阶层多孔二氧化硅块体材料的制备及其应用研究
发布时间：2018-10-22 10:10
【摘要】：阶层多孔二氧化硅(Si02)块体是一种大孔、介孔或微孔梯度分布的多孔材料,具有三维连贯大孔、精细介孔结构等孔道特征,因而拥有高比表面积、高吸附、高气孔率等特性,在分离、吸附、过滤、催化等重要领域具有广阔的应用前景。溶胶-凝胶伴随相分离法是制备阶层多孔Si02块体材料的有效途径,但目前制备流程需要高温后处理,且介孔结构无序,在修饰改性方面也存在工序复杂及使用有毒改性溶剂、还原剂等问题。本论文在综合论述了溶胶-凝胶伴随相分离制备阶层多孔块体材料的基础上,研究了大孔SiO2块体及阶层多孔Si02块体制备、多孔块体的环保表面改性及其银负载、CO2捕捉等内容,分析了溶胶-凝胶转化与相分离协同控制形成共连续大孔结构、棒状胶束模板形成有序介孔结构、氨基表面改性多孔骨架、乙二醇还原银离子等机理,为阶层多孔Si02块体材料在高效液相色谱分离、催化反应、CO2捕捉等领域应用奠定基础。主要研究内容及结果如下：(1)以正硅酸甲酯(TMOS)为前驱体、0.01 mol·L-1盐酸(HCL)为催化剂、聚环氧乙烷(PEO)为相分离剂、环氧丙烷(PO)为凝胶促进剂,采用溶胶-凝胶伴随相分离法制备具有三维连贯大孔,且比表面积418m2.g-1多孔Si02块体；在此基础上,引入造孔剂SDS制备阶层多孔Si02块体材料,大孔孔径为1-3μm,介孔孔径为4-5 nm,比表面积可达650m2·g-1。(2)以TMOS为前驱体、0.01 mol·L-1盐酸为催化剂、环氧丙烷(PO)为凝胶促进剂,以三嵌段共聚物聚氧乙烯-聚氧丙烯-聚氧乙烯(Pluronic P123)及三甲苯(TMB)为模板剂及膨胀剂,一步法直接制备兼具连续大孔骨架及有序介孔结构的阶层多孔Si02块体,大孔孔径为1-2μm,介孔孔径为10-11 nm,比表面积高达848m2·g-1,8000C热处理后仍能保持该阶层多孔结构稳定。(3)对制备的阶层多孔Si02进行相对无毒改性及银负载。3-氨丙基三乙氧基硅烷(APTES)作为改性剂,首次采用乙醇为改性溶剂,对其进行改性；首次采用乙二醇为还原剂,利用其还原性对改性后Si02进行银纳米颗粒负载,银负载率可达15.44wt.%。探究其改性及还原机理、银负载量影响因素,并提出通过适当温度热处理方法来提高银负载阶层多孔Si02块体的比表面积。(4)对制备的阶层多孔Si02进行氨基改性,考察氨基改性大孔及阶层多孔Si02块体材料的CO2吸附性能。测试表明：多孔材料孔结构、改性方法、改性剂相对用量对CO2吸附性能有较大的影响；通过物理浸渍法,采用聚乙烯亚胺(PEI)对阶层多孔二氧化硅(H-SiO2)进行氨基改性,所得材料吸附量可达1.37mmol/g;通过化学接枝法,采用3-氨丙基三乙氧基硅烷(APTES)对大孔(T-SiO2)及阶层多孔二氧化硅(H-SiO2)进行氨基改性,所得材料吸附量达1.45mmol/g、 1.30mmol/g。氨基改性阶层多孔Si02材料具有较强的CO2吸附性能,在长效吸附CO2领域具有应用前景。
[Abstract]:Hierarchical porous silicon dioxide (Si02) block is a kind of porous material with macroporous, mesoporous or microporous gradient distribution. It has the characteristics of three-dimensional coherent macroporous structure, fine mesoporous structure and so on, so it has the characteristics of high specific surface area, high adsorption, high porosity and so on. In the separation, adsorption, filtration, catalysis and other important fields have a broad application prospects. Sol-gel accompanied phase separation method is an effective way to prepare layered porous Si02 bulk materials. However, the preparation process needs high temperature post-treatment, and the mesoporous structure is disordered, and the modification process is complex and toxic modified solvent is used. Reductant, etc. On the basis of synthetically discussing the preparation of layered porous bulk materials by sol-gel accompanying phase separation, the preparation of macroporous SiO2 block and layered porous Si02 block, the environmentally friendly surface modification of porous block and its silver loading, CO2 trapping and so on have been studied in this paper. The mechanisms of co-continuous macroporous structure controlled by sol-gel transformation and phase separation, ordered mesoporous structure of rod-like micelle template, modified porous framework of amino surface and reduction of silver ions by ethylene glycol were analyzed. It lays a foundation for the application of layered porous Si02 bulk materials in high performance liquid chromatography (HPLC) separation, catalytic reaction and CO2 trapping. The main contents and results are as follows: (1) with methyl orthosilicate (TMOS) as precursor, 0.01 mol L-1 (HCL) as catalyst, poly (ethylene oxide) (PEO) as phase separation agent, epoxypropane (PO) as gel promoter. The porous Si02 bulk with three dimensional coherent macropores and specific surface area of 418m2.g-1 was prepared by sol-gel accompanying phase separation method. On this basis, the porous Si02 bulk material was prepared by introducing the