Gemini表面活性剂改性蒙脱土的制备及其对水中苯酚的吸附

以3种Gemini表面活性剂(n=14,16,18)和常见的表面活性剂十六烷基三甲基溴化铵(CTAB)对钠基蒙脱土进行了有机改性.红外光谱、X射线衍射、热重分析表明,表面活性剂已成功插入蒙脱土片层间.X射线衍射结果显示,Gemini表面活性剂比CTAB表现出更强的插层能力,经CTAB,Gemini 1,Gemini 2,Gemini 3四种表面活性剂改性后,蒙脱土的面间距d001分别为2.18,3.25,3.83,3.84nm,且随着Gemini表面活性剂碳链的增长,蒙脱土的层间距增大.紫外可见光谱分析结果表明,用Gemini表面活性剂改性的蒙脱土明显比CTAB改性的蒙脱土对苯酚的吸附量大,在相同条件下,CTAB改性的蒙脱土对苯酚的吸收率为7.29%,三种Gemini表面活性剂改性的蒙脱土对苯酚的吸收率分别为41.16%,56.28%和65.14%,表明随着Gemini表面活性剂的碳链的增长,对苯酚的吸附量也相应增加.

Preparation of Montmorillonites Modified with Gemini Surfactant and their Adsorption of Phenol in Water

Three kinds of Gemini surfactants(n=14,16,18) and a common surfactant cetyltrimethylammonium bromide(CTAB) were used to modify the sodium montmorillonite(MMT).Infrared spectroscopy,X-ray diffraction,and thermogravimetric analysis show that surfactants have been successfully inserted between the MMT layers.Further,X-ray diffraction shows that Gemini surfactants have greater intercalation ability than CTAB,the d001 spacing of the montmorillonite which modified by CTAB,Gemini 1,Gemini 2,Gemini 3 were 2.18,3.25,3.83,3.84 nm,and with the carbon chain of Gemini surfactants growth,the layer spacing of the sodium montmorillonite will also increases.UV-Vis spectrophotometer result shows that the montmorillonite modified by Gemini surfactants significantly absorb more phenol than the montmorillonite modified by CTAB.Under the same conditions,the absorption rates of phenol of the montmorillonite modified by CTAB,Gemini 1,Gemini 2,Gemini 3 were 7.29%,41.16%,56.28%,65.14%,and with the carbon chain of Gemini surfactants grows,more phenol will be absorbed.