Polymer-Dispersed Liquid Crystal Films Studied by Near-Field Scanning Optical Microscopy

Topographic and near-field scanning optical microscopy images of nematic liquid crystalline (LC) droplets dispersed in polymer films are presented. It is conclusively shown that the topographic images provide information invaluable to a complete understanding of the droplet formation process, shape, and internal LC organization. The topographic data indicate that the droplets are encapsulated in a thin, relatively solid polymer shell. Many droplets in these films are observed to take on spheroidal and discoidal shapes. A new class of toroidal droplets, possibly formed by droplet rupture during film formation, is also observed and characterized. Polarization-dependent optical images are employed to determine the LC organization in these droplets.