In fact, I think we have much to learn from them. Until we come to the table with our high school colleagues, acknowledging them as the high-level professionals that they are, things are not going to change."
Stacy is also the author of the book Living by Chemistry, a research-based curriculum for students at the high school level. | 1 | Solid-state chemistry |
The Amersfoort-born Coppens received his B.S. and Ph.D. degrees from the University of Amsterdam in 1954 and 1960, where he was supervised by Carolina MacGillavry. In 1968, following appointments at the Weizmann Institute and Brookhaven National Laboratory, he was appointed in the chemistry department at the State University of New York at Buffalo. He was a SUNY Distinguished Professor and holder of the Henry M. Woodburn Chair of Chemistry. Among the many 3-dimensional structures Coppens characterized is the nitroprusside ion. | 1 | Solid-state chemistry |
Wests book Solid State Chemistry and its applications' and its condensed version "Basic Solid State Chemistry" are well-regarded texts in the field and a recent updated version of the former as a student edition was published in 2014.
West was the founder of the RSC journal Journal of Materials Chemistry in 1991 and of the "Materials Chemistry" conference series in the UK, organising the first in Aberdeen in 1991. | 1 | Solid-state chemistry |
As the alveoli increase in size, the surfactant becomes more spread out over the surface of the liquid. This increases surface tension effectively slowing the rate of expansion of the alveoli. This also helps all alveoli in the lungs expand at the same rate, as one that expands more quickly will experience a large rise in surface tension slowing its rate of expansion. It also means the rate of shrinking is more regular as if one reduces in size more quickly the surface tension will reduce more, so other alveoli can contract more easily than it can. Surfactant reduces surface tension more readily when the alveoli are smaller because the surfactant is more concentrated. | 0 | Colloidal Chemistry |
The selection of the space-holder is one of the most crucial steps because it defines many of the properties of the resulting foam, including cell shape, cell size and macroporosity. The space-holder should be inert and represent the size and shape of the desired pores. The porosity may be adjusted anywhere between 50 and 85% without the filler material becoming a part of the resultant foam. It is also important to select a spacer that has limited or no solubility in titanium, as this incorporation will affect the mechanical properties of the resulting foam. | 0 | Colloidal Chemistry |
Arnold Guloy is an American chemist who is Professor of Chemistry at the University of Houston. He is an expert in the area Zintl phases chemistry, crystal growth, materials discovery, and superconductivity. | 1 | Solid-state chemistry |
Tailorability is one of the biggest advantages of these materials. The matrix material can be selected from almost any metal, polymer, or ceramic. Microballoons are available in a variety of sizes and materials, including glass microspheres, cenospheres, carbon, and polymers. The most widely used and studied foams are glass microspheres (in epoxy or polymers), and cenospheres or ceramics (in aluminium). One can change the volume fraction of microballoons or use microballoons of different effective density, the latter depending on the average ratio between the inner and outer radii of the microballoons.
A manufacturing method for low density syntactic foams is based on the principle of buoyancy. | 0 | Colloidal Chemistry |
The β-InS polymorph, in powdered form, can irritate eyes, skin and respiratory organs. It is toxic if swallowed, but can be handled safely under conventional laboratory conditions. It should be handled with gloves, and care should be taken to keep from inhaling the compound, and to keep it from contact with the eyes. | 1 | Solid-state chemistry |
A colloidal crystal is an ordered array of colloidal particles and fine grained materials analogous to a standard crystal whose repeating subunits are atoms or molecules. A natural example of this phenomenon can be found in the gem opal, where spheres of silica assume a close-packed locally periodic structure under moderate compression. Bulk properties of a colloidal crystal depend on composition, particle size, packing arrangement, and degree of regularity. Applications include photonics, materials processing, and the study of self-assembly and phase transitions. | 0 | Colloidal Chemistry |
In organic synthesis, PPTS is used as a weakly acidic catalyst, providing an organic soluble source of pyridinium (CHNH) ions. For example, PPTS is used to deprotect silyl ethers or tetrahydropyranyl ethers when a substrate is unstable to stronger acid catalysts. It is also a commonly used catalyst for the preparation of acetals and ketals from aldehydes and ketones. | 1 | Solid-state chemistry |
Salt-concrete was used for the first time in 1984 in the potash mine in Rocanville in Canada. A salt-concrete seal was also installed in the Asse II mine in Lower Saxony in 1995. | 1 | Solid-state chemistry |
An adduct ion is formed from a precursor ion and contains all of the constituent atoms of that ion as well as additional atoms or molecules. Adduct ions are often formed in a mass spectrometer ion source. | 1 | Solid-state chemistry |
While the formation of other caliches is relatively well understood, the origin of Chilean caliche is not clearly known. One possibility is that the deposits were formed when a prehistoric inland sea evaporated. Another theory is that it was deposited due to weathering of the Andes.
One of the world's largest deposits of calcrete is in the Makgadikgadi Pans in Botswana, where surface calcretes occur at the location of a now-desiccated prehistoric lake.
Highly indurated (hardened) caliche is known as calcrete, and it gives rise to characteristic landforms in arid environments. Calcrete is found throughout the geologic record, forming a record of past climate. Examples include Mississippian calcretes in South Wales and Pliocene to Pleistocene caprock of the Llano Estacado of Texas, US, and Mormon Mesa, Nevada, US.
Caliches can store significant amounts of carbon, making them of significance to the overall global carbon cycle.
In Jurassic geological settings, the caliche is often indicator of warm climate with well marked wet-dry seasonality that could indicate seasonal monsoons. | 1 | Solid-state chemistry |
A boilery or boiling house is a place of boiling, much as a bakery is a place of baking. Boilery can also mean the process and equipment for boiling. Although they are now generally confined to factories, and usually boil industrial products rather than food, historically they were more common in daily life. Boileries are typically for boiling large quantities of fluid.
In the 17th to 19th centuries, boileries were used to convert sugarcane juice into raw sugar. These boileries were usually sturdy places, built from stone, and contained several copper kettles, each with a furnace beneath it., Sugarcane juice was treated with lime in large clarifying vats, before it was heated in copper kettles over individual furnaces. Due to their importance, many Western sugar plantations had their own boileries on site.
Soap would also be made in a boiling house.
Another use for a boilery is to make salt through the evaporation of brine water. | 1 | Solid-state chemistry |
*Thomas, A. W. (1913). A further effort to prepare a colorless biuret reagent. Biochemical Bulletin (New York), 2, 556–8.
*Thomas, A. W. (1914). A review of methods for the isolation and identification of the organic constituents of soils. Biochemical Bulletin (New York), 3, 210–21.
*Thomas, A. W. (1914). The phosphorus content of starch. Biochemical Bulletin (New York), 3, 403–6.
*Thomas, A. W. (1915). The chemical constitution of starch. A review. Biochemical Bulletin (New York), 4, 379–97.
*Sherman, H. C., & Thomas, A. W. (1915). Studies on amylases. VIII. The influence of certain acids and salts upon the activity of malt amylase. Journal of the American Chemical Society, 37, 623–43.
*Wilson, J. A., & Thomas, A. W., et al. (1917). Theories of leather formation. Discussion. Journal of the American Leather Chemists Association, 12, 450–61.
*Thomas, A. W. (1917). A noteworthy effect of bromides upon the action of malt amylase. Journal of the American Chemical Society, 39, 1501–3.
*Thomas, A. W., & Baldwin, M. E. (1918). The acidity of chrome liquors. Journal of the American Leather Chemists Association, 13, 192–203.
