College of Environmental Science and Engineering, South China University of Technology, Guangzhou, Guangdong, PR China.
J Colloid Interface Sci. 2012 Mar 1;369(1):344-51. doi: 10.1016/j.jcis.2011.11.061. Epub 2011 Dec 4.
A hybrid organic-inorganic material based on vermiculite was prepared to remove diethyl phthalate (DEP) from aqueous solution. Natural vermiculite was activated with HCl to improve the specific surface area and was then modified by silanization using trimethylchlorosilane. Organovermiculite prepared by ion exchange with hexadecyl trimethylammonium bromide (HDTMAB) was also tested for comparison. The leaching of 2 mol L(-1) HCl at 80°C increased the specific surface area of vermiculite from 14.4 to 500.0m(2)g(-1), and the average pore-diameter was decreased from 7.90 nm to 2.75 nm. Fourier transform infrared spectroscopy (FTIR) spectra indicated that trimethysilyl groups were grafted covalently on the surface of acid vermiculites. The specific surface area of trimethylchlorosilane-modified acid vermiculites (TMAVs) (355.4 m(2) g(-1)) was much larger than that of organovermiculite (6.0 m(2) g(-1)). The isotherm adsorption experiments of DEP showed that TMAVs exhibited linear isotherms, suggesting that the uptake of DEP was controlled by partitioning mechanism. The maximal partition coefficient (K(d)) of TMAVs was 3.1 times higher than that of organovermiculite, implying that TMAVs had stronger organic affinity than organovermiculite. The results demonstrate that the adsorption capacity and mechanism of organoclays were controlled by the specific surface area and organic loading, whereas the length of alkyl chain of organic modifier was not the key factor.
一种基于蛭石的有机-无机杂化材料被制备出来，以从水溶液中去除邻苯二甲酸二乙酯（DEP）。天然蛭石先用 HCl 进行活化以提高比表面积，然后再用三甲基氯硅烷进行硅烷化改性。还用十六烷基三甲基溴化铵（HDTMAB）进行离子交换制备的有机蛭石进行了对比测试。在 80°C 下用 2 mol L(-1) HCl 浸出，将蛭石的比表面积从 14.4 增加到 500.0 m(2)g(-1)，平均孔径从 7.90nm 减小到 2.75nm。傅里叶变换红外光谱（FTIR）谱图表明三甲硅基基团通过共价键接枝到酸活化蛭石的表面。三甲基氯硅烷改性酸活化蛭石（TMAVs）的比表面积（355.4 m(2) g(-1)）远大于有机蛭石（6.0 m(2) g(-1)）。DEP 的等温吸附实验表明，TMAVs 呈现出线性等温线，表明 DEP 的摄取受分配机制控制。TMAVs 的最大分配系数（K(d)）比有机蛭石高 3.1 倍，这表明 TMAVs 比有机蛭石具有更强的有机亲和力。结果表明，有机黏土的吸附容量和机制受比表面积和有机负载控制，而有机改性剂的烷基链长度不是关键因素。
