Optimization of LC droplet size and electro‐optical properties of acrylate‐based polymer‐dispersed liquid crystal by controlling photocure rate

Abstract

We investigated the effects of the different content ratios of 2-ethylhexylacrylate (2-EHA) and 2-ethylhexylmethacrylate (2-EHMA) on the relationships among the photopolymerization rate, morphology of liquid crystals (LCs) droplets, and electrooptical properties of trifunctional urethane acrylate-based polymer-dispersed liquid crystal (PDLC) systems. Photo-differential scanning calorimetry (DSC) analysis and resistivity measurement revealed that increasing 2-EHMA content gradually decreased the photocure rate of trifunctional urethane acrylate-based PDLCs, which prolonged the phase separation between the LC molecules and the prepolymers. Morphological observations and electro-optical measurements demonstrated that trifunctional urethane acrylate-based PDLCs with the 2-EHA:2-EHMA ratios from 4:1 to 3:2 in weight percent formed the favorable microstructures of LC droplets being within the range of 1-5 mm to scatter light efficiently and showed the satisfactory off-state opacity and on-state transmittance and the relatively low-driving voltage. The microstructures of LC droplets and electro-optical properties of trifunctional urethane acrylatebased PDLCs could be usefully optimized by controlling the photocure rate using the different 2-EHA/2-EHMA content ratios.

Ordering kinetics of a conserved binary mixture with a nematic liquid crystal component

“…The systems involving liquid crystals are investigated via simulation [47,53,31,45,11] and the phase diagram indicating where transitions between the nematic and isotropic phases of the liquid crystal occur is analyzed [47,53,40]. Recently, applications of models for similar systems include polymer-dispersed liquid crystals [44,1,34,48,19,21,22,39,29], diblock copolymers [32,46], and other cases of problems involving phase separation [5,27,33,38,6,41,42,61].…”

High-refractive index acrylate polymers for applications in nanoimprint lithography

“…Acrylate polymers have been extensively used in a broad variety of fields owing to their facile synthesis, excellent optical transparency, convenient processability and great mechanical properties [41][42][43][44][45][46]. Most of the existing acrylate polymers exhibit low refractive index (~1.50), which considerably prevents their prospective application in advanced optical devices [47].…”

Glass reflow process for microsystem applications

“…There is another mechanism of light modulation where the light scattering of liquid crystal molecules is controlled by outer electric field that results in low optical modulator [31]. Additionally, the switching speed and the operation voltage depend on the liquid crystal molecules (sizes, shapes, etc) [32].…”