*Thomas, A. W., & Baldwin, M. E. (1918). The action of neutral salts upon chrome liquors. Journal of the American Leather Chemists Association, 13, 248–55.
*Thomas, A. W. (1918). Science, 47, 10–4.
*Thomas, A. W., & Garard, I. D. (1918). Fallacy of determining electrical charge of colloids by capillarity. Journal of the American Chemical Society, 40, 101–6.
*Sherman, H. C., Thomas, A. W., & Baldwin, M. E. (1919). Influence of hydrogen-ion concentration upon enzymatic activity of three typical amylases. Journal of the American Chemical Society, 41, 231–5.
*Thomas, A. W., & Baldwin, M. E. (1919). Contrasting effects of chlorides and sulfates on the hydrogen-ion concentration of acid solutions. Journal of the American Chemical Society, 41, 1981–90.
*Thomas, A. W., & Foster, S. B. (May 1, 1920). Titration of chrome liquors by the conductance method. Hide and Leather, 97–9.
*Thomas, A. W. (May 1, 1920). Determination of sulfuric acid in leather. Hide and Leather, 101.
*Thomas, A. W. (1920). A review of the literature of emulsions. Journal of Industrial and Engineering Chemistry, 12, 177–81.
*Thomas, A. W. (1920). Tabulation of hydrogen and hydroxyl ion concentrations of some acids and bases. Journal of the American Leather Chemists Association, 15, 133–46.
*Thomas, A. W., Baldwin, M. E., & Kelly, M. W. (1920). Time factor in the adsorption of the constituents of chrome liquor by hide substance. Journal of the American Leather Chemists Association, 15, 147–56.
*Thomas, A. W. (1920). Emulsions: theory and practice. Journal of the American Leather Chemists Association, 15, 186–201.
*Thomas, A. W. (1920). Estimation of the tryptic activity of bating materials. Journal of the American Leather Chemists Association, 15, 221–8.
*Thomas, A. W., & Frieden, A. (1920). The determination of hydrochloric acid and neutral chlorides in leather. Journal of Industrial and Engineering Chemistry, 12, 1186–8.
*Thomas, A. W., & Kelly, M. W. (1920). The time factor in the adsorption of chromic sulfate by hide substance. Journal of the American Leather Chemists Association, 15, 487-95 (1920)
*Thomas, A. W. (1920). Determination of sulfuric acid in leather. Journal of the American Leather Chemists Association, 15, 504-10 (1920)
*Thomas, A. W., & Foster, S. B. (1920). Titration of chrome liquors by the conductance method. Journal of the American Leather Chemists Association, 15, 510–6.
*Thomas, A. W. (1920). Order of diffusion of tanning extracts through gelatin jelly and their relation to the results obtained by Wilson and Kern. Journal of the American Leather Chemists Association, 15, 593–5.
*Thomas, A. W., & Kelly, M. W. (1920). Rapid estimation of chromium in chrome liquor by use of the immersion refractometer. Journal of the American Leather Chemists Association, 15, 665–8.
*Thomas, A. W., & Kelly, M. W. (1921). Effect of concentration of chrome liquor upon the adsorption of its constituents by hide substance. Journal of Industrial and Engineering Chemistry, 13, 65–7.
*Quisumbing, F. A., & Thomas, A. W. (1921). Conditions affecting the quantitative determination of reducing sugars by Fehling solution. Elimination of certain errors involved in current methods. Journal of the American Chemical Society, 43, 1503–26.
*Thomas, A. W., & Foster, S. B. (1921). The acid titration of chrome liquors. Journal of the American Leather Chemists Association, 16, 61–3.
*Thomas, A. W. (1922). Research in leather manufacture. Mechanical Engineering, 44, 116.
*A tiny tannery. (January 1922). Scientific American 126, 43. - Photograph and article of Arthur W. Thomas laboratory tannery, "the worlds smallest complete tannery".
*Thomas, A. W. (February 1922). Increased efficiency of leather manufacture is possible through research in fundamentals. Chemical Age. -- Address before the Research Conference at the 42nd annual meeting of the American Society of Mechanical Engineers, New York, December 8, 1921.
*Thomas, A. W., & Kelly, M. W. (1922). The isoelectric point of collagen. Journal of the American Chemical Society, 44, 195–201.
*Thomas, A. W., & Foster, S. B. (1922). The influence of sodium chloride, sodium sulfate, and sucrose on the combination of chromic ion with hide substance. Journal of Industrial and Engineering Chemistry, 14, 132–3.
*Thomas, A. W., & Foster, S. B. (1922). Colloid content of vegetable tanning extracts. Journal of Industrial and Engineering Chemistry, 14, 191–5.
*Thomas, A. W., & Kelly, M. W. (1922). Time and concentration factors in the combination of tannin with hide substance. I. Gambier. II. Quebracho. Journal of Industrial and Engineering Chemistry, 14, 292–4.
*Thomas, A. W., & Kelly, M. W. (1922). Studies in chrome tanning. Equilibria between tetrachrome collagen and chrome liquors. The formation of octachrome collagen. Journal of Industrial and Engineering Chemistry, 14, 621–3.
*Thomas, A. W. (1922). Vegetable tanning. Journal of Industrial and Engineering Chemistry, 14, 829–31.
*Thomas, A. W. (1923). The adsorption of chrome from chrome liquors by hide substance and negative adsorption. Journal of the American Leather Chemists Association, 18, 423–30.
*Thomas, A. W., & Foster, S. B. (1923). The electrical charge of vegetable tannin particles. Industrial and Engineering Chemistry, 15, 707-8.
*Thomas, A. W., & Frieden, A. (1923). The gelatin-tannin reaction. Industrial and Engineering Chemistry, 15, 839–41.
*Thomas, A. W., & Kelly, M. W. (1923). The concentration factor in the combination of tannin with hide substance. Industrial and Engineering Chemistry, 15, 928.
*Thomas, A. W., & Kelly, M. W. (1923). The influence of hydrogen-ion concentration in the fixation of vegetable tannins by hide substance. Industrial and Engineering Chemistry, 15, 1148–53.
*Thomas, A. W., & Yu, C. (1923). Determination of the mixture of arachidic and lignoceric acids in peanut oil by means of magnesium soaps. Journal of the American Chemical Society, 45, 113–28.
*Thomas, A. W., & Yu, C. (1923). New qualitative tests for rape and tung oils. Journal of the American Chemical Society, 45, 129–30.
*Thomas, A. W., & Seymour-Jones, F. L. (1923). Hydrolysis of collagen by trypsin. Journal of the American Chemical Society, 45, 1515–22.
*Thomas, A. W., & Kelly, M. W. (1923). The influence of neutral salts upon the fixation of tannin by hide substance. Industrial and Engineering Chemistry, 15, 1262–3.
*Thomas, A. W., & Frieden, A. (1923). Ferric salt as the "solution link" in the stability of ferric oxide hydrosol. Journal of the American Chemical Society, 45, 2522–32.
*Thomas, A. W., & Johnson, L. (1923). The mechanism of the mutual precipitation of certain hydrosols. Journal of the American Chemical Society, 45, 2532–41.
*Thomas, A. W., & Kelly, M. W. (1924). Differences in kind or degree of tannin fixation. Industrial and Engineering Chemistry, 16, 31–2.
*Thomas, A. W., & Seymour-Jones, F. L. (1924). Action of trypsin upon diverse leathers. Industrial and Engineering Chemistry, 16, 157–9.
*Thomas, A. W., & Kelly, M. W. (1924). Tannic acid tannage. Industrial and Engineering Chemistry, 16, 800–3.
