论文部分内容阅读
考察了采用不同干燥工艺制备的TiO2粉体在粒子形貌、颗粒大小与分布、晶相组成以及比表面积和孔结构等织构和结构性质方面的差异。结果表明，利用常规的干燥方法，由水凝胶脱水所得的颗粒，颗粒间严重团聚，颗粒粒径大且分布不均匀，比表面积和孔体积最小；由醇凝胶直接脱水，则可以显著提高粉体的织构性能．而采用超临界流体干燥法则可以进一步提高粉体的性能，比表面积由水凝胶的4．88m2·g－1增大到113．8m2·g－1，提高了近30倍；孔体积由0．027cm3·g－1增大到0．41cm3·g-1．大约提高了15倍；而且其能够有效地防止粒子间的团聚，较好地保持了湿凝胶的网络结构，使颗粒尺寸降低且分布均匀，可重复性好．
The differences of texture and structure properties of TiO2 powders prepared by different drying processes were investigated in terms of particle morphology, particle size and distribution, crystal phase composition, specific surface area and pore structure. The results showed that the particles obtained by the dehydration of hydrogels had serious agglomeration, large particle size and uneven distribution, and the smallest specific surface area and pore volume by the conventional drying method. Direct dehydration of the alcohol gel could significantly increase Texture properties of powder. The supercritical fluid drying method can further improve the performance of the powder, the specific surface area increased from 4.88m2 · g-1 hydrogel to 113.8m2 · g-1, an increase of nearly 30 times; pore volume from 0 .027cm3 · g-1 increased to 0.41cm3 · g-1. About 15-fold increase; and it can effectively prevent agglomeration between particles, better maintain the network structure of the wet gel, so that the particle size is reduced and uniform distribution, good repeatability.