PRECURSOR FILM OF A SPREADING DROP OF LIQUID-CRYSTAL

We present results of an ellipsometric investigation of spreading drops of nonvolatile 4'-n-pentyl-4-cyanobiphenyl liquid crystal on a smooth horizontal silicon wafer and on a fused silica plate. We observed the precursor film near the liquid-crystal drop. The precursor film is formed in our case when the liquid drop partially wets the solid substrate. Our experiments have shown that these precursor films have near-molecular thicknesses with the long axis of the molecules in the film being not randomly oriented.