Monolayer behavior and BAM observaion of biphenyl liquid crystalline polysiloxane at the A/W interface

Monolayers of a chiral biphenyl liquid crystalline polysiloxane and its monomer have been studied by π–A isotherms and hysteresis measurements. Both of them can form monolayers at different temperatures. The molecular packing in the monolayers are temperature-dependent for the monomer but not for the polymer. The molecular orderings are dominated by the packing of the biphenyl mesogens. Metastable monolayers with different ordering and thickness of domains have been directly observed by Brewster Angle Microscopy (BAM) in monomer monolayers. Both of them show characteristics of rigid monolayers. A broken process of the monolayers can be observed during expansion.