Journal of Polymer Science Part B: Polymer Physics, Vol.38, No.7, 980-986, 2000
Textures and disclinations in the cholesteric liquid-crystalline phase of a cyanoethyl chitosan solution
Disclinations in the fingerprint-like cholesteric texture of a natural polymer derivative, cyanoethyl chitosan, were observed and studied by both polarizing optical microscopy and scanning electron microscopy. In the latter technique, permanganic etching was developed for this cholesteric texture to increase the contrast. A special mechanism for cholesteric phase etching is suggested and discussed. Some chi, lambda, and tau disclinations and domain walls were observed.
Keywords:chitosan/cyanoethyl chitosan/cholesteric liquid crystal;texture defect;disclination;chemical etching