【摘要】 使用新型Gemini表面活性剂C12-3-C12·2Br(BDP)和C12-3(OH)-C12·2Cl(BDHP)制备了两种有机膨润土BDP-Bt和BDHP-Bt,并通过FT-IR、XRD表征了其微观结构,探究了两种有机膨润土对苯酚的吸附特性。结果表明:随着p H值的增大,两种有机膨润土对苯酚的吸附效果提高;两者对苯酚的吸附符合拟二级动力学模型;吸附曲线符合Langumir吸附;有机膨润土BDHP-Bt对苯酚的吸附效果优于BDP-Bt,从分子设计角度提出了一种制备有机膨润土新思路;BDP-Bt和BDHP-Bt对苯酚的吸附热和吉布斯自由能都为负值,表明这两种有机膨润土对苯酚的吸附为自发的放热过程。更多还原

【Abstract】 Bentonite was modified by means of ion exchange with two Gemini surfactants(1, 3- bis(dodecyldimethylammonio)-propane dibromide(BDP) and 1, 3-bis(dodecyldimethylammonio)-2-hydroxypropane dichloride(BDHP)) respectively to prepare two organ- bentonites BDP-B and BDHP-Bt. The organ-bentonites were characterized by X-ray diffraction(XRD) and FT-IR spectroscopy. Then their adsorption ability of phenol from aqueous solutions was examined in terms of the p H value and contact time.The results show that the adsorption of phenol increases with of the increasing p H value. The adsorption kinetics was found to follow the pseudo- second- order kinetic model and the equilibrium data fitted the Langmuir and Temkin equations better than Freundlich equation for both BDP modified bentonite(BDPBt) and BDHP modified bentonite(BDHP-Bt). The results also show that BDHP-Bt containing one hydroxyl in the Gemini surfactant molecule was more effective than BDP-Bt for the sorption of phenol from aqueous solutions. Thus, a new idea was put forward for the selection of high efficient modified agent, i.e., hydroxyl-containing Gemini surfactants. The negative values of ΔG° and ΔH° obtained from thermodynamic study of adsorption process indicated the spontaneous and exothermic nature for the two organ- bentonites.更多还原