Use of Anisotropic Materials as Chemical Detectors

Abstract

Abstract The visual detection between crossed polarizers, of organic vapors on various liquid crystal films is reported. Non-selective detection is achieved in the ppm range. However, opportunities exist for bettering selectivity and sensitivity as illustrated with a combined polymer-liquid crystal detection system for amines. Also described is the detection of liquid droplets by utilizing changes in the birefringence of polycarbonate membrane filters.