Effect of surfactant concentration on the stacking modes of organo-silylated layered double hydroxides
Effect of surfactant concentration on the stacking modes of organo-silylated layered double hydroxides
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DOI：
10.1016/j.clay.2009.06.007
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发表时间：
2009-08
影响因子：
5.6
通讯作者：
Q. Tao;Jie Yuan;R. Frost;Hongping He;P. Yuan;Jianxi Zhu
中科院分区：
文献类型：
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作者：
Q. Tao;Jie Yuan;R. Frost;Hongping He;P. Yuan;Jianxi Zhu
研究了表面活性剂浓度对硅烷基化水滑石的结构、形貌和热性能的影响。采用原位共沉淀法，用3-氨丙基三乙氧基硅烷（APTS）和阴离子表面活性剂十二烷基硫酸钠（SDS）对水滑石（LDHs）进行表面改性。通过X射线衍射（XRD）检测到所得材料中存在两种不同的堆积模式。一种是具有相同结构的LDH，其中SDS和APTS仅结合于LDH的外表面和板边缘。二是层间距增大，SDS和APTS与LDH内表面结合。随着SDS和APTS负载量的增加，改性LDH的表面出现粗糙的透射电子显微镜（TEM）图像中观察到。对硅烷基化水滑石的衰减全反射傅里叶变换红外（ATR FTIR）光谱进行了表征，结果表明，APTS成功地接枝到了LDH上，并出现了一系列归属于-NH 2和Si-O-M（M=Mg和Al）的吸收峰。热重曲线（TG）表明，硅烷接枝后的样品具有较少的-OH浓度和较少的层间水，这是由于Si-OH与LDH表面-OH发生缩合反应消耗了-OH。这些纳米材料具有潜在的应用前景，包括粘土基纳米复合材料、去除水中有机污染物的吸附剂和阻燃材料。
The effects of the surfactant concentration on the structure, morphology and thermal property of silylated hydrotalcites have been investigated. By in-situ coprecipitation, the surfaces of layered double hydroxides (LDHs) have been modified by using 3-aminopropyltriethoxysilane (APTS) and anionic surfactant, Na-dodecylsulfate (SDS). Two different stacking modes in the resultant materials were detected by X-ray diffraction (XRD). One has an identical structure of LDHs, in which the SDS and APTS only bond to the outside surfaces and plate edges of LDH. The other is with enlarged interlayer distance, in which SDS and APTS combined with the inside surfaces of LDH. With the increased loading of SDS and APTS, the surface of the modified LDH appeared rough as observed in the transmission electron microscopy (TEM) images. The attenuated total reflection Fourier-transform infrared (ATR FTIR) spectra of the silylated hydrotalcites showed a series of bands attributed to –NH2and Si–O–M (M=Mg and Al), proving that APTS has successfully been grafted onto LDH. The thermogravimetric curves (TG) showed that the silane grafted samples have less –OH concentration and less interlayer water, as a result of the –OH consumption during the condensation reaction between Si–OH and –OH on LDH surface. These nanomaterials are of potential applications including clay-based nanocomposites, adsorbents for removal of organic contaminants from water and flame retardant materials.