物理化学学报 >> 1998, Vol. 14 >> Issue (02): 142-146.doi: 10.3866/PKU.WHXB19980209

研究论文 上一篇    下一篇

不同干燥过程对超细TiO2粉体性质的影响

董国利, 高荫本, 陈诵英   

  1. 中国科学院山西煤炭化学研究所 煤转化国家重点实验室,太原 030001
  • 收稿日期:1997-05-23 修回日期:1997-09-15 发布日期:1998-02-15
  • 通讯作者: 董国利

Effect of Different Drying Methods on the Properties of TiO2 Particles

Dong Guo-Li, Gao Yin-Ben, Chen Song-Ying   

  1. State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001
  • Received:1997-05-23 Revised:1997-09-15 Published:1998-02-15
  • Contact: Dong Guo-Li

摘要:

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.

关键词: 超临界流体干燥法, 常规干燥法, TiO2

Abstract:

The effects of different drying methods on the properties of TiO2 powders have been studied. Usually in the case of conventional drying, various forces mainly in the form of capillary press cause differential macroscopic and microscopic shrinkage and the gel structure cracks, so the specific surface areas and pore volumes are small for hydrogel or alcolgel prepared. The supercritical fluid drying (SCFD) can eliminate any liquid-vapor interface inside the gel during solvent extraction. so avoiding the macroscipic or microscopic collapse and preserving the structure of the wet gel. so the specific surface areas and pore volumes of aerogel botaied has the largest values.
These ultrafine powders prepared by the supercritical drying have reproductive high surface areas and large pore volumes.

Key words: Supercritical fluid drying, Convertional drying, TiO2, Ultrafine particle