Studies of polymer ball type polymer dispersed liquid crystal films

Abstract

‘Reverse’ or ‘polymer ball’ polymer dispersed liquid crystal (PDLC) samples were prepared by a photopolymerization induced phase separation method. A detailed study of the effects of the sample preparation parameters, such as curing time, curing intensity, and liquid crystal concentration are reported. It was found that by adjusting these parameters, we were able to change the morphology of these ‘polymer ball’ PDLC samples and thus change their optical characteristics. Incomplete polymerization of the PDLC samples results in a higher threshold voltage and a lower ON state transmission. When the amount of monomer is too low, the shape of the resulting polymer ball becomes irregular, and the sample has a larger threshold voltage and a larger saturation voltage.