*Thomas, A. W., & Kelly, M. W. (1924). Quinone tannage. Industrial and Engineering Chemistry, 16, 925–6.
*Sherman, H. C., Thomas, A. W., & Caldwell, M. I. (1924). Isoelectric point of malt amylase. Journal of the American Chemical Society, 46, 1711–6.
*Thomas, A. W., & Kelly, M. W. (1925). Vegetable tanning. Industrial and Engineering Chemistry, 17, 41–3.
*Thomas, A. W., & Norris, E. R. (1925). "Irregular series" in the precipitation of albumin. Journal of the American Chemical Society, 47, 501–13.
*Thomas, A. W. (1925). The modern trend in colloid chemistry. Journal of Chemical Education, 2, 323–40.
*Thomas, A. W., & Kelly, M. W. (1925). Thermolability of collagen. Journal of the American Chemical Society, 47, 833–6.
*Thomas, A. W., & Foster, S. B. (1925). Destructive and preservative effect of neutral salts upon hide substance. Industrial and Engineering Chemistry, 17, 1162–4.
*Thomas, A. W., & Foster, S. B. (1925). Action of ultra-violet light on hide protein. Journal of the American Leather Chemists Association, 20, 490–4.
*Thomas, A. W., & Kelly, M. W. (1926). Ultrafiltration of vegetable tanning solutions. Industrial and Engineering Chemistry, 18, 136–8.
*Thomas, A. W., Kelly, M. W., & Foster, S. B. (19236). Aldehyde tannage. Journal of the American Leather Chemists Association, 21, 57–76.
*Thomas, A. W. (1926). Sulfur tannage. Industrial and Engineering Chemistry, 18, 259–61.
*Thomas, A. W., & Foster, S. B. (1926). Behavior of deaminized collagen. Further evidence in favor of the chemical nature of tanning. Journal of the American Chemical Society, 48, 489–501.
*Thomas, A. W., & Kelly, M. W. (1926). Further studies of quinone tannage. Industrial and Engineering Chemistry, 18, 383–5.
*Thomas, A. W., & Mattikow, M. (1926). Method for the direct identification of rapeseed oil by isolation of erucic acid. Journal of the American Chemical Society, 48, 968–81.
*Thomas, A. W., & Kelly, M. W. (1926). Does chromium combine with the basic or acidic groups of hide protein? Journal of the American Chemical Society, 48, 1312-9 (1926)
*Thomas, A. W., & Kelly, M. W. (1926). Nature of vegetable tannage. Industrial and Engineering Chemistry, 18, 625–6.
*Thomas, A. W. (1926). Chemical nature of vegetable tanning. Journal of the American Leather Chemists Association, 21, 487–516.
*Thomas, A. W., & Le Compte, T. R. (1926). The so-called adsorption of ferric oxide hydrosol by charcoal. Fourth Colloid Symposium 1926, 328-54 (Chem. Catalog Co.).
*Thomas, A. W. (1927). Emulsions. Journal of the American Leather Chemists Association, 22, 171–211.
*Thomas, A. W., & Wilson, J. A. (1927). Tannins and vegetable tanning materials. International Critical Tables, 2, 239.
*Thomas, A. W., & Kelly, M. W. (1927). Destructive and preservative effects of neutral salts upon hide substance. II. Industrial and Engineering Chemistry, 19, 477–80.
*Thomas, A. W., & Murray, H. A., Jr. (1928). Gum arabic. Journal of Physical Chemistry, 32, 676–97.
*Thomas, A. W., & Kelly, M. W. (1928). Fixation of aluminum by hide substance. Industrial and Engineering Chemistry, 20, 628–32.
*Thomas, A. W., & Kelly, M. W. (1928). Fixation of iron by hide substance. Industrial and Engineering Chemistry, 20, 632–4.
*Thomas, A. W., & Mayer, C. W. (1928). Estimation of the acid-combining capacity of a protein by means of the interferometer. Proceedings of the Society for Experimental Biology and Medicine, 25, 667–9.
*Field, A. M, & Thomas, A. W. (1928). The grading of collodion membranes by means of ethylene glycol. Proceedings of the Society for Experimental Biology and Medicine, 25, 679.
*Thomas, A. W., & Kelly, M. W. (1929). Temperature factor in vegetable tanning fixation. Journal of the American Leather Chemists Association, 24, 282.
*Thomas, A. W., & Kelly, M. W. (1929). Hydrolysis of hide powder in saturated sodium chloride solutions at various pH values. Journal of the American Leather Chemists Association, 24, 280–2.
*Thomas, A. W., & Kelly, M. W. (1929). Influence of acids upon the fixation of wattle tannin by hide powder. Industrial and Engineering Chemistry, 21, 697–8.
*Thomas, A. W., & Kelly, M. W. (1929). Syntan tannage. Industrial and Engineering Chemistry, 21, 698–701.
*Thomas, A. W., & Kelly, M. W. (1929). Effect of pretreatment upon hydrolysis of hide powder by saturated calcium hydroxide solutions. Industrial and Engineering Chemistry, 21, 701–2.
*Thomas, A. W., & Hamburger, E. R. (1930). Ferric oxybromide hydrosols. Journal of the American Chemical Society, 52, 456–63.
*Thomas, A. W., & Whitehead, T. H. (1930). Effect of sulfate and chloride ion on solutions of aluminum salts. Journal of the American Leather Chemists Association, 25, 127-33 (1930).
*Thomas, A. W. (1931). Scientific accomplishments of the medalist. [Nichols Medal award to John Arthur Wilson]. Industrial and Engineering Chemistry, 23, 435–6.
*Thomas, A. W., & Whitehead, T. H. (1931). Ion interchanges in aluminum oxychloride hydrosols. Journal of Physical Chemistry, 35, 27–47.
*Thomas, A. W., & Tai, A. P. (1932). The nature of "aluminum oxide" hydrosols. Journal of the American Chemical Society, 54, 841–55.
*Thomas, A. W. (1933). New conception of certain colloidal oxides. Journal of the American Leather Chemists Association, 28, 2-24.
*Thomas, A. W., & Bailey, M. I. (1933). Gelation of frozen egg magma. Industrial and Engineering Chemistry, 25, 669–74.
*Thomas, A. W. (1934). Leather. Annual Survey of American Chemistry [1933], 8, 294–96.
*Thomas, A. W. (1934). Summary of the isoelectric point of proteins. Journal of the American Leather Chemists Association, 29, 3–16, 52.
*Thomas, A. W., & Mattikow, M. (February 13, 1934) [http://www.google.com/patents?id=n31JAAAAEBAJ Vegetable jelly composition]. U.S. 1,946,649.
*Thomas, A. W., & Thomson, J. C. (934). Preparation of pure eleostearic acid from Chinese wood oil. Journal of the American Chemical Society, 56, 898.
*Thomas, A. W., & Wicklen, F. C. v. (1934). The nature of chromium oxychloride hydrosols. Journal of the American Chemical Society, 56, 794–8.
*Thomas, A. W., & Van Hauwaert, M. A. (1934). Precise method for determining ammoniacal nitrogen in eggs. Industrial and Engineering Chemistry. Analytical Edition, 6, 338–42.
*Thomas, A. W. (1934). Colloid Chemistry. New York: McGraw-Hill.
*Thomas, A. W., & Vartanian, R. D. (1935). The action of acids on hydrous alumina. Journal of the American Chemical Society, 57, 4–7.
*Thomas, A. W. (1935). Solutions of basic salts of aluminum. Paper Trade Journal, 100, No. 9, 36–9.
