硅基气凝胶块体材料的常压可控合成及其对重金属铅离子吸附性能研究

发布时间：2018-06-05 22:22

本文选题：常压干燥 + 块状　；参考：《江苏大学》2017年硕士论文

【摘要】：二氧化硅气凝胶的独特且优越的性能使得科研工作者们进行了广泛且深入的研究,特别是在如何使用简便且有效的方法制备出块状的气凝胶方面,做了许多研究工作。本论文在前人的工作基础上,使用了常压干燥的方式,进行了些许改进和延伸工作,其主要研究内容如下三个方面所示;(1)采用共硅源的方式,溶胶-凝胶法制备出含有氨基的湿凝胶,通过三种不同种类的二异氰酸酯对湿凝胶进行交联,选用常压条件下干燥的方式。在制备过程中,通过控制氨基的引入量,使得交联过后的硅基气凝胶仍然含有大量的氨基基团,而氨基将会对吸附废水中的Pb~(2+)起到促进作用。在制备过程中无需复杂且冗长的溶剂交换和表面改性的过程,制备周期较短,通过对引入的化学基团的控制使得其作为吸附材料有着较好的吸附效果。(2)异氰酸酯和氨基形成的聚合物和在溶胶-凝胶过程中添加的阴离子表面活性剂SDS起到了双模板的作用,选用常压的干燥方式制备出具有较为均匀孔径的块状二氧化硅气凝胶。添加一定浓度的阴离子表面活性剂(SDS)与氨基基团的静电吸引作用能够形成胶束,从而能够在溶胶-凝胶的过程中有效地占据孔洞位置,并通过使用六亚甲基二异氰酸酯在湿凝胶骨架外层形成一层均匀的聚合物模板来对骨架强度增强。通过高温煅烧,同时移除表面活性剂模板和聚合物模板,从而得到具有均匀孔洞结构的块状硅基气凝胶,通过实验室的模拟吸附实验证明其作为吸附材料对废水中的Pb~(2+)有着较好的吸附效果。(3)在常压的条件下,采用聚合物分解和用硅氧烷对传统的甲醛-苯酚有机气凝胶进行复合这俩种方法,在常压条件下制备出了块状的硅炭复合气凝胶,然后对这俩种不同的硅炭复合气凝胶做了较为详尽的表征和分析,其性能同单一的块状硅基气凝胶相比较而言有着较大的提高。同时,对俩种不同的方法制备的硅炭复合气凝胶进行模拟吸附含有Pb~(2+)废水的实验表明,制备的硅炭复合气凝胶有着较好的吸附效果。
[Abstract]:Because of the unique and superior properties of silica aerogels, researchers have carried out extensive and in-depth research, especially in the preparation of bulk aerogels using simple and effective methods, which have done a lot of research work. On the basis of the previous work, this paper uses the atmospheric pressure drying method to do some improvement and extension work. The main research contents are as follows: 1) the common silicon source is adopted. The wet gel containing amino group was prepared by sol-gel method. The wet gel was crosslinked by three kinds of diisocyanate and dried under normal pressure. In the preparation process, by controlling the amount of amino introduced, the cross-linked silicon-based aerogels still contain a large number of amino groups, and amino groups will promote the adsorption of Pb~(2 in wastewater. There is no need for complex and lengthy processes of solvent exchange and surface modification in the preparation process, and the preparation period is relatively short. By controlling the chemical groups introduced, the isocyanate and amino polymers and the anionic surfactant SDS added in the sol-gel process act as double templates for the adsorption of isocyanate and amino groups. Bulk silica aerogels with uniform pore size were prepared by atmospheric pressure drying. Adding a certain concentration of anionic surfactant (SDS) to the electrostatic attraction of the amino group can form a micelle, which can effectively occupy the pore position in the sol-gel process. By using hexamethylene diisocyanate to form a uniform polymer template in the outer layer of the wet gel framework, the skeleton strength was enhanced. The bulk silicon-based aerogels with uniform pore structure were obtained by calcining at high temperature and removing both surfactant and polymer templates at the same time. The simulated adsorption experiments in the laboratory show that the adsorbed material has a better adsorption effect on Pb~(2 in waste water under atmospheric pressure. Bulk silicon-carbon aerogels were prepared under atmospheric pressure by polymer decomposition and siloxane compounding of traditional formaldehyde-phenol aerogels. Then the two different silicon-carbon composite aerogels were characterized and analyzed in detail, and their properties were greatly improved compared with the single bulk silicon-based aerogels. At the same time, the simulated adsorption of silica / carbon aerogels containing Pb~(2) showed that the silica / carbon composite aerogels had a good adsorption effect.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;TQ427.26;O647.3

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