화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals, Vol.587, No.1, 60-79, 2013
Characterization of Hydrogen Bonded Liquid Crystals Formed by Suberic Acid and Alkyl Benzoic Acids
An inter hydrogen bonded homologous series with seven liquid crystalline complexes has been isolated and characterized. Double complementary hydrogen bonds are formed between a nonmesogen suberic acid (SA) and mesogenic p-n-alkyl benzoic acid (nBA); the series is referred as SA + nBA. Hydrogen bond is evinced by FTIR studies, while the mesogenic phases are identified by polarizing optical microscopic studies that are further substantiated by differential scanning calorimetry. Phase diagram is composed of nematic, smectic C, smectic F, and smectic G phases. The variation of tilt angle of various homologues with temperature in smectic C is fitted to a power law and the exponent value () is found to be in agreement with mean field predicted value (0.5). Orders of the various phase transitions are established by Cox method. Dielectric studies enable to identify phases and evaluate relaxation processes in smectic C and the corresponding activation energy is derived from the data.