階層多孔二氧化硅塊體材料的制備及其應(yīng)用研究
發(fā)布時間：2018-10-22 10:10
【摘要】：階層多孔二氧化硅(Si02)塊體是一種大孔、介孔或微孔梯度分布的多孔材料,具有三維連貫大孔、精細介孔結(jié)構(gòu)等孔道特征,因而擁有高比表面積、高吸附、高氣孔率等特性,在分離、吸附、過濾、催化等重要領(lǐng)域具有廣闊的應(yīng)用前景。溶膠-凝膠伴隨相分離法是制備階層多孔Si02塊體材料的有效途徑,但目前制備流程需要高溫后處理,且介孔結(jié)構(gòu)無序,在修飾改性方面也存在工序復(fù)雜及使用有毒改性溶劑、還原劑等問題。本論文在綜合論述了溶膠-凝膠伴隨相分離制備階層多孔塊體材料的基礎(chǔ)上,研究了大孔SiO2塊體及階層多孔Si02塊體制備、多孔塊體的環(huán)保表面改性及其銀負載、CO2捕捉等內(nèi)容,分析了溶膠-凝膠轉(zhuǎn)化與相分離協(xié)同控制形成共連續(xù)大孔結(jié)構(gòu)、棒狀膠束模板形成有序介孔結(jié)構(gòu)、氨基表面改性多孔骨架、乙二醇還原銀離子等機理,為階層多孔Si02塊體材料在高效液相色譜分離、催化反應(yīng)、CO2捕捉等領(lǐng)域應(yīng)用奠定基礎(chǔ)。主要研究內(nèi)容及結(jié)果如下：(1)以正硅酸甲酯(TMOS)為前驅(qū)體、0.01 mol·L-1鹽酸(HCL)為催化劑、聚環(huán)氧乙烷(PEO)為相分離劑、環(huán)氧丙烷(PO)為凝膠促進劑,采用溶膠-凝膠伴隨相分離法制備具有三維連貫大孔,且比表面積418m2.g-1多孔Si02塊體；在此基礎(chǔ)上,引入造孔劑SDS制備階層多孔Si02塊體材料,大孔孔徑為1-3μm,介孔孔徑為4-5 nm,比表面積可達650m2·g-1。(2)以TMOS為前驅(qū)體、0.01 mol·L-1鹽酸為催化劑、環(huán)氧丙烷(PO)為凝膠促進劑,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)為模板劑及膨脹劑,一步法直接制備兼具連續(xù)大孔骨架及有序介孔結(jié)構(gòu)的階層多孔Si02塊體,大孔孔徑為1-2μm,介孔孔徑為10-11 nm,比表面積高達848m2·g-1,8000C熱處理后仍能保持該階層多孔結(jié)構(gòu)穩(wěn)定。(3)對制備的階層多孔Si02進行相對無毒改性及銀負載。3-氨丙基三乙氧基硅烷(APTES)作為改性劑,首次采用乙醇為改性溶劑,對其進行改性；首次采用乙二醇為還原劑,利用其還原性對改性后Si02進行銀納米顆粒負載,銀負載率可達15.44wt.%。探究其改性及還原機理、銀負載量影響因素,并提出通過適當溫度熱處理方法來提高銀負載階層多孔Si02塊體的比表面積。(4)對制備的階層多孔Si02進行氨基改性,考察氨基改性大孔及階層多孔Si02塊體材料的CO2吸附性能。測試表明：多孔材料孔結(jié)構(gòu)、改性方法、改性劑相對用量對CO2吸附性能有較大的影響；通過物理浸漬法,采用聚乙烯亞胺(PEI)對階層多孔二氧化硅(H-SiO2)進行氨基改性,所得材料吸附量可達1.37mmol/g;通過化學(xué)接枝法,采用3-氨丙基三乙氧基硅烷(APTES)對大孔(T-SiO2)及階層多孔二氧化硅(H-SiO2)進行氨基改性,所得材料吸附量達1.45mmol/g、 1.30mmol/g。氨基改性階層多孔Si02材料具有較強的CO2吸附性能,在長效吸附CO2領(lǐng)域具有應(yīng)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.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：O613.72;TB383.4
本文編號：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.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：O613.72;TB383.4
【參考文獻】
相關(guān)期刊論文 前1條
1 ;Molecularly imprinted macroporous monolithic materials for protein recognition[J];Chinese Chemical Letters;2011年11期
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