*Pennington, M. E., & Thomas, A. W. (April 2, 1935). [http://www.google.com/patents?id=0rR4AAAAEBAJ Treating egg material after separation from the shells]. U.S. 1,996,171.
*Thurman, B. H., Thomas, A. W., & Mattikow, M. (March 20, 1935). Coated fabrics and paper; soaps. Brit. 425,986.
*Thomas, A. W., & Kremer, C. B. (1935). Hydrous thoria hydrosols considered as polynuclear basic thorium complexes. Journal of the American Chemical Society, 57, 1821–4.
*Thomas, A. W., & Owens, H. S. (1935). Basic zirconium chloride hydrosols. Journal of the American Chemical Society, 57, 1825–8.
*Thomas, A. W., & Owens, H. S. (1935). The formation of zirconate hydrosols and their disintegration by certain neutral salts. Journal of the American Chemical Society, 57, 2131–5.
*Thomas, A. W., & Kremer, C. B. (1935). Reactions of organic anions with basic thorium chloride hydrosols. Reversal of charge with salts of the hydroxy acids and with nitric acid. Journal of the American Chemical Society, 57, 2538–41.
*Thurman, B. H., Thomas, A. W., & Mattikow, M. (May 5, 1936). [http://www.google.com/patents?id=0bpiAAAAEBAJ Oilproofing paper]. U.S. 2,039,753.
*Thomas, A. W. (1936). Chemical Changes in Matter. New York: Columbia Univ. Press.
*Thomas, A. W., & Miller, H. S. (1936). Basic beryllium and complex beryllate hydrosols: an additional contribution to the concept of polyolated and polyoxolated structures. Journal of the American Chemical Society, 58, 2526–33.
*Thomas, A. W., & Cohen, B. (1937). Catalytic decomposition of hydrogen peroxide by aluminum oxyiodide hyrosols. Journal of the American Chemical Society, 59, 268–72.
*Perkins, B. H., & Thomas, A. W. Olation of basic chromic, aluminum and ferric chloride solutions. Stiasny Festschr 307–31.
*Clay, J. P., & Thomas, A. W. (1938). Catalytic effect of anions upon rate of solution of hydrous alumina by acids. Journal of the American Chemical Society, 60, 2384–90.
*Thomas, A. W., & Cohen, B. (1939). Nature of aluminum oxyiodide hydrosols as revealed by their action on hydrogen peroxide. Journal of the American Chemical Society, 61, 401–33.
*Thomas, A. W., & Stewart, W. G. (1939). Nature of titanium dioxide hydrosols. Kolloid-Zeitschrift, 86, 279–88.
*Thomas, A. W. (1941). Quick review of chemical methods for determining vitamins. Food Industries 13, No. 6, 63–4.
*Greenstein, L. M., & Thomas, A. W. (1942). The viscosity of certain "ferric oxide" hydrosols. Journal of Chemical Physics, 10, 229–40.
*Bailey, M. I., & Thomas, A. W. (1942). Thiamine and riboflavin contents of citrus fruits. Journal of Nutrition, 24, 85–92.
*Thomas, A. W. (1942). John Arthur Wilson - obituary. Journal of the American Leather Chemists Association, 37, 525–30.
*Fitt, T. C., Thomas, A. W., & Taggart, A. F. (1943). The nature of dispersed mineral in flotation pulps. American Institute of Mining and Metallurgical Engineers, Tech. Pub. No. 1575, 7 pp.
*Little, R. W., Thomas, A. W., & Sherman, H. C. (1943). Spectrophotometric studies on the storage of vitamin A in the body. Journal of Biological Chemistry, 148, 441–3.
*Thomas, A. W., et al. (1944). Leo Hendrik Baekeland. Science 100, 23–4.
*Marion, S. P., & Thomas, A. W. (1946). Effect of diverse anions on the pH of maximum precipitation of aluminum hydroxide." Journal of Colloid Science, 1, 221–34.
*Houk, A. E. H., Thomas, A. W., & Sherman, H. C. (1946). Some interrelationships of dietary iron, copper, and cobalt in metabolism. Journal of Nutrition, 31, 609–20.
*Graham, R. P., & Thomas, A. W. (1947). The reactivity of hydrous alumina towards acids. Journal of the American Chemical Society, 69, 816–21.
*Carroll, B., & Thomas, A. W. (1949). Spectral changes of dyes in colloidal solutions of hydrous oxides. Journal of Chemical Physics, 17, 1336.
*Thomas, A. W., Rakowitz, D., & Rosoff, M. (December 31, 1954). Studies of the chemistry, formation and structure of certain aluminum soaps. Final Summary Report to Army Chemical Center, Maryland. Contract No. DA-18-108-CML-3960, Project No. 4-09-04-001. 203 pages.
*Kerr, P. F., Thomas, A. W., & Langer, A. M. (1963). The nature and synthesis of ferrimolybdite. American Mineralogist, 48, 14–32. | 0 | Colloidal Chemistry |
PFASs are commonly used in Class B firefighting foams due to their hydrophobic and lipophobic properties, as well as the stability of the chemicals when exposed to high heat.
Research into occupational exposure for firefighters is emergent, though frequently limited by underpowered study designs. A 2011 cross-sectional analysis of the C8 Health Studies found higher levels of PFHxS in firefighters compared to the sample group of the region, with other PFASs at elevated levels, without reaching statistical significance. A 2014 study in Finland studying eight firefighters over three training sessions observed select PFASs (PFHxS and PFNA) increase in blood samples following each training event. Due to this small sample size, a test of significance was not conducted. A 2015 cross-sectional study conducted in Australia found that PFOS and PFHxS accumulation was positively associated with years of occupational AFFF exposure through firefighting.
Due to their use in training and testing, recent studies indicate occupational risk for military members and firefighters, as higher levels of PFASs in exposure were indicated in military members and firefighters when compared to the general population. PFAS exposure is prevalent among firefighters not only due to its use in emergencies, but also because it is used in personal protective equipment. In support of these findings, states like Washington and Colorado have moved to restrict and penalize the use of Class B firefighting foam for firefighter training and testing. | 0 | Colloidal Chemistry |
Coatings and thin films made from nanoparticles are being used in various applications including displays, sensors, medical devices, energy storages and energy harvesting. Examples include
* Using graphene oxide for applications in electronics
* Using nanoparticles of metal oxides, carbon nanotubes and quantum dots in photovoltaics, displays and sensors
* Using polymers and nanocomposites in nanolithographic patterning
* Using nanoparticles to scatter light, creating new optical effects | 0 | Colloidal Chemistry |
A foam is said to be regular when the structure is ordered. Direct molding is one technology that produces regular foams with open pores. Metal foams can also be produced by additive processes such as selective laser melting (SLM).
Plates can be used as casting cores. The shape is customized for each application. This manufacturing method allows for "perfect" foam, so-called because it satisfies Plateau's laws and has conducting pores of the shape of a truncated octahedron Kelvin cell (body-centered cubic structure). | 0 | Colloidal Chemistry |
Tripotassium phosphate can be used in foods as a buffering agent, emulsifying agent, and for nutrient fortification. It can serve as a sodium-free substitute for trisodium phosphate. The ingredient is most common in dry cereals but is also found in meat, sauces, and cheeses. | 0 | Colloidal Chemistry |
YBCO crystallizes in a defect perovskite structure consisting of layers. The boundary of each layer is defined by planes of square planar CuO units sharing 4 vertices. The planes can sometimes be slightly puckered. Perpendicular to these CuO planes are CuO ribbons sharing 2 vertices. The yttrium atoms are found between the CuO planes, while the barium atoms are found between the CuO ribbons and the CuO planes. This structural feature is illustrated in the figure to the right.
