Heteroatom-Terminated\nAcrylate-Based Polymer-Dispersed\nLiquid Crystal Composite Films with High Contrast Ratio and Low Driving\nVoltage

A series of polymer-dispersed liquid\ncrystal (PDLC) films\nwere\nprepared by using acrylate monomers containing heteroatom-terminated\ngroups. The microscopic morphology and electro-optical properties\nreveal that these monomers effectively reduce the switching voltage\nand improve the contrast ratio at the same time. The saturation voltage\nof the best sample was reduced by 47%, and the contrast ratio was\nimproved by 74%. In addition, the introduction of various heteroatoms\nendows the PDLC films with a variety of functionalities. Sulfur atoms\neffectively increase the refractive index of the polymer matrix (<i>n</i><sub>p</sub>). By adjustment of the match between <i>n</i><sub>p</sub> and the ordinary refractive index of the LC,\nfilms with large contrast ratio and diminutive switching voltage were\nmanufactured for display applications. Besides, chlorine atoms can\nhelp reduce the surface anchoring energy of the polymer matrix to\nLCs and reduce the impedance. Meanwhile, the abundant C–H,\nC–O, CO, and C–Cl groups endow the films with\nsolar modulation functions.