pore-making agent SDS. The mesoporous pore size is 4-5 渭 m and the mesoporous pore size is 4-5 渭 m. (2) using TMOS as precursor, 0.01 mol L-1 hydrochloric acid as catalyst, and propylene oxide (PO) as gel accelerator, mesoporous pore size is 4-5 渭 m, and mesoporous pore size is 4-5 渭 m. Using triblock copolymers (Pluronic P123) and trimethylbenzene (TMB) as template and expander, the layered porous Si02 blocks with continuous macroporous skeleton and ordered mesoporous structure were prepared by one step method. The macroporous pore size is 1-2 渭 m, and the mesoporous pore size is 10-11 nm, the specific surface area of which is as high as 848m2 g-1 / 8000C. (3) the porous Si02 is relatively nontoxic modified and silver loaded with 3- aminopropyl triethoxysilane (APTES) as modifier. Ethanol was used as the modified solvent for the first time, and ethylene glycol was used as reducing agent for the first time. The silver nanoparticles were loaded on the modified Si02 by its reductivity, and the silver loading rate could reach 15.44 wt. The modification and reduction mechanism, the influence factors of silver loading amount, and the improvement of specific surface area of silver loaded porous Si02 block by appropriate temperature heat treatment were discussed. (4) Amino modification was carried out on the prepared layered porous Si02. The CO2 adsorption properties of amino modified macroporous and layered porous Si02 bulk materials were investigated. The results show that the pore structure, modification method and the relative amount of modifier have great influence on the adsorption properties of CO2, and polyvinyleneimide (PEI) is used to modify the porous silica (H-SiO2) by physical impregnation. The adsorption capacity of the obtained material can reach 1.37 mmol / g, and the amino modification of macroporous (T-SiO2) and layered porous silica (H-SiO2) by 3-aminopropyl triethoxy silane (APTES) is reported. The adsorption capacity of the obtained material is 1.45 mmol / g and 1.30 mmol / g respectively. Amino-modified porous Si02 materials have strong CO2 adsorption properties and have a promising application in long-term adsorption of CO2.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O613.72;TB383.4
本文编号：2286874
[Abstract]:Hierarchical porous silicon dioxide (Si02) block is a kind of porous material with macroporous, mesoporous or microporous gradient distribution. It has the characteristics of three-dimensional coherent macroporous structure, fine mesoporous structure and so on, so it has the characteristics of high specific surface area, high adsorption, high porosity and so on. In the separation, adsorption, filtration, catalysis and other important fields have a broad application prospects. Sol-gel accompanied phase separation method is an effective way to prepare layered porous Si02 bulk materials. However, the preparation process needs high temperature post-treatment, and the mesoporous structure is disordered, and the modification process is complex and toxic modified solvent is used. Reductant, etc. On the basis of synthetically discussing the preparation of layered porous bulk materials by sol-gel accompanying phase separation, the preparation of macroporous SiO2 block and layered porous Si02 block, the environmentally friendly surface modification of porous block and its silver loading, CO2 trapping and so