Chain-End Modification of Polysilane and SNOM observation of their Smectic Phase

Abstract

Liquid crystal (LC) phases formed by rod-like molecules have been extensively studied both theoretically and experimentally. Since the initial theoretical approach in 1950s, it has been shown that systems of hard rod-like particles give rise to the most common liquid crystal sequence of nematic―smectic―columnar phases based on computer simulations. On the experimental side, we recently reported that the predicted LC phase sequence has been successfully reproduced in the thermotropic LC system of the carefully prepared polysilane with an exquisitely narrow molecular weight distribution. In this work, we performed the modification of Si-H end groups of polysilane with a fluorescent dye, and observed the segregation of the dye in between the smectic layers with atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM).