Effect of preparation method on PDLC morphology and properties

摘要

The effect of preparation method and properties of components on the polymer-dispersed liquid crystal (PDLC) composite morphology is described. Three different methods of PDLC preparation - encapsulation, solvent-induced phase separation and photopolymerization-induced phase separation have been studied. Especially designed nematic and chiral nematic mixtures have been used as liquid crystal (LC) materials fulfilling requirements for mutual solubility and refractive index matching of composite components. In all cases the effect of LC concentration and the rate of solidification of polymer binder has been analyzed. It has been confirmed that the mean size of LC droplets is approximately proportional to the LC concentration and inversely proportional to solidification rate. The shape of droplets is usually close to spherical but using special methods one can obtain ellipsoidal droplets. The effect of morphology on electro- and thermooptical properties of obtained PDLC systems has been studied. The correlation between PDLC morphology and possible applications is discussed.