Transmittance behavior of nematic E48:polyvinylpyrrolidone (PVP) polymer di
spersed liquid crystals (PDLC) is investigated in relation to the liquid cr
ystals to polymer ratio. Five E48:PVP concentration mixtures are prepared:
75:25, 77.5:22.5, 80:20, 82.5:17.5, and 85:15. Solvent Induced Phase Separa
tion and Thermally Induced Phase Separation techniques are used. Droplet si
zes are measured using a polarizing microscope, and the 80:20 mixture prepa
red by slow cooling is determined to have the largest droplets. The liquid
crystal cells prepared by fast cooling needed a higher switching voltage (r
anging from 7V-35V) while the switching voltage of slow-cooled samples vari
ed from 6V-47V, with most of the samples having switching voltages close to
10V. The transmittance behavior and contrast ratio of PDLC's are then inve
stigated with a 660-680 nm light source. It is observed that fast-cooled sa
mples had higher contrast ratios compared to slow cooled samples. Photograp
hs of each sample are acquired to determine their respective textures.