Nematic Ordering in Polymer Dispersed Liquid Crystals

5 Nematic Ordering in Polymer Dispersed Liquid Crystals 

Real-time FTIR was used to study the curing of a UV-curable prepolymer (NOA65) and its mixtures with liquid crystals. Curing reactions were examined as a function of film thickness, temperature, and liquid 

Nematic ordering can be observed and quantified based on a change in a characteristic band of the liquid crystal. Moreover, the phase separation and the onset of nematic ordering can be temporarily resolved. The conversion at phase separation decreased strongly with an increase in liquid crystal content, while the conversion required for phase separation increased with increasing temperature. The fraction of liquid crystal present as nematic droplets and total fraction of nematic domains in NOA65 were quantified from changes in the vibrational spectrum of the liquid crystal (E7, which refers to the commercial label for the liquid crystal) (37). 

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