Effect of polyvinylpyrrolidone on the ammonia-catalyzed sol-gel process of TEOS: Study by in situ Si-29 NMR, scattering, and rheology
文献类型：期刊论文
| 作者 | Xu, Yao; Wu, Dong; Sun, Yuhan; Chen, Wenxue; Yuan, Hanzhen; Deng, Feng; Wu, Zhonghua |
| 刊名 | COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
 |
| 出版日期 | 2007-09-15 |
| 卷号 | 305期号:1-3页码:97-104 |
| 关键词 | reaction kinetics siloxane Si-29 NMR SAXS rheology |
| 英文摘要 | Ammonia-catalyzed sol-gel process of polyvinylpyrrolidone/tetraethoxysilane (PVP/TEOS) system in methanol was studied by in situ liquid Si-29 nuclear magnetic resonance (NMR), dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and rheology. A scientific connection was established between the reaction composition and the microstructures of sol particles. It was found that the concentration of PVP played an important role in the hydrolysis kinetics of TEOS and the SiO2 sol-gel process. The results of in Situ Si-29 NMR showed that PVP addition reduced both hydrolysis rate and condensation rate of TEOS, and the condensation rate decreased more seriously than the hydrolysis rate. The particle size distributions obtained from DLS and SAXS indicated that PVP held back the growth Of SiO2 clusters by hydrogen-bonding the silanol groups on particle surface with the electronegative inner amide of PVP side chain. Thus, gelation was retarded and the rheology of sol was largely modified by PVP. Rheology study showed typical Newtonian fluid behavior before gelation and shear thinning fluid behavior after gelation point, respectively. The changes in fractal dimensions of PVP/SiO2 sols, obtained by SAXS, explained the different microstructures of SiO2 sol particles in the presence of PVP. The changes of microstructure and macroscopic properties should be pre-determined by the very early stages of sol-gel process. (c) 2007 Elsevier B.V. All rights reserved. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 类目[WOS] | Chemistry, Physical |
| 研究领域[WOS] | Chemistry |
| 关键词[WOS] | X-RAY-SCATTERING ; MODIFIED SILICA-GELS ; 2 FRACTAL STRUCTURES ; HYBRID MATERIALS ; STOBER SYNTHESIS ; STATE NMR ; SAXS ; KINETICS ; PYRROLIDONE) ; COMPOSITES |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000249254900015 |
| 公开日期 | 2015-10-13 |
| 源URL | [http://ir.wipm.ac.cn/handle/112942/7924]  |
| 专题 | 武汉物理与数学研究所_2011年以前论文发表（包括2011年） |
| 作者单位 | 1.Chinese Acad Sci, Inst Coal Chem, State Kay Lab Coal Convers, Taiyuan 030001, Peoples R China 2.Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China 3.Chinese Acad Sci, Inst High Energy Phys, Lab Synchrotron Radiat, Beijing 100039, Peoples R China |
| 推荐引用方式 GB/T 7714 | Xu, Yao,Wu, Dong,Sun, Yuhan,et al. Effect of polyvinylpyrrolidone on the ammonia-catalyzed sol-gel process of TEOS: Study by in situ Si-29 NMR, scattering, and rheology[J]. COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS,2007,305(1-3):97-104. |
| APA | Xu, Yao.,Wu, Dong.,Sun, Yuhan.,Chen, Wenxue.,Yuan, Hanzhen.,...&Wu, Zhonghua.(2007).Effect of polyvinylpyrrolidone on the ammonia-catalyzed sol-gel process of TEOS: Study by in situ Si-29 NMR, scattering, and rheology.COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS,305(1-3),97-104. |
| MLA | Xu, Yao,et al."Effect of polyvinylpyrrolidone on the ammonia-catalyzed sol-gel process of TEOS: Study by in situ Si-29 NMR, scattering, and rheology".COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 305.1-3(2007):97-104. |
入库方式： OAI收割
来源：武汉物理与数学研究所
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