Preparation of cyanine complex micro-domes in self-organized dewetted films

摘要

When an organic solution of a polymer is dropped on a hydrophilic surface, e. g. a glass substrate, polymer film is dewetted on the surface during evaporation of solvent, leaving several polymer patterns such as stripes, dots (domes) and polygon networks. Dewetting phenomena are not only observed in polymer films but also in low mass molecular films. A cyanine-dye complex was prepared from a cationic cyanine dye and an anionic amphiphile. When a chloroform solution of the cyanine complex was spread on a glass substrate by a roller, micro-domes of the cyanine-dye complex formed in dewetted films. The roller draws the three-phase line (the air-solid-liquid boundary of the droplet of the chloroform solution) with a constant rate, which leads to a two-dimensional ordered array of micro-domes. Typically, the size of micro-domes obtained were several or several ten micrometers in width and one micrometer in height. The diameter and height of micro-domes depended on the roller speed. Fluorescence microscopy shows that the cyanine-dye complex is condensed in each micro-dome. The micro-domes consist of polycrystals and gave fluorescence emission that was difference from a chloroform solution of the cyanine-dye complex.