Phase Behavior of Nematic-Nonnematic Binary Systems (III) : Effects of Hydrogen Bonding

Abstract

Binary mixtures of nematic 5CB with some kinds of non-nematic solutes were found to cause the increase in nematic-isotropic transition temperature, contrary to usually observed decrease. All these 'unusual' solutes found in this work had active hydrogen which can act as hydrogen bond donor. 'Unusual' increase in the clearing temperature was attributed to the hydrogen bonding interaction between 5CB and solutes. The thermal and spectroscopic effects of hydrogen bonding interaction between 5CB and various non-nematic solutes were studied in detail.