Abstract: Organic bentonite was prepared from purified Na-bentonite using hexadecyl trimethyl ammonium chloride (CTAC) as modifier.Influence of mix ratio of reactants,reaction temperature,and reaction time on the performace of organic bentonite were studied and the optimal modification conditions were obtained as follows:mix ratio of modifier and Na-bentonite was 115 mmol/100 g,reaction temperature was 60 ℃,and reaction time was 90 min.Modification effect of organic bentonite was characterized by FT-IR and XRD.Results showed that organic quaternary ammonium could enter the interlayers of bentonite easily and increase the layer distance without destroying the structure of it.Therefore,excellent organic bentonite can be prepared by using of CTAC as the modifier.

Key words: bentonite, hexadecyl trimethyl ammonium chloride, modification, exchange rate