Formation of spiral microstructures during crystallization of 4,4‘-azoxyanisole from a benzene solution

Abstract

A phenomenon of formation of multiple “coffee rings” consisting of microcrystals in the 4,4‘-azoxyanisole - benzene system was experimentally and theoretically investigated. It is shown that by changing of the geometry of a drop, for example, by placing a metal ball in its center it is possible to fundamentally change the geometry of the “coffee ring”. Assumptions were made about the physical nature of the effect of the formation of a “coffee ring” of a spiral shape. The proposed geometric model of this phenomenon reflects well the physical processes occurring during spiral crystallization, and the model is in good agreement with the experimental data obtained by gravimetry. New approaches to the formation of microstructures of functional materials with a thermotropic liquid crystal phase on a glass substrate can be used to create devices for nano – and microelectronics and optical technology.