地质聚合物原位制备NaA沸石分子筛和GMS-CdS光催化材料的研究
发布时间：2018-08-07 17:44
【摘要】：“地质聚合物”这一概念最早是由法国科学家Joseph Davidovits在1978年的国际理论和应用化学联合会(IU PAC)大分子会议上提出。Joseph Davidovits用质量比为1：1的高岭土和石英与固体氢氧化钠以及去离子水混合均匀经进一步的缩聚反应形成一种新型的无机聚合物材料。本实验首先采用溶胶-凝胶法制备出了Al2O3-SiO2粉体,并根据NaA沸石分子筛的理论配比采用0.9模的水玻璃(Na2O·0.9SiO2)制备出了Na2O-Al2O3-SiO2-nH2O地质聚合物浆料,通过调节不同的晶化条件来研究地质聚合物转化NaA沸石分子筛的效果。在研究非水热法制备NaA沸石分子筛时发现水分在其转化过程中起了很大的作用。本文又进行实验研究了水分在地质聚合物转化NaA沸石分子筛中的作用。根据地质聚合物的高温快速凝固机理,通过悬浮固化法制备出了地质聚合物小球(GMS),并经过离子交换和范德华力的作用吸附上Cd2+,通过光化学法使CdS生长在地质聚合物小球的表面,制备出的负载CdS的地质聚合物小球(GMS-CdS)。最后经光催化降解甲基橙来测试其光催化性能,本实验的主要结论如下：(1)地质聚合物非水热制备NaA沸石分子筛,这种方法不需要水热过程。在60℃下养护后,组成为1.11Na2O-Al2O3-2SiO2的地质聚合物能够转化为结晶良好的NaA沸石分子筛。地质聚合物凝胶转化法的条件如下：1)高浓度铝酸盐和硅酸盐的溶出,2)硅酸钠模数低于1大于0.8,3)Si/Al/Na摩尔比接近1：1：1。(2)当地质聚合物中的水分含量达到可以转化NaA沸石分子筛所需要的水分时,其转化的条件将会低于水热反应。如果将此地质聚合物放在自然状态下则其不会有晶相生成。密封条件下所需转化条件降低,这是由于水分子在狭小的空间里会更加活跃,水合钠离子的移动将会更加剧烈,提供地质聚合物晶化所需的养分更加充足。由于在养护过程中水分的损失,自然条件下的地质聚合物晶化所需营养物质无法被运输到结晶位置,进而影响了晶化过程。(3)通过范德华力和离子交换,镉离子能够与地质聚合物小球相结合。CdS颗粒通过光化学生长作用能够很容易地生长在地质聚合物小球上并形成黄色的负载CdS的地质聚合物小球。由于在降解过程中的协同作用,负载CdS的地质聚合物小球在降解甲基橙的过程中显示了极好的性能,降解效率达到了90.57%。负载CdS的地质聚合物小球降解甲基橙的动力学分析表明此过程符合二级动力学方程。
[Abstract]:The concept of "geopolymers" was first proposed by French scientist Joseph Davidovits at the (IU PAC) macromolecular conference of the International Union of theoretical and Applied Chemistry in 1978. Joseph Davidovits used kaolin and quartz with a mass ratio of 1:1 to solid hydrogen and oxygen. A new inorganic polymer material was prepared by further Polycondensation of sodium and deionized water. In this experiment, Al2O3-SiO2 powder was prepared by sol-gel method. According to the theoretical ratio of NaA zeolite molecular sieve, Na2O-Al2O3-SiO2-nH2O geopolymer slurry was prepared by 0.9 mode sodium silicate (Na2O 0.9SiO2). The effect of geopolymers on NaA zeolite was studied by adjusting different crystallization conditions. It is found that water plays an important role in the conversion process of NaA zeolites by non-hydrothermal method. The effect of water on the transformation of geopolymer into NaA zeolite was also studied experimentally. According to the mechanism of high temperature rapid solidification of geopolymers, the geopolymer ball (GMS), was prepared by suspension curing method and adsorbed on Cd2 by ion exchange and van der Waals force. CdS was grown on the surface of geopolymer spheres by photochemical method, and the geopolymer spheres (GMS-CdS) loaded with CdS were prepared. Finally, the photocatalytic properties of methyl orange were tested by photocatalytic degradation. The main conclusions of this experiment were as follows: (1) the geopolymers prepared NaA zeolites without hydrothermal process. After curing at 60 鈩，
本文编号：2170838
[Abstract]:The concept of "geopolymers" was first proposed by French scientist Joseph Davidovits at the (IU PAC) macromolecular conference of the International Union of theoretical and Applied Chemistry in 1978. Joseph Davidovits used kaolin and quartz with a mass ratio of 1:1 to solid hydrogen and oxygen. A new inorganic polymer material was prepared by further Polycondensation of sodium and deionized water. In this experiment, Al2O3-SiO2 powder was prepared by sol-gel method. According to the theoretical ratio of NaA zeolite molecular sieve, Na2O-Al2O3-SiO2-nH2O geopolymer slurry was prepared by 0.9 mode sodium silicate (Na2O 0.9SiO2). The effect of geopolymers on NaA zeolite was studied by adjusting different crystallization conditions. It is found that water plays an important role in the conversion process of NaA zeolites by non-hydrothermal method. The effect of water on the transformation of geopolymer into NaA zeolite was also studied experimentally. According to the mechanism of high temperature rapid solidification of geopolymers, the geopolymer ball (GMS), was prepared by suspension curing method and adsorbed on Cd2 by ion exchange and van der Waals force. CdS was grown on the surface of geopolymer spheres by photochemical method, and the geopolymer spheres (GMS-CdS) loaded with CdS were prepared. Finally, the photocatalytic properties of methyl orange were tested by photocatalytic degradation. The main conclusions of this experiment were as follows: (1) the geopolymers prepared NaA zeolites without hydrothermal process. After curing at 60 鈩，
本文编号：2170838
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