A FT-IR Spectroscopic Study on Conformation of the Hydrocarbon Chains of Crystallized Cetyltrimethylammonium Bromide

The conformations of the hydracarbon chain of crystallized cetyltrimethylammonium bromide have been studied by FT-IR spectroscopy in the temperature range from 290 to 400K. The results show that the crystal undergoes a long process of transition from structural order to disorder. At room temperature, the hyderocarbon chains are packed in parallel each other with all-trans conformation expect a few TG defects. At the temperature above 343K, A few GTG’ defects are generated and the interaction between chains is weakened. At the tempcrature above 373K, the highly distored GTG and GG defects appear and the number of the TG and GTG’defects increases, meantimes, the linearity of the chain axis is destoried substantially.