Sol-Gel Processing of Silicates
Sol-Gel Processing of Silicates
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硅酸盐的溶胶-凝胶加工
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
L. Klein
中科院分区：
文献类型：
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作者：
L. Klein
Sol-Gel工艺是指涉及溶液或经历Sol-Gel转变的溶胶的众多工艺中的任何一种。在转变过程中，溶液或溶胶通过失稳、沉淀或过饱和(1-4)变成坚硬的、多孔的物质。不是通过尝试精确的定义来限制工艺的这种分类，而是通过使用一个例子来开发对溶胶-凝胶工艺的一种特殊的定义。符合一种定义的一个例子是正硅酸乙酯(TEOS)、水和乙醇体系。这是一种真正的单相溶液，通过溶胶-凝胶转变为固体二氧化硅和充满溶剂的孔隙的刚性两相体系。这种情况下的溶胶-凝胶转变是不可逆的。将一个相转变为两个相的机制还不完全清楚，尽管转变手段的后果在凝胶中是相当明显的(5-8)。为了阐明Sol-Gel转变的机理，对Sol-Gel过程的几个较好的理解方面进行了综述。这些方面是水解反应、缩合聚合、干燥和致密化。
The sol-gel process is the name applied to any one of a number of processes that involve a solution or sol that undergoes a sol-gel transition. At the transition, the solution or sol becomes a rigid, porous mass through destabilization, precipitation, or supersaturation (1-4). Rather than restrict this classification of processes by attempting an exact definition, one par ticular definition of a sol-gel process will be developed here by use of an example. An example that fits one definition is the system tetraethylortho silicate (TEOS), water, and ethanol. This is a true one-phase solution that goes through a sol-gel transition to a rigid two-phase system of solid silica and solvent-filled pores. The sol-gel transition in this case is not reversible. The mechanism that transforms one phase into two phases is not entirely understood, though the consequences of the means of transition are quite evident in the gels (5-8). In order to formulate a mechanism for the sol-gel transition, several of the better-understood aspects of the sol-gel process are reviewed. These aspects are hydrolysis reactions, condensation polymer ization, drying, and densification.