不同微环境有机蒙脱土的制备及吸附亚甲基蓝的研究

Preparation of Organic Montmorillonite with Different Microenvironments and study of Methylene Blue Adsorption

合成了一系列带不同官能团的表面活性剂并用其修饰蒙脱土(MMT).通过X射线衍射(XRD)和热重分析(TG)对所修饰的蒙脱土进行了表征,结果表明:成功地制备出了3种不同微环境的有机蒙脱土:胺基有机蒙脱土(MMT-12-N(CH3)2)、羟基有机蒙脱土(MMT-12-OH)和甲基有机蒙脱土(MMT-12-CH3).研究比较了溶液pH、接触时间和染料浓度对3种不同微环境的有机蒙脱土吸附亚甲基蓝(MB)的影响.结果表明:MMT-12-CH3的吸附量大且受pH影响最小,MMT-12-N(CH3)2和MMT-12-OH分别在5-9和5-8的pH范围也都有较好的吸附效果,吸附MB的动力学曲线都遵从假二级动力学模型,吸附等温线符合Langmuir模型,相同条件下,其吸附量大小依次为MMT-12-CH3>MMT-12-OH>MMT-12-N(CH3)2.

A series of surfactants with different functional groups were prepared and used as modifier for montmorillonite （MMT）.The modified montmorillonites were characterized by XRD and TG.The results showed that three different microenvironment organic montmorillonite which were MMT-12-N（CH3）2,MMT-12-OH and MMT-12-CH3 were successfully prepared.The effects of solution pH,contact time and dye concentration on the MB adsorption onto the three organic montmorillonite with different microenvironment were investigated.Results showed that adsorption capacity of MMT-12-CH3 was large and less influenced by the pH.MMT-12-N（CH3）2 and MMT-12-OH had better adsorption capacity in the pH range of 5-9 and 5-8 respectively.The adsorption of MB fitted pseudo-second-order kinetics,and the adsorption isotherm were consistent with the Langmuir model,under the same conditions while the order of adsorption capacities was：MMT-1 2-CH3 ＞ MMT-12-OH ＞ MMT-12-N （CH3） 2.