EFFECT OF TEMPERATURE ON AGGREGATION STRUCTURE OF LB FILM

Molecular assembly of polymerizable amphiphile ([2-(acryloyloxy)ethyl][10-[N-[1,3-bis(hexadecyloxy-carbonyl)propyl]carbanoyl]decyl]dimethylammonium bromide, designated as dihexadecyl N-[11-[[2-(acryloyloxy)eth-yl]dimethylammonio]undecanoyl]glutamate bromide, 2C-16-L-Glu-C11N+Ac) in the LB film was investigated in the temperature range above and below of the crystal-liquid crystal phase transition on the basis of wide-angle X-ray diffraction measurements. The crystal-liquid crystal phase transition temperature, T(c) was determined to be 323 k based on differential scanning calorimetry (DSC). The LB film was in the form of highly oriented bilayer lamella and hexagonally assembled cylinder (rod) structure below and above T(c) of the LB film, respectively. The hexagonally assembled cylinder structure above T(c) may be formed due to the reason why a hydrophobic part occupies much larger cross-sectional area in comparison with that of a hydrophilic part above T(c). The change of bilayer lamella-hexagonally assembled cylinder was thermally reversible beyond T(c).