화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals, Vol.626, No.1, 193-206, 2016
Investigations on Hydrogen-Bonded Liquid Crystals Formed by P-N Alkyl Benzoic Acids and Dodecane Dicarboxylic Acids
A novel homologous series of hydrogen-bonded liquid crystals (HBLC) have been investigated. These Hydrogen bonds are formed between p-n dodecane dicarboxylic acid (DDC) and various p-n-alkyl benzoic acids (nBA), the present homologous series is referred as DDC + nBA. Seven complexes formed in the present homologous series are characterized by Fourier Transform Infrared spectroscopy (FTIR), Polarizing Optical Microscopy (POM) and Differential Scanning Calorimetry (DSC). Hydrogen bond formation is confirmed by FTIR. Textures observed in DDC + nBA are compared with the standard textures for phase identification. Characteristic phase like nematic, smectic F and smectic G are identified. Odd-even effect is observed in phase transition temperatures and corresponding enthalpy values at isotropic to nematic phase. Phase diagram is constructed from POM and DSC data. The effect of oxygen is discussed with respect to DDC + nBA and DDC + nOBA series. Quantitative treatment for the phase growth is discussed. Light filtering action at various temperatures in nematic phase is also studied.