Although YBaCuO is a well-defined chemical compound with a specific structure and stoichiometry, materials with fewer than seven oxygen atoms per formula unit are non-stoichiometric compounds. The structure of these materials depends on the oxygen content. This non-stoichiometry is denoted by the x in the chemical formula YBaCuO. When x = 1, the O(1) sites in the Cu(1) layer (as labelled in the unit cell) are vacant and the structure is tetragonal. The tetragonal form of YBCO is insulating and does not superconduct. Increasing the oxygen content slightly causes more of the O(1) sites to become occupied. For x < 0.65, Cu-O chains along the b axis of the crystal are formed. Elongation of the b axis changes the structure to orthorhombic, with lattice parameters of a = 3.82, b = 3.89, and c = 11.68 Å. Optimum superconducting properties occur when x ~ 0.07, i.e., almost all of the O(1) sites are occupied, with few vacancies.
In experiments where other elements are substituted on the Cu and Ba sites, evidence has shown that conduction occurs in the Cu(2)O planes while the Cu(1)O(1) chains act as charge reservoirs, which provide carriers to the CuO planes. However, this model fails to address superconductivity in the homologue Pr123 (praseodymium instead of yttrium). This (conduction in the copper planes) confines conductivity to the a-b planes and a large anisotropy in transport properties is observed. Along the c axis, normal conductivity is 10 times smaller than in the a-b plane. For other cuprates in the same general class, the anisotropy is even greater and inter-plane transport is highly restricted.
Furthermore, the superconducting length scales show similar anisotropy, in both penetration depth (λ ≈ 150 nm, λ ≈ 800 nm) and coherence length, (ξ ≈ 2 nm, ξ ≈ 0.4 nm). Although the coherence length in the a-b plane is 5 times greater than that along the c axis it is quite small compared to classic superconductors such as niobium (where ξ ≈ 40 nm). This modest coherence length means that the superconducting state is more susceptible to local disruptions from interfaces or defects on the order of a single unit cell, such as the boundary between twinned crystal domains. This sensitivity to small defects complicates fabricating devices with YBCO, and the material is also sensitive to degradation from humidity. | 1 | Solid-state chemistry |
These electrodes were developed to offer a high-throughput yet low-cost alternative to conventional electrode structures for DEP. Rather than use photolithographic methods or other microengineering approaches, DEP-well electrodes are constructed from stacking successive conductive and insulating layers in a laminate, after which multiple "wells" are drilled through the structure. If one examines the walls of these wells, the layers appear as interdigitated electrodes running continuously around the walls of the tube. When alternating conducting layers are connected to the two phases of an AC signal, a field gradient formed along the walls moves cells by DEP.
DEP-wells can be used in two modes; for analysis or separation. In the first, the dielectrophoretic properties of cells can be monitored by light absorption measurements: positive DEP attracts the cells to the wall of the well, thus when probed with a light beam the well the light intensity increases through the well. The opposite is true for negative DEP, in which the light beam becomes obscured by the cells. Alternatively, the approach can be used to build a separator, where mixtures of cells are forced through large numbers (>100) of wells in parallel; those experiencing positive DEP are trapped in the device whilst the rest are flushed. Switching off the field allows release of the trapped cells into a separate container. The highly parallel nature of the approach means that the chip can sort cells at much higher speeds, comparable to those used by MACS and FACS.
This approach offers many advantages over conventional, photolithography-based devices but reducing cost, increasing the amount of sample which can be analysed simultaneously, and the simplicity of cell motion reduced to one dimension (where cells can only move radially towards or away from the centre of the well). Devices manufactured to use the DEP-well principle are marketed under the DEPtech brand. | 0 | Colloidal Chemistry |
Dielectrophoresis can be used to manipulate, transport, separate and sort different types of particles. DEP is being applied in fields such as medical diagnostics, drug discovery, cell therapeutics, and particle filtration.
DEP has been also used in conjunction with semiconductor chip technology for the development of DEP array technology for the simultaneous management of thousands of cells in microfluidic devices. Single microelectrodes on the floor of a flow cell are managed by a CMOS chip to form thousands of dielectrophoretic "cages", each capable of capturing and moving one single cell under control of routing software.
As biological cells have dielectric properties, dielectrophoresis has many biological and medical applications. Instruments capable of separating cancer cells from healthy cells have been made as well as isolating single cells from forensic mixed samples. Platelets have been separated from whole blood with a DEP-activated cell sorter.
DEP has made it possible to characterize and manipulate biological particles like blood cells, stem cells, neurons, pancreatic β cells, DNA, chromosomes, proteins and viruses.
DEP can be used to separate particles with different sign polarizabilities as they move in different directions at a given frequency of the AC field applied. DEP has been applied for the separation of live and dead cells, with the remaining live cells still viable after separation or to force contact between selected single cells to study cell-cell interaction.
DEP has been used to separate strains of bacteria and viruses. DEP can also be used to detect apoptosis soon after drug induction measuring the changes in electrophysiological properties. | 0 | Colloidal Chemistry |
Mycosubtilin is a natural lipopeptide. It is produced by the strains of Bacillus spp mainly by Bacillus subtilis. It was discovered due to its antifungal activities. It belongs to the family of iturin lipopeptides | 0 | Colloidal Chemistry |
Zeta potential is the electrical potential at the slipping plane. This plane is the interface which separates mobile fluid from fluid that remains attached to the surface.
Zeta potential is a scientific term for electrokinetic potential in colloidal dispersions. In the colloidal chemistry literature, it is usually denoted using the Greek letter zeta (ζ), hence ζ-potential. The usual units are volts (V) or, more commonly, millivolts (mV). From a theoretical viewpoint, the zeta potential is the electric potential in the interfacial double layer (DL) at the location of the slipping plane relative to a point in the bulk fluid away from the interface. In other words, zeta potential is the potential difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle.
The zeta potential is caused by the net electrical charge contained within the region bounded by the slipping plane, and also depends on the location of that plane. Thus, it is widely used for quantification of the magnitude of the charge. However, zeta potential is not equal to the Stern potential or electric surface potential in the double layer, because these are defined at different locations. Such assumptions of equality should be applied with caution. Nevertheless, zeta potential is often the only available path for characterization of double-layer properties.
The zeta potential is an important and readily measurable indicator of the stability of colloidal dispersions. The magnitude of the zeta potential indicates the degree of electrostatic repulsion between adjacent, similarly charged particles in a dispersion. For molecules and particles that are small enough, a high zeta potential will confer stability, i.e., the solution or dispersion will resist aggregation. When the potential is small, attractive forces may exceed this repulsion and the dispersion may break and flocculate. So, colloids with high zeta potential (negative or positive) are electrically stabilized while colloids with low zeta potentials tend to coagulate or flocculate as outlined in the table.
Zeta potential can also be used for the pKa estimation of complex polymers that is otherwise difficult to measure accurately using conventional methods. This can help studying the ionisation behaviour of various synthetic and natural polymers under various conditions and can help in establishing standardised dissolution-pH thresholds for pH responsive polymers. | 0 | Colloidal Chemistry |
Lecithins have emulsification and lubricant properties, and are a surfactant. They can be completely metabolized (see inositol) by humans, so are well tolerated by humans and nontoxic when ingested.
The major components of commercial soybean-derived lecithin are:
* 33–35% soybean oil
* 20–21% phosphatidylinositols
* 19–21% phosphatidylcholine
* 8–20% phosphatidylethanolamine
* 5–11% other phosphatides including phosphatidylserine
* 5% free carbohydrates
* 2–5% sterols
* 1% moisture
Lecithin is used for applications in human food, animal feed, pharmaceuticals, paints, and other industrial applications.
