Title: Liquid crystal induced elasto-capillary suppression of crack formation in thin colloidal films,
Abstract: Drying of colloidal droplets on solid, rigid substrates is associated with a
capillary pressure developing within the droplet. In due course of time, the
capillary pressure builds up due to droplet evaporation resulting in the
formation of a colloidal thin film that is prone to crack formation. In this
study, we show that introducing a minimal amount of nematic liquid crystal
(NLC) can completely suppress the crack formation. The mechanism behind the
curbing of the crack formation may be attributed to the capillary
stress-absorbing cushion provided by the elastic arrangements of the liquid
crystal at the substrate-droplet interface. Cracks and allied surface
instabilities are detrimental to the quality of the final product like surface
coatings, and therefore, its suppression by an external inert additive is a
promising technique that will be of immense importance for several industrial
applications. We believe this fundamental investigation of crack suppression
will open up an entire avenue of applications for the NLCs in the field of
coatings, broadening its already existing wide range of benefits.