阳离子表面活性剂对钠基蒙脱土的插层改性研究

摘要

Sodium-montmorillonite (Na+-MMT) was intercalation modified with octadecyl trimethyl ammonium chloride (OTAC) in aqueous suspension via an ion exchange mechanism.Fourier transform infrared spectroscopy (FTIR) study indicates that OTAC is successfully intercalated into Na+-MMT layers and/or adsorbed on the surface of Na+-MMT.X-ray diffraction (XRD) analysis revealed that the interlayer spacing of the Na+-MMT was extended with the content of OTAC increasing,and the maximum spacing can reach about 3.80 nm.Results of scanning electron microscopy (SEM) analysis reveals the morphologies change from soherical-like particles to high-aspect ratio flakes after modification.Different configurations of OTA+ chains within MMT interlayer are proposed based on the above analysis.The results of contact angle and the dispersion analysis show that the surface wettability of Na+-MMT is converted from hydrophilic to organophilic.%用十八烷基三甲基氯化铵(OTAC)通过离子交换法对钠基蒙脱土成功进行了有机化插层改性.红外分析结果表明:OTAC与蒙脱土之间发生了反应,X射线衍射(XRD)分析结果显示随OTAC浓度的提高,蒙脱上的(001)晶面间距逐渐扩大,最大值可增至3.80nm;基于以上分析研究,假定了OTAC分子在蒙脱土片层间的排列分布状态.扫描电镜(SEM)观察到改性前后蒙脱土的表面形貌发生了显著变化,改性前蒙脱土团聚成大小不一的致密堆积颗粒,而改性后的蒙脱土被剥离为松散的鱼鳞片状；接触角测试和沉降实验结果表明,改性后钠基蒙脱土的表面润湿性由亲水性转变为亲油性.