色谱

色谱

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碱溶法制备高孔隙度多孔微球

赵睿,李新会,刘国诠

  

  1. Center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100080, China
  • 收稿日期:2004-10-22 修回日期:1900-01-01 出版日期:2005-11-30 发布日期:1987-12-25
  • 通讯作者: 赵睿

Preparation of Porous Silica Microspheres with High Porosity Using Base-Dissolving Method

ZHAO Rui, LI Xinhui, LIU Guoquan   

  1. Center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100080, China
  • Received:2004-10-22 Revised:1900-01-01 Online:2005-11-30 Published:1987-12-25

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摘要：

提出并研究了以碱溶侵蚀提高多孔硅球孔隙度的新方法,研究了碱液浓度、处理温度、反应时间与洗除量的关系。结果表明,随着NaOH浓度的提高,不仅洗除量加大,而且硅胶的溶解速度亦少许增大,其主要原因是由于某些孔结构的塌陷导致了细屑的脱除。温度升高和处理时间延长会导致洗除量增大。随着洗除量的增加,硅胶的比孔容呈线性增大,但其外观仍为均匀的球形,且直径亦未见明显变化。选用粒径4~5 μm、孔径8 nm、比孔容1.4 cm3/g的多孔硅胶,采用1.25 mol/L NaOH水溶液、室温(25 ℃)处理3.0 h,制备了粒径4~5 μm、孔径14 nm、比孔容3.2 cm3/g的高孔隙度多孔硅胶,其孔隙度从75%增加到88%。

关键词: 多孔硅胶, 高孔隙度
, 碱溶法

Abstract:

A novel method was proposed and studied for the preparation of porous silica with high porosity using base-dissolving technology. The relationships between the removal of silica and the base concentration, the reaction temperature as well as the reaction time were evaluated. The amount of silica removed from silica spheres was increased and silica-dissolving rate was also accelerated along with the increase of NaOH concentration. This was due to the damage of some inner walls of the porous silica and the dissolution of small fragments into the base solution. The amount of silica removed was in direct proportion to the reaction temperature and reaction time. Moreover, the specific pore volumes were linearly increased along with the increase of the amount of silica removed. The treated silica particles remained as homogeneous spheres and the changes of the particle diameter were not observed. Under the optimized conditions with the NaOH solution of 1.25 mol/L, the reaction temperature of 25 ℃ and the reaction time of 3.0 h, the original silica spheres with the diameter of 4-5 μm, the pore size of 8 nm and the specific pore volume (Vp) of 1.4 cm3/g were modified to the high-porosity silica with the diameter of 4-5 μm, the pore size of 14 nm and the Vp of 3.2 cm3/g. The porosity of the silica microspheres was changed from 75% to 88%. This high-porosity silica was suitable for the preparation of high performance gel filtration packings.

Key words: high porosity , porous silica, base-dissolving method