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摘要本文以正硅酸乙酯（TEOS）为硅源，氨水溶液为催化剂，聚乙烯吡咯烷酮（PVP）功能化的聚苯乙烯为模版，在乙醇介质中利用一步法制得纳米空心二氧化硅，并用TEM，XRD，BET，TG，FTIR 等表征手段对 SiO2粉体进行分析。 首先,以苯乙烯（St）为单体，过硫酸铵为引发剂，聚乙烯吡咯烷酮为分散剂，水为分散介质，单分散聚合法制备功能化的聚苯乙烯，可得到平均粒径为 90nm的聚苯乙烯微球。以这种微球为模版，在乙醇/氨水介质中，正硅酸乙酯发生水解和缩合，在聚苯乙烯微球包覆形成 SiO2，同时 PS 核被溶解，得到纳米空心二氧化硅微球。研究氨水用量，TEOS 用量及反应时间等因素对二氧化硅微球形貌和产率的影响。 以空心纳米二氧化硅为 Li3PO4 催化剂载体，催化环氧丙烷的异构化，与以硅胶作为载体的 Li3PO4催化剂的催化效果进行比较。结果表明，使用空心球形二氧化硅代替硅胶作为催化剂载体可提高环氧丙烷转化率和烯丙醇的选择性，降低反应温度和副产物选择性。6619
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关键词 ：中空纳米二氧化硅 模板法 环氧丙烷 烯丙醇
毕业设计说明书（论文）外文摘要
Title Systhesis of Nano hollow silica and the application in the
preparation of the eggshell-shaped catalyst
Abstract
This article prepares hollow SiO2 nanoparticles with the template one step method,
using tetraethyl orthosilicate (TEOS) as the silica source, ammonia water as the
catalyst, polyvinylpyrrolidone (PVP) functionalized polystyrene as the templates .The
basic performances of SiO2 powder were characterized by means of TEM,XRD,BET
and FTIR .
First, using styrene as the monomer, ammonium persulfate as the initiator,
polyvinylpyrrolidone( PVP) as the stabilizer, PVP functionalized polystyrene
microspheres(PVP/PS) was prepared, whose average size is 90nm. In ethanol/ammonia
water medium , hydrolyzation and condensation of TEOS were completed, SiO2 shells
were built around the PVP/PS templates, meanwhile PS nuclears were dissolved ,
hollow silica microspheres were obtained. The main factor influencing for the
morphology and productivity of SiO2 as the amount of ammonia water, TEOS and
reaction time etc were investigated.
Using Nano hollow silica as Li3PO4 catalyst carrier, Li3PO4/SiO2 as the catalyst in
the isomerization of propylene oxide, catalytic properties were measured and was
compared with catalyst using silica gel as the carrier. The results show that using Nano
hollow silica instead of silica gel as the catalyst carrier, the conversion rate of
propylene oxide and the selectivity of allyl alcohol were improved, and the selectivity
of by-products and the reaction temperature was reduced
Keywords: Nano hollow silica Template method Propylene oxide Allyl alcohol
目次
第一章 绪论 1
1.1 纳米科学与纳米材料 . 1
1.2 纳米材料的特性 . 1
1.2.1 小尺寸效应 1
1.2.2 表面效应 . 2
1.2.3 宏观量子隧道效应 . 2
1.2.4 量子尺寸效应 . 2
1.3 空心球结构纳米材料的研究和发展现状 2
1.4 空心球结构纳米材料的制备 3
1.4.1 模板法 . 3
1.4.2 喷雾干燥法 . 3
1.4.3 层层自组装法 . 4
1.4.4 超声波法 . 4
1.4.5 模板-界面反应法 5
1.4.6 微乳液法 . 5
1.5 空心纳米二氧化硅微球的制备方法及研究现状 5
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