Effect of reaction temperature on grafting of γ-aminopropyl triethoxysilane (APTES) onto kaolinite
Effect of reaction temperature on grafting of γ-aminopropyl triethoxysilane (APTES) onto kaolinite
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DOI：
10.1016/j.clay.2012.04.006
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发表时间：
2012-07
影响因子：
5.6
通讯作者：
Shu-qin Yang;P. Yuan;Hongping He;Zonghua Qin;Qing Zhou;Jianxi Zhu;Dong Liu
中科院分区：
文献类型：
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作者：
Shu-qin Yang;P. Yuan;Hongping He;Zonghua Qin;Qing Zhou;Jianxi Zhu;Dong Liu
采用傅里叶变换红外光谱、X射线衍射、热分析和元素分析等方法研究了温度（175、185、195和220°C）对γ-氨丙基三乙氧基硅烷（APTES）在二甲基亚砜（DMSO）预插层高岭土层间羟基上接枝的影响。在220°C下制备的APTES改性高岭土具有高含量APTES和高热稳定性的结构，其中APTES分子接枝到高岭土的内表面羟基上，并以交联单分子膜的形式排列。在175、185和195°C下制备的APTES改性高岭土表现出不均匀的层间结构，具有由接枝的APTES分子和与单层排列共存的氢结合的DMSO或APTES分子组成的伪双层排列。APTES的单层排列对应于约1.00nm的基底间距和1.73-1.89nm的伪双层排列。反应温度的升高有利于APTES分子与DMSO分子在高岭石层间的交换，以及氢键结合的APTES分子向接枝分子的转化，从而有利于形成单分子层结构。
The effect of the temperature (175, 185, 195 and 220°C) on the grafting of γ-aminopropyl triethoxysilane (APTES) on the interlayer hydroxyl groups of kaolinite pre-intercalated with DMSO were investigated using Fourier transform infrared spectroscopy, X-ray diffraction, thermal analysis and elemental analysis. The APTES-modified kaolinite prepared at 220°C showed a structure with high content of APTES and high thermal stability, in which the APTES molecules were grafted on to the inner-surface hydroxyl groups of kaolinite and arranged in the form of cross-linked monolayers. The APTES-modified kaolinites prepared at 175, 185 and 195°C exhibited inhomogeneous interlayer structure with pseudo-bilayer arrangements composed of grafted APTES molecules and hydrogen-bound DMSO or APTES molecules coexisting with monolayer arrangements. The monolayer arrangement of APTES corresponded to the basal spacing of about 1.00nm and the pseudo-bilayer arrangement 1.73–1.89nm. High reaction temperature was advantageous to the formation of the monolayer arrangement by promoting the exchange of the DMSO molecules by APTES molecules in the interlayer space of kaolinite, as well as the transformation of hydrogen-bound APTES molecules into grafted molecules.