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无机材料学报

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SnO2凝胶干燥及固化过程中的结构变化

郭玉忠1; 王剑华1; 孙加林2   

  1. 1. 昆明理工大学新材料制备与加工省重点实验室, 昆明 650093; 2. 昆明贵金属研究所, 昆明 650221
  • 收稿日期:2000-08-22 修回日期:2000-11-01 出版日期:2001-05-20 网络出版日期:2001-05-20

Structural Evolution During Drying and Solidification of SnO2 Gels

GUO Yu-Zhong1; WANG Jian-Hua1; SUN Jia-Lin 2   

  1. 1. Novel Materials Preparation & Processing Provincial Laboratory; Kunming University Of Science & Technology; Kunming 650093; China; 2. Institute of Precious Metals; Kunming 650221; China
  • Received:2000-08-22 Revised:2000-11-01 Published:2001-05-20 Online:2001-05-20

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摘要： 通过ＴＧ－ＤＴＡ、ＢＥＴ－Ｎ２吸附和Ｘ衍射分析，详细研究了ＳｎＯ２凝胶在２０～７００℃区间干燥固化过程中的收缩、失重机理、凝胶骨架纳米结构的变化规律，研究了掺杂元素Ｓｂ、溶胶阶段加入的催化剂和溶剂种类对干燥过程和固化过程中结构演变的影响．研究发现：ＳｎＯ２凝胶为１～１０ｎｍ尺寸的纳米多孔结构，符合圆柱通孔模型．在干燥固化过程分别为２０～２００℃、２００～５５０℃和＞５５０℃三个不同阶段，分别发生骨架吸附溶剂解附、－ａｃａｃ 螯环分解氧化、网链结构驰豫和无定型→晶态转变等四个过程，它们是支配凝胶失重、收缩、固化的主要机理．随团化温度增加；纳米骨架粗化长大但其径长比保持不变，同时Ｓｂ加入有细化骨架作用，而催化剂对凝胶结构无明显影响．

关键词: SnO2凝胶, 干燥-固化过程, 骨架结构, 圆柱通孔模型

Abstract: This paper dealt with in detail the drying-solidification process, contraction and weight-loss
mechanisms, skeleton nanostructures and its evolution trends with temperature increasing for SnO2 gel system within 20～700℃
heat-treatment interval by TG-DTA, BET-N2 adsorption, and X-ray diffraction three measuring methods, and further covered with the influences of doping Sb
addition amounts, catalysts and solvents needed in sol stage on drying process and nanostructure of SnO2 gels. Based on the measurements and
analysis, it is shown that SnO2 gels are of porous nanostructure of size 1～15nm, in good agreement with Sherer’s Cylinder Skeleton Model, and drying solidification
includes three evolution stages: 20～200℃, 200～550℃ and >550℃, in which the desorption of solvents on the surfaces of gel skeleton,
break-up and oxidation of --acac ring chelated on Sn atom, structural relaxion of gel chain net and gel skeleton crystallization are responsible for the
weight-loss, contraction and solidification of gels, as temperature increases, the nano-skeleton coarsens and enlarges but keeps its radium-length ratio unchanged,

Key words: SnO2 gels, drying-solidification process, nanostructure, cylinder model

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