Clean production of CTAB-montmorillonite: formation mechanism and swelling behavior in xylene
Clean production of CTAB-montmorillonite: formation mechanism and swelling behavior in xylene
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CTAB-蒙脱石的清洁生产：形成机理及在二甲苯中的溶胀行为
DOI：
10.1016/j.clay.2014.06.007
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发表时间：
2014-08
影响因子：
5.6
通讯作者：
WANG Hao
中科院分区：
文献类型：
--
作者：
YU Wei Hua;REN Qian Qian;TONG Dong Shen;ZHOU Chun Hui;WANG Hao
成功制备了在二甲苯等疏水介质中具有高溶胀性的有机蒙脱石（OMt）。该过程是通过用分散在极少量水和乙醇中的十六烷基三甲基溴化铵 (CTAB) 对 Ca2+-蒙脱石 (Ca2+-Mt) 进行清洁、简单的改性来实现的。在此过程中，不需要Na+交换反应和洗涤步骤。研究了OMt的形成机制及其在二甲苯中的溶胀性。通过洗涤和未洗涤的 OMt 的热重 (TG) 和差热重分析 (DTG) 测定了所得 OMt 产品中吸附在层间空间中的十六烷基三甲基铵 (CTA+) 阳离子和 CTAB 分子、吸附在外表面上的 CTAB 分子和游离 CTAB 分子的分布。从粉末X射线衍射(XRD)图和傅里叶变换红外(FT-IR)光谱推导出CTA+阳离子在层间空间的排列模型。结果表明，吸附在OMt层间空间的CTA+阳离子和CTAB分子以及吸附在OMt外表面的CTAB分子通过离子交换、疏水相互作用和范德华力对Ca2+-Mt的修饰发挥了作用。在制备混合物中添加乙醇有利于在OMt的层间空间结合更多的CTA+阳离子和CTAB分子，并增强粘土颗粒的分散。 OMt 样品在二甲苯中的胶体产率最高为 64.0%，高于多步工艺生产的商业 OMt。 OMt在二甲苯中形成良好的凝胶状结构取决于CTAB分子和CTA+阳离子在OMt内外表面的适当分布、CTA+阳离子在OMt层间空间的有序排列以及分散的OMt颗粒的小尺寸。二甲苯中大量 OMt 颗粒网络是通过相邻 Mt 颗粒之间的边对边、面对面和面对面连接以及多面连接形成的。
Organo-montmorillonite (OMt) with high swellability in a hydrophobic medium such as xylene was successfully prepared. The process was realized by clean and simple modification of Ca2 +-montmorillonite (Ca2 +-Mt) with cetyltrimethylammonium bromide (CTAB) dispersed in very small amounts of water and ethanol. In the process, there were no needs for the steps of a Na+-exchange reaction and washing. The mechanisms of formation of OMt and its swellability in xylene were investigated. The distribution of cetyltrimethylammonium (CTA+) cations and CTAB molecules adsorbed in the interlayer spaces, CTAB molecules adsorbed on the external surfaces and free CTAB molecules in the resultant OMt products was determined by the thermogravimetric (TG) and differential thermogravimetry (DTG) of the washed and unwashed OMt. The arrangement models of CTA+cations in the interlayer spaces were deduced from powder X-ray diffraction (XRD) patterns and Fourier transform infrared (FT-IR) spectra. The results suggested that CTA+cations and CTAB molecules adsorbed in the interlayer spaces and CTAB molecules adsorbed on the external surfaces of OMt played a role in the modification of Ca2 +-Mt by ion exchange, hydrophobic interactions and van der Waals forces. Addition of ethanol into the preparation mixture was favorable for binding more CTA+cations and CTAB molecules in the interlayer spaces of OMt and enhanced dispersion of clay particles. A maximal 64.0% colloid yield in xylene for the OMt sample, which was higher than that of the commercial OMt produced by a multistep process, was achieved. The formation of good gel-like structure of OMt in xylene depended on proper distribution of CTAB molecules and CTA+cations on the external and internal surfaces of OMt, ordered arrangements of CTA+cations in the interlayer spaces of OMt and the small sizes of dispersed OMt particles. A large volume of the networks of OMt particles in xylene was formed by edge-to-edge, face-to-face and face-to-edge between neighboring Mt particles and multifacial linking.
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影响因子：
9.9
作者：
Runliang Zhu;Tong Wang;Fei Ge;Wangxiang Chen;Zhimin You
通讯作者：
Runliang Zhu;Tong Wang;Fei Ge;Wangxiang Chen;Zhimin You
影响因子：
12.1
作者：
L. Wu;C. Zhou;J. Keeling;D. Tong;W. Yu
通讯作者：
L. Wu;C. Zhou;J. Keeling;D. Tong;W. Yu
影响因子：
5.6
作者：
Z. Mojović;P. Banković;A. Milutinović-Nikolić;B. Nedić;D. Jovanović
通讯作者：
Z. Mojović;P. Banković;A. Milutinović-Nikolić;B. Nedić;D. Jovanović
影响因子：
5.6
作者：
B. Riebe;S. Dultz;C. Bunnenberg
通讯作者：
B. Riebe;S. Dultz;C. Bunnenberg
影响因子：
5.6
作者：
Heng-yu Zhao;C. Zhou;L. Wu;Jianqiu Lou;Na Li;Huimin Yang;D. Tong;W. Yu
通讯作者：
Heng-yu Zhao;C. Zhou;L. Wu;Jianqiu Lou;Na Li;Huimin Yang;D. Tong;W. Yu