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 ΔT (difference between on- and off-state transmittances) of >85% at a low driving voltage.
KEYWORDS: photoinitiator, electro-optical properties, thiol−acrylate polymerization, driving voltage, smart windows