Infrared microspectroscopic investigation of the diffusion of E7 into poly(butyl methacrylate)

The components of a liquid crystal mixture (E7) have been shown to diffuse at different rates in polymer-dispersed liquid crystals (PDLCs). It was observed in this work that liquid crystals of different molecular weights diffuse into poly(butyl methacrylate) (PBMA) at different rates at a constant temperature. It was also determined that the components in a liquid crystal mixture diffuse into the polymer at different rates. The effect is quite small under normal conditions, so elevated temperatures, simplified diffusion boundaries, and extended time scales were employed to magnify the diffusion separation effects for study. This work demonstrates that the components of E7 diffuse at different rates. Practically, the short phase separation times experienced during the generation of a PDLC may be insufficient to promote this effect to the point where optical properties are adversely affected.