Investigation of thermodynamic properties of 4-decyloxybiphenyl-4′-carboxylic acid liquid crystal and preparation of polymer dispersed liquid crystal composite

Abstract In this study, firstly, retention behavior of solvents on the liquid crystalline material 4-decyloxybiphenyl-4′-carboxylic acid (DBCA) has been studied by inverse gas chromatography (IGC) technique. Liquid crystal (LC) selectivity was investigated using the acetate isomers by the IGC method at temperatures between 333.2 K and 543.2 K. Later on, the interactions of LC with n-octane, n-nonane, n-decane, undecane, dodecane, tridecane, n-propyl benzene, isopropyl benzene, ethylbenzene, chlorobenzene and toluene between 518.2 K and 543.2 K were examined. LC-solvent interaction parameters for Flory-Huggins theory, χ 12 ∞ , and equation of state theory, χ 12 ∗ , effective exchange energy parameters, X eff , the weight fraction activity coefficent, Ω 1 ∞ , the partial molar heat of mixing at infinite dilution of the solvent, ∆H 1 ∞ , molar heat of vaporization of solvent, ∆H V and the partial molar heat of sorption of the solvent, ∆H 1, s were obtained. Secondly, polymer dispersed liquid crystal (PDLC) composite film in composition 20/80 poly(methyl methacrylate) (PMMA):DBCA by weight was synthesized by solvent-induced phase separation method. The mesomorphic behavior of DBCA and PDLC composite has been investigated by differential scanning calorimetry (DSC) and optical polarizing microscopy (PM).