Applications include:
* In the pharmaceutical industry, it acts as a wetting agent, stabilizing agent and a choline enrichment carrier, helps in emulsification and encapsulation, and is a good dispersing agent. It can be used in manufacture of intravenous fat infusions and for therapeutic use.
* In animal feed, it enriches fat and protein and improves pelletization.
* In the paint industry, it forms protective coatings for surfaces with painting and printing ink, helps as a rust inhibitor, is a colour intensifying agent, catalyst, conditioning aid modifier, and dispersing aid; it is a good stabilizing and suspending agent, emulsifier, and wetting agent, helps in maintaining uniform mixture of several pigments, helps in grinding of metal oxide pigments, is a spreading and mixing aid, prevents hard settling of pigments, eliminates foam in water-based paints, and helps in fast dispersion of latex-based paints.
* Lecithin also may be used as a release agent for plastics, an anti-sludge additive in motor lubricants, an anti-gumming agent in gasoline, and an emulsifier, spreading agent, and antioxidant in textile, rubber, and other industries. | 0 | Colloidal Chemistry |
Graphitic carbon nitride can be made by polymerization of cyanamide, dicyandiamide or melamine. The firstly formed polymeric CN structure, melon, with pendant amino groups, is a highly ordered polymer. Further reaction leads to more condensed and less defective CN species, based on tri-s-triazine (CN) units as elementary building blocks.
Graphitic carbon nitride can also be prepared by electrodeposition on Si(100) substrate from a saturated acetone solution of cyanuric trichloride and melamine (ratio =1: 1.5) at room temperature.
Well-crystallized graphitic carbon nitride nanocrystallites can also be prepared via benzene-thermal reaction between CNCl and NaNH at 180–220 °C for 8–12 h.
Recently, a new method of syntheses of graphitic carbon nitrides by heating at 400-600 °C of a mixture of melamine and uric acid in the presence of alumina has been reported. Alumina favored the deposition of the graphitic carbon nitrides layers on the exposed surface. This method can be assimilated to an in situ chemical vapor deposition (CVD). | 1 | Solid-state chemistry |
Schmidt was born in Berlin in 1919 and went to high school in Munich, where his father was a professor of chemistry. Being the son of a Jewish mother, Gerhard was forced to leave Germany at the age of 16, after the Nazis came to power; he spent a year in Switzerland, then moved to England, where he finished high school in 1938. He then won a scholarship to study at the University of Oxford (Oriel College). He earned a master's degree in organic chemistry in 1942 under the guidance of Robert Robinson, and a doctorate in X-ray crystallography under Dorothy Hodgkin in 1948. Both of his supervisors were later awarded Nobel Prizes in chemistry.
During his doctoral studies, Schmidt took part in structural studies of biologically important molecules, focusing on the structure of the antibacterial natural peptide Gramicidin S using the method of X-ray crystallography. During this period he supervised another student of Hodgkin, Margaret Roberts, later Margaret Thatcher.
After the breakout of World War II, Schmidt was forced to interrupt his studies. Being an emigrant from Germany, he was deported in July 1940, together with 200 other “enemy aliens,” to a detention camp in Australia. In August 1941, he was finally cleared and returned to England. Later in life, Schmidt liked to date some of his most original ideas in chemistry to this deportation period. | 1 | Solid-state chemistry |
Industrially, NaH is prepared by introducing molten sodium into mineral oil with hydrogen at atmospheric pressure and mixed vigorously at ~8000 rpm. The reaction is especially rapid at 250−300 °C.
The resultant suspension of NaH in mineral oil is often directly used, such as in the production of diborane. | 1 | Solid-state chemistry |
In 1974 he received the CNRS Silver Medal and in 1997 the CNRS Gold Medal and the Prix Paul Pascal from the French Academy of Sciences. In 1992 he was awarded the Gay-Lussac Humboldt Prize. Rouxel received the Alexander von Humboldt Research Award (1993) and gave the Debye Lecture of the Cornell University section of the American Chemical Society. He was Knight of the Legion of Honor (1988, officer from 1997) and officer of the Ordre national du Mérite and commander of the Palmes académiques. In 1988 he became a member of the Académie des sciences and he was a member of the American Academy of Arts and Sciences (1992), the Academia Europaea, the German National Academy of Sciences Leopoldina (1997) and the Indian Academy of Sciences. | 1 | Solid-state chemistry |
Lamellar phase refers generally to packing of polar-headed long chain nonpolar-tail molecules in an environment of bulk polar liquid, as sheets of bilayers separated by bulk liquid. In biophysics, polar lipids (mostly, phospholipids, and rarely, glycolipids) pack as a liquid crystalline bilayer, with hydrophobic fatty acyl long chains directed inwardly and polar headgroups of lipids aligned on the outside in contact with water, as a 2-dimensional flat sheet surface. Under transmission electron microscope (TEM), after staining with polar headgroup reactive chemical osmium tetroxide, lamellar lipid phase appears as two thin parallel dark staining lines/sheets, constituted by aligned polar headgroups of lipids. Sandwiched between these two parallel lines, there exists one thicker line/sheet of non-staining closely packed layer of long lipid fatty acyl chains. This TEM-appearance became famous as Robertson's unit membrane - the basis of all biological membranes, and structure of lipid bilayer in unilamellar liposomes. In multilamellar liposomes, many such lipid bilayer sheets are layered concentrically with water layers in between.
In lamellar lipid bilayers, polar headgroups of lipids align together at the interface of water and hydrophobic fatty-acid acyl chains align parallel to one another hiding away from water. The lipid head groups are somewhat more tightly packed than relatively fluid hydrocarbon fatty acyl long chains. The lamellar lipid bilayer organization, thus reveals a flexibility gradient of increasing freedom of motions from near the head-groups towards the terminal fatty-acyl chain methyl groups. Existence of such a dynamic organization of lamellar phase in liposomes as well as biological membranes can be confirmed by spin label electron paramagnetic resonance and high resolution nuclear magnetic resonance spectroscopy studies of biological membranes and liposomes.
In soft matter science, where physics and chemistry meet biological science, a bilayer lamellar phase has been recently created from fluorinated silica, and it has been projected for use as a shear-thinning lubricant. | 0 | Colloidal Chemistry |
There are several methods for measuring particle size and particle size distribution. Some of them are based on light, other on ultrasound, or electric field, or gravity, or centrifugation. The use of sieves is a common measurement technique, however this process can be more susceptible to human error and is time consuming. Technology such as dynamic image analysis (DIA) can make particle size distribution analyses much easier. This approach can be seen in instruments like Retsch Technology's CAMSIZER or the Sympatec QICPIC series of instruments. They still lack the capability of inline measurements for real time monitoring in production environments. Therefore, inline imaging devices like the SOPAT system are most efficient.
Machine learning algorithms are used to increase the performance of particle size measurement. This line of research can yield low-cost and real time particle size analysis.
In all methods the size is an indirect measure, obtained by a model that transforms, in abstract way, the real particle shape into a simple and standardized shape, like a sphere (the most usual) or a cuboid (when minimum bounding box is used), where the size parameter (ex. diameter of sphere) makes sense. Exception is the mathematical morphology approach, where no shape hypothesis is necessary.
