Effect of the Photoinitiator Concentration on the Electro-optical Properties of Thiol–Acrylate-Based PDLC Smart Windows

Polymer-dispersed liquid crystals (PDLCs), an indispensable class of electrically switchable materials, where nano- or microsized liquid crystal (LC) droplets are phase-separated from the polymer matrix, have been widely used in the fabrication of highly efficient and systematic smart windows. In this paper, we explored the effect of the photoinitiator concentration on the morphology and electro-optical properties of PDLC films based on thiol and acrylates. We prepared PDLC films using various concentrations of the photoinitiator, while keeping the concentrations of LC and monomers constant. We observed that the concentration of the photoinitiator directly influences the phase separation process, which in turn determines the morphology and electro-optical characteristics of the PDLC film. Thus, an optimized amount of the photoinitiator is required to prepare PDLC films with high transmittance and low switching time, haze, and power consumption. The optimized photoinitiator concentration can have a transmittance Δ T (difference between on- and off-state transmittances) of >85% at a low driving voltage.