Micro- and nanospheres from preceramic polymers: process parameters and size control
Micro- and nanospheres from preceramic polymers: process parameters and size control
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DOI：
10.1007/s10853-012-6359-5
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发表时间：
2012-03
影响因子：
4.5
通讯作者：
Verena Reschke;M. Scheffler
中科院分区：
文献类型：
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作者：
Verena Reschke;M. Scheffler
采用一种简单的固化工艺，在油水乳化过程中，用液体陶瓷前驱体聚合物制备了聚合物和多孔陶瓷微球和纳米球。该体系由水可交联的聚（甲氧基甲基硅氧烷）作为预陶瓷聚合物和线性羟基封端的聚（二甲基硅氧烷）作为原位水生成源组成。在表面活性剂和交联活性有机金属催化剂的存在下，通过超声处理进行乳化，随后进行固化。研究了聚合物基体系的流变行为，考察了交联行为与催化剂浓度和温度的关系。组合物和工艺参数，如能量输入和类型和浓度的表面活性剂的影响，确定相对于所获得的聚合物球的微观结构和粒度分布。所合成的球的粒径主要在亚微米范围内。在1073.15 K的氩气气氛中进行热解，导致在形状保持下形成非晶陶瓷。
Polymeric and porous ceramic micro- and nanospheres were prepared by a simple solidification process with a liquid preceramic polymer in an oil–water-emulsification process. The system was composed of a water-crosslinkable poly(methoxymethylsiloxane) as the preceramic polymer and a linear hydroxyl-terminated poly(dimethylsiloxane) as a source for in situ water generation. Emulsification followed by subsequent curing was carried out via an ultrasonic treatment in the presence of surfactants and a crosslinking active organometallic catalyst. The rheological behavior of the polymeric base system was characterized and the crosslinking behavior was investigated as a function of catalyst concentration and temperature. Effects of composition and processing parameters such as energy input and type and concentration of the surfactant were determined with respect to the microstructure and particle size distribution of the obtained polymeric spheres. The particle diameters of the as-synthesized spheres were mainly in the sub-micron range. Pyrolysis was performed in argon atmosphere at 1073.15 K resulting in the formation of amorphous ceramics under shape retention.