Definition of the particle size for an ensemble (collection) of particles presents another problem. Real systems are practically always polydisperse, which means that the particles in an ensemble have different sizes. The notion of particle size distribution reflects this polydispersity. There is often a need for a certain average particle size for the ensemble of particles. | 0 | Colloidal Chemistry |
At the University of Houston, Guloy investigates the structural and physical properties of Zintl phases and intermetallic materials with a focus on transport properties and novel materials. He has been a professor of chemistry at the University of Houston since 1993 rising through the ranks to become the John and Rebecca Moores Professor at the University of Houston in 2015. In 1998 he was awarded an National Science Foundation CAREER Award. He was a visiting professor at Sun Yat-Sen University in 2015 and was awarded the Distinguished Visiting Scholar-Lecturer Award from Chungnam National University, Daejun, Korea in 2009. | 1 | Solid-state chemistry |
A nanogenizer, also known as a high-pressure homogenizer or a microfluidizer, is a device used to create small droplets or particles by applying high pressure to a liquid mixture. These devices can be used to produce nanoemulsions, as well as other types of emulsions and suspensions. They work by passing the mixture through a small orifice under high pressure, which causes the liquid to be sheared and broken into small droplets or particles. The size of the droplets or particles can be controlled by adjusting the pressure and the design of the orifice. | 0 | Colloidal Chemistry |
Most ionic compounds are very brittle. Once they reach the limit of their strength, they cannot deform malleably, because the strict alignment of positive and negative ions must be maintained. Instead the material undergoes fracture via cleavage. As the temperature is elevated (usually close to the melting point) a ductile–brittle transition occurs, and plastic flow becomes possible by the motion of dislocations. | 1 | Solid-state chemistry |
Particle deposition can be followed by various experimental techniques. Direct observation of deposited particles is possible with an optical microscope, scanning electron microscope, or the atomic force microscope. Optical microscopy has the advantage that the deposition of particles can be followed in real time by video techniques and the sequence of images can be analyzed quantitatively. On the other hand, the resolution of optical microscopy requires that the particle size investigated exceeds at least 100 nm.
An alternative is to use surface sensitive techniques to follow particle deposition, such as reflectivity, ellipsometry, surface plasmon resonance, or quartz crystal microbalance. These techniques can provide information on the amount of particles deposited as a function of time with good accuracy, but they do not permit to obtain information concerning the lateral arrangement of the particles.
Another approach to study particle deposition is to investigate their transport in a chromatographic column. The column is packed with large particles or with a porous medium to be investigated. Subsequently, the column is flushed with the solvent to be investigated, and the suspension of the small particles is injected at the column inlet. The particles are detected at the outlet with a standard chromatographic detector. When particles deposit in the porous medium, they will not arrive at the outlet, and from the observed difference the deposition rate coefficient can be inferred. | 0 | Colloidal Chemistry |
For elastomeric cellular solids, as the foam is compressed, first it behaves elastically as the cell walls bend, then as the cell walls buckle there is yielding and breakdown of the material until finally the cell walls crush together and the material ruptures. This is seen in a stress-strain curve as a steep linear elastic regime, a linear regime with a shallow slope after yielding (plateau stress), and an exponentially increasing regime. The stiffness of the material can be calculated from the linear elastic regime where the modulus for open celled foams can be defined by the equation:
where is the modulus of the solid component, is the modulus of the honeycomb structure, is a constant having a value close to one, is the density of the honeycomb structure, and is the density of the solid. The elastic modulus for closed cell foams can be described similarly by:
where the only difference is the exponent in the density dependence. However, in real materials, a closed-cell foam has more material at the cell edges which makes it more closely follow the equation for open-cell foams. The ratio of the density of the honeycomb structure compared with the solid structure has a large impact on the modulus of the material. Overall, foam strength increases with density of the cell and stiffness of the matrix material. | 0 | Colloidal Chemistry |
PAC uses radioactive probes, which have an intermediate state with decay times of 2 ns to approx. 10 μs, see example In in the picture on the right. After electron capture (EC), indium transmutates to cadmium. Immediately thereafter, the cadmium nucleus is predominantly in the excited 7/2+ nuclear spin and only to a very small extent in the 11/2- nuclear spin, the latter should not be considered further. The 7/2+ excited state transitions to the 5/2+ intermediate state by emitting a 171 keV γ-quantum. The intermediate state has a lifetime of 84.5 ns and is the sensitive state for the PAC. This state in turn decays into the 1/2+ ground state by emitting a γ-quantum with 245 keV. PAC now detects both γ-quanta and evaluates the first as a start signal, the second as a stop signal.
Now one measures the time between start and stop for each event. This is called coincidence when a start and stop pair has been found. Since the intermediate state decays according to the laws of radioactive decay, one obtains an exponential curve with the lifetime of this intermediate state after plotting the frequency over time. Due to the non-spherically symmetric radiation of the second γ-quantum, the so-called anisotropy, which is an intrinsic property of the nucleus in this transition, it comes with the surrounding electrical and/or magnetic fields to a periodic disorder (hyperfine interaction). The illustration of the individual spectra on the right shows the effect of this disturbance as a wave pattern on the exponential decay of two detectors, one pair at 90° and one at 180° to each other. The waveforms to both detector pairs are shifted from each other. Very simply, one can imagine a fixed observer looking at a lighthouse whose light intensity periodically becomes lighter and darker. Correspondingly, a detector arrangement, usually four detectors in a planar 90 ° arrangement or six detectors in an octahedral arrangement, "sees" the rotation of the core on the order of magnitude of MHz to GHz.
According to the number n of detectors, the number of individual spectra (z) results after z=n²-n, for n=4 therefore 12 and for n=6 thus 30. In order to obtain a PAC spectrum, the 90° and 180° single spectra are calculated in such a way that the exponential functions cancel each other out and, in addition, the different detector properties shorten themselves. The pure perturbation function remains, as shown in the example of a complex PAC spectrum. Its Fourier transform gives the transition frequencies as peaks.
, the count rate ratio, is obtained from the single spectra by using:
Depending on the spin of the intermediate state, a different number of transition frequencies show up. For 5/2 spin, 3 transition frequencies can be observed with the ratio ω+ω=ω. As a rule, a different combination of 3 frequencies can be observed for each associated site in the unit cell.
PAC is a statistical method: Each radioactive probe atom sits in its own environment. In crystals, due to the high regularity of the arrangement of the atoms or ions, the environments are identical or very similar, so that probes on identical lattice sites experience the same hyperfine field or magnetic field, which then becomes measurable in a PAC spectrum. On the other hand, for probes in very different environments, such as in amorphous materials, a broad frequency distribution or no is usually observed and the PAC spectrum appears flat, without frequency response. With single crystals, depending on the orientation of the crystal to the detectors, certain transition frequencies can be reduced or extinct, as can be seen in the example of the PAC spectrum of zinc oxide (ZnO). | 1 | Solid-state chemistry |
There is considerable interest in using InS to replace the semiconductor CdS (cadmium sulfide) in photoelectronic devices. β-InS has a tunable band gap, which makes it attractive for photovoltaic applications, and it shows promise when used in conjunction with TiO in solar panels, indicating that it could replace CdS in that application as well. Cadmium sulfide is toxic and must be deposited with a chemical bath, but indium(III) sulfide shows few adverse biological effects and can be deposited as a thin film through less hazardous methods.
Thin films β-InS can be grown with varying band gaps, which make them widely applicable as photovoltaic semiconductors, especially in heterojunction solar cells.
