Comparative studies of polymer-dispersed liquid crystal films via a thiol-ene click reaction

In this work, the thiol-ene click reaction is employed to fabricate polymer-dispersed liquid crystal (PDLC) films by photoinitiated polymerization. The PDLC films are prepared by systematic variation of key conditions: variety and content of -ene monomer, liquid crystal (LC) content, curing time, and curing light intensity. We find that both the morphologies and electro-optic properties of these films are adjustable. When increasing the length of alkyl main chain of -ene monomers, the driving voltages reduce, but in turn, the contrast ratio decreases. Increasing -ene monomer content raises the driving voltages as well as the response time, and the increase of LC content lowers the driving voltages but has a negative effect on the contrast ratio. The changes to the curing conditions (both curing time and UV light intensity) can be used to modify the driving voltages, response time, and contrast ratios of PDLC films. These comparative studies will elucidate new insights in commercial applications of intelligent PDLC films.