Effect of the Concentration Gradient on Molecular Alignment by Scanning Wave Photopolymerization

Abstract

Macroscopic and precise alignment control of functional molecules can provide increased functionality and enhanced device performance. However, even the most powerful current method has some limitations, such as the need for polarized light and photoresponsive dye molecules. We reported an alignment process based on a new concept of scanning wave photopolymerization (SWaP) that achieves an arbitrary alignment pattern by spatiotemporal light-triggered molecular diffusion. Here, we investigate the effect of crosslinker on molecular alignment by SWaP. We found that the controlled concentration gradient of polymer added with the optimal amount of crosslinker improved the degree of alignment of the liquid-crystalline polymers. SWaP could be employed as a simple and versatile fabrication process for preparing highly functional materials and devices that require alignment control.