on have been studied in this paper. The mechanisms of co-continuous macroporous structure controlled by sol-gel transformation and phase separation, ordered mesoporous structure of rod-like micelle template, modified porous framework of amino surface and reduction of silver ions by ethylene glycol were analyzed. It lays a foundation for the application of layered porous Si02 bulk materials in high performance liquid chromatography (HPLC) separation, catalytic reaction and CO2 trapping. The main contents and results are as follows: (1) with methyl orthosilicate (TMOS) as precursor, 0.01 mol L-1 (HCL) as catalyst, poly (ethylene oxide) (PEO) as phase separation agent, epoxypropane (PO) as gel promoter. The porous Si02 bulk with three dimensional coherent macropores and specific surface area of 418m2.g-1 was prepared by sol-gel accompanying phase separation method. On this basis, the porous Si02 bulk material was prepared by introducing the pore-making agent SDS. The mesoporous pore size is 4-5 渭 m and the mesoporous pore size is 4-5 渭 m. (2) using TMOS as precursor, 0.01 mol L-1 hydrochloric acid as catalyst, and propylene oxide (PO) as gel accelerator, mesoporous pore size is 4-5 渭 m, and mesoporous pore size is 4-5 渭 m. Using triblock copolymers (Pluronic P123) and trimethylbenzene (TMB) as template and expander, the layered porous Si02 blocks with continuous macroporous skeleton and ordered mesoporous structure were prepared by one step method. The macroporous pore size is 1-2 渭 m, and the mesoporous pore size is 10-11 nm, the specific surface area of which is as high as 848m2 g-1 / 8000C. (3) the porous Si02 is relatively nontoxic modified and silver loaded with 3- aminopropyl triethoxysilane (APTES) as modifier. Ethanol was used as the modified solvent for the first time, and ethylene glycol was used as reducing agent for the first time. The silver nanoparticles were loaded on the modified Si02 by its reductivity, and the silver loading rate could reach 15.44 wt. The modification and reduction mechanism, the influence factors of silver loading amount, and the improvement of specific surface area of silver loaded porous Si02 block by appropriate temperature heat treatment were discussed. (4) Amino modification was carried out on the prepared layered porous Si02. The CO2 adsorption properties of amino modified macroporous and layered porous Si02 bulk materials were investigated. The results show that the pore structure, modification method and the relative amount of modifier have great influence on the adsorption properties of CO2, and polyvinyleneimide (PEI) is used to modify the porous silica (H-SiO2) by physical impregnation. The adsorption capacity of the obtained material can reach 1.37 mmol / g, and the amino modification of macroporous (T-SiO2) and layered porous silica (H-SiO2) by 3-aminopropyl triethoxy silane (APTES) is reported. The adsorption capacity of the obtained material is 1.45 mmol / g and 1.30 mmol / g respectively. Amino-modified porous Si02 materials have strong CO2 adsorption properties and have a promising application in long-term adsorption of CO2.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O613.72;TB383.4
【参考文献】
相关期刊论文 前1条
1 ;Molecularly imprinted macroporous monolithic materials for protein recognition[J];Chinese Chemical Letters;2011年11期
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