Plates coated with beta-InS nanoparticles can be used efficiently for PEC (photoelectrochemical) water splitting. | 1 | Solid-state chemistry |
Phosphorene is a two-dimensional material consisting of phosphorus. It consists of a single layer of black phosphorus, the most stable allotrope of phosphorus. Phosphorene is analogous to graphene (single layer graphite). Among two-dimensional materials, phosphorene is a competitor to graphene because it has a nonzero fundamental band gap that can be modulated by strain and the number of layers in a stack. Phosphorene was first isolated in 2014 by mechanical exfoliation. Liquid exfoliation is a promising method for scalable phosphorene production. | 1 | Solid-state chemistry |
The most noticeable form of foam is foam floating on the stock surface. It is easy to monitor and relatively easy to handle and is more a cosmetic issue. Surface foam may cause problems with liquid levels and give overflow leading to pools of oils around the equipment which is a safety concern.
Additionally, this might reduce the process speed and availability of process equipment. The main mechanical problem tends to be when foam enters the system as air is a poor lubricant, meaning metal to metal contact can occur. | 0 | Colloidal Chemistry |
The exploding wire method or EWM is a way to generate plasma that consists in sending a strong enough pulse of electric current through a thin wire of some electrically conductive material. The resistive heating vaporizes the wire, and an electric arc through that vapor creates an explosive shockwave.
Exploding wires are used as detonators for explosives, as momentary high intensity light sources, and in the production of metal nanoparticles. | 0 | Colloidal Chemistry |
In 1993, Lee received the MacArthur Award for his work in the field of physics and chemistry. In addition, he has received an award from the Alfred P. Sloan Foundation for his continued research.
In 1999, Lee joined Cornell University as a professor of solid state chemistry in the chemistry and chemical biology department from the University of Michigan, where he had been associate professor of chemistry since 1993 and where he had been recognized as both a MacArthur and a Sloan fellow. He was also a visiting scientist at Cornell in 1995.
He currently continues his teaching career at Cornell, where he instructs students in (honors) general chemistry and introduction to chemistry courses. During the past 10 years, Lee has devoted his summer to helping incoming freshmen learn basic chemistry to prepare them for the academic year. This has been considered part of Lee's philanthropic work, as he teaches these summer courses probono.
His current research involves developing stronger porous solids in which all the host porous bonds are covalent in character. Lee is also researching ways to introduce cross-linkable guests (such as di-isocyanides or disilyltriflates) which will react with nucleophilic groups, leading to a fully covalent organic porous solid. He also hopes to develop a long range order in intermetallic phases: Examine noble metal alloys where unit cell dimensions range from just a few, to almost 104 Å. | 1 | Solid-state chemistry |
The core of an aquasome can be made from either ceramic or polymeric materials. Examples of such polymers include acrylates and gelatin. However, because ceramic materials are more ordered due to their naturally occurring crystalline structure, they are more often preferred as the material type for the core. Some of the most common ceramic materials used in the formation of an aquasome core include tin oxide, calcium phosphate, and even diamond. Another characteristic that ceramic materials provide is enhanced binding of the carbohydrate layer due to the high surface energy present on the orderly surface. The binding affinity of the carbohydrate layer also reduces surface tension for its bond to the ceramic core. The first aquasomes fabricated with a nanocrystalline core using ceramic material are detailed in Kossovsky et al. in 1996. Calcium phosphate ceramic nanoparticles (brushite) were first prepared via the method of solution precipitation and sonication. Precipitation methods are the most common techniques employed when synthesizing the core of an aquasome as they offer control over the homogeneity and purity of the precipitated products, which are important design features in the core structure. Once the cores are prepared, they are separated by centrifugation and then washed to remove any salt byproducts from the solution precipitation process. Finally, the washed cores are passed through a Millipore filter to selectively isolate core particles of a certain size. | 0 | Colloidal Chemistry |
In the late 20th and early 21st century, there has been a global movement towards the phase-out of polystyrene foam as a single use plastic (SUP). Early bans of polystyrene foam intended to eliminate ozone-depleting chlorofluorocarbons (CFCs), formerly a major component.
Expanded polystyrene, often termed Styrofoam, is a contributor of microplastics from both land and maritime activities. Polystyrene is not biodegradeable but is susceptible to photo-oxidation, and degrades slowly in the ocean as microplastic marine debris. Animals do not recognize polystyrene foam as an artificial material, may mistake it for food, and show toxic effects after substantial exposure.
Full or partial bans of expanded and polystyrene foam commonly target disposable food packaging. Such bans have been enacted through national legislation globally, and also at sub-national or local levels in many countries. | 0 | Colloidal Chemistry |
Aerogels are able to fill large volumes with minimal material yielding special properties such as low density and low thermal conductivity. These aerogels tend to have internal structures categorized as open or closed cell structures, the same cell structure that is used to define many 3-dimensional honeycomb biofoams. Aerogels are also being engineered to mirror the internal foam structures of animal hairs (see Figure 3). These biomimetic aerogels are being actively researched for their promising elastic and insulative properties. | 0 | Colloidal Chemistry |
In molecular biology, Pulmonary surfactant protein D (SP-D) is a protein domain predominantly found in lung surfactant. This protein plays a special role; its primary task is to act as a defence protein against any pathogens that may invade the lung. It also plays a role in lubricating the lung and preventing it from collapse. It has an interesting structure as it forms a triple-helical parallel coiled coil, helps the protein to fold into a trimer. | 0 | Colloidal Chemistry |
Nonstoichiometry is pervasive for metal oxides, especially when the metal is not in its highest oxidation state. For example, although wüstite (ferrous oxide) has an ideal (stoichiometric) formula , the actual stoichiometry is closer to . The non-stoichiometry reflect the ease of oxidation of to effectively replacing a small portion of with two thirds their number of . Thus for every three "missing" ions, the crystal contains two ions to balance the charge. The composition of a non-stoichiometric compound usually varies in a continuous manner over a narrow range. Thus, the formula for wüstite is written as , where x is a small number (0.05 in the previous example) representing the deviation from the "ideal" formula. Nonstoichiometry is especially important in solid, three-dimensional polymers that can tolerate mistakes. To some extent, entropy drives all solids to be non-stoichiometric. But for practical purposes, the term describes materials where the non-stoichiometry is measurable, usually at least 1% of the ideal composition. | 1 | Solid-state chemistry |
Through much of his life, Berzelius suffered various medical ailments. These included recurrent migraine headaches and then later on he suffered from gout. He also had episodes of depression.
In 1818, Berzelius had a nervous breakdown, said to be due to the stress of his work. The medical advice he received was to travel and take vacation. However, during this time, Berzelius traveled to France to work in the chemical laboratories of Claude Louis Berthollet.
In 1835, at the age of 56, he married Elizabeth Poppius, the 24-year-old daughter of a Swedish cabinet minister.
He died on 7 August 1848 at his home in Stockholm, where he had lived since 1806. He is buried in the Solna Cemetery. | 1 | Solid-state chemistry |
Through the process of saponification, fats (like tallow, pig, and bone fats) or vegetable oils react with sodium hydroxide to form the sodium salts of fatty acids and glycerin. The resulting mixture is known as soft soap, which serves as a precursor for hard soap production. After adding sodium chloride (a process known as salting out), the soap nucleus rises and separates. The water-soluble glycerin and unwanted fat residues remain in the solution (see also soap). | 0 | Colloidal Chemistry |
Prewitt was a Fellow of the Japan Society for the Promotion of Science in 1983. He was the vice president and president of the Mineralogical Society of America in 1983 and 1984, respectively. He was awarded the Roebling Medal from the Mineralogical Society of America in 2003. He received the inaugural Medal for Excellence from the International Mineralogical Association in 2008. | 1 | Solid-state chemistry |
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