Molybdenum disulfide (MoS2), which is ubiquitously used as a solid lubricant, has recently been shown to have a two-dimensional (2D) form that is similar to graphene. But, when thinned down to less than a nanometer thick, MoS2 demonstrates properties with great promise as a functional material for electronic devices and surface coatings. Researchers at the University of Illinois at Urbana-Champaign have developed a new approach to dynamically tune the micro- and nano-scale roughness of atomically thin MoS2, and consequently the appropriate degree of hydrophobicity for various potential MoS2-based applications. "The knowledge of how new materials interact with water is a fundamental," explained SungWoo Nam, an assistant professor of mechanical science and engineering at Illinois. "Whereas the wettability of its more famous cousin, graphene, has been substantially investigated, that of atomically thin MoS2—in particular atomically thin MoS2 with micro- and nano-scale roughness—has remained relatively unexplored despite its strong potential for fundamental research and device applications. Notably, systematic study of how hierarchical microscale and nanoscale roughness of MoS2 influence its wettability has been lacking in the scientific community." "This work will provide a new approach to dynamically tune the micro- and nano-scale roughness of atomically thin MoS2 and consequently the appropriate degree of hydrophobicity for various potential MoS2-based applications," stated Jonghyun Choi, a mechanical engineering graduate student and first author of the article, "Hierarchical, Dual-Scale Structures of Atomically Thin MoS2 for Tunable Wetting," appearing in the journal, Nano Letters. "These include waterproof electronic devices with superhydrophobicity with water contact angle greater than 150 degrees. It may also be useful for medical applications with reduced hydrophobicity (WCA less than 100 degrees) for effective contact with biological substances. " According to the authors, this study, expands the toolkit to allow tunable wettability of 2D materials, many of which are just beginning to be discovered. "When deformed and patterned to produce micro- and nano-scale structures, MoS2 shows promise as a functional material for hydrogen evolution catalysis systems, electrodes for alkali metal-ion batteries, and field-emission arrays," Nam added. "The results should also contribute to future MoS2-based applications, such as tunable wettability coatings for desalination and hydrogen evolution." Jonghyun Choi et al, Hierarchical, Dual-Scale Structures of Atomically Thin MoSfor Tunable Wetting, (2017). Citation: Nano-level lubricant tuning improves material for electronic devices and surface coatings (2017, February 10) retrieved 14 April 2020 from https://phys.org/news/2017-02-nano-level-lubricant-tuning-material-electronic.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Researchers at the University of Illinois at Chicago - Champaign have developed a method of tuning the micro and nano - scale roughness of molybdenum disulfide ( MoS2 ) . It , which is used as a solid lubricant , has been shown to have a 2D version , which is similar to graphene . However , when thinned to below a nanometre in thickness , MoS2 has the potential to act as a " functional material " for electrical devices and a coating for certain applications . These latest developments will also enhance fine - tuning hyrophobicity in future applications . " The knowledge of how new materials interact with water is a fundamental , " said an assistant professor at the university , SungWoo Kim .