Two-dimensional molecular orientation by photopolymerization induced molecular diffusion

Abstract

Precise molecular orientation in polymer films enables to yield the wide variety of functionalities such as mechanical, optical or electrical properties. Generally, such polymer films are easily fabricated with the assistance of an alignment layer typically processed by external stimuli: mechanical stress or irradiation with polarized light. In this study, we directly fabricated polymer films having macroscopic and precise molecular orientation in one or two dimensions simply by photopolymerization with the spatial gradient of light intensity. The photopolymerization generates molecular diffusion and flow providing orientation of anisotropic molecules without either an alignment layer or polarized light.