Structure and thermal stability of organo-vermiculite
Structure and thermal stability of organo-vermiculite
复制标题
有机蛭石的结构和热稳定性
DOI：
10.1016/j.clay.2016.06.011
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发表时间：
2016-11
影响因子：
5.6
通讯作者：
Runliang Zhu
中科院分区：
文献类型：
--
作者：
Xiaoli Su;Lingya Ma;Jingming Wei;Runliang Zhu
以膨胀蛭石（EVrm）为原料，采用不同用量的表面活性剂（十六烷基三甲基溴化铵，HDTMAB）对膨胀蛭石进行改性，制备了有机蛭石（HEVrm）。采用X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和热重分析（TG）对所得HEVrm进行了表征。与文献报道的有机蒙脱土（OMt）的层间距逐渐增加不同，HEVrm的层间距呈一步增加。因此，表面活性剂嵌入EVrm的层间空间是不均匀的。在HDTMAB浓度较低时，表面活性剂只能插层部分EVrm层间空间;随着HDTMAB浓度的增加，插层空间越来越多，最终达到“饱和”状态。插层表面活性剂在层间空间内呈全反式构象的石蜡单分子层排列。插层表面活性剂在HEVrm中的分解温度与纯表面活性剂的分解温度非常相似。粘土矿物层对插层表面活性剂热稳定性的保护作用不明显，这与有机蒙脱土的热稳定性有很大不同。这可能是由于在具有相对大的层间高度的HEVrm中基底间距的一步增加。这些发现对HEVrm的制备和应用具有重要意义。
In this study, organo-vermiculites (HEVrm) were prepared by modifying expanded vermiculite (EVrm) with different amounts of surfactant (hexadecyltrimethyl ammonium bromide, HDTMAB). The obtained HEVrm were characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TG). Instead of a gradual increase of the basal spacing for organo-montmorillonite (OMt) as reported in literatures, a one-stepped increase of the basal spacing was observed for HEVrm. As such, the intercalation of surfactant into the interlayer space of EVrm is not homogeneous. In particular, only part of the interlayer spaces of EVrm were intercalated by surfactants at low HDTMAB concentration; with the increase of surfactant concentration, more and more interlayer spaces were intercalated, reaching a “saturation” state at last. The intercalated surfactant adopted a paraffin-monolayer arrangement withall-transconformation within the interlayer space. The decomposition temperature of the intercalated surfactant in HEVrm is very similar to that of neat surfactant. The protection of the clay mineral layers for the thermal stability of the intercalated surfactant is not obvious, which is very different from that for OMt. This may be due to the one-stepped increase of the basal spacing in HEVrm with relatively large interlayer height. These findings are of high importance for preparation and application of HEVrm.
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影响因子：
5.6
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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