Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (24): 2529-2535.DOI: 10.6023/A12080568 Previous Articles     Next Articles



王学伟, 韦奇, 洪志发, 李群艳, 聂祚仁   

  1. 北京工业大学材料科学与工程学院 北京 100124
  • 投稿日期:2012-08-20 发布日期:2012-11-26
  • 通讯作者: 韦奇
  • 基金资助:

    项目受国家自然科学基金(Nos. 21171014, 50502002)、国家863计划(No. 2009AA03Z213)和浙江省绿色化学合成技术国家重点实验室培育基地开放基金(No. GCTKF2012016)资助.

Preparation, Gas Separation and Hydrothermal Stability Property of Organic-inorganic Hybrid Silica Membranes Modified by Trifluoropropyl Groups

Wang Xuewei, Wei Qi, Hong Zhifa, Li Qunyan, Nie Zuoren   

  1. College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124
  • Received:2012-08-20 Published:2012-11-26
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21171014 and 50502002), the National High Technology Research and Development Program of China (863 Program) (No. 2009AA03Z213) and the Open Foundation of State Key Laboratory Breeding Base of Green Chemistry- Synthesis Technology of Zhejiang Province (No. GCTKF2012016).

Organic-inorganic hybrid silica membranes modified with trifluoropropyl groups were synthesized by acid-catalyzed co-hydrolysis and polycondensation reaction of (3,3,3-trifluoropropyl)trimethoxysilane (TFPTMS) and bridged silsesquioxane 1,2-bis(triethoxysilyl)ethane (BTESE) as co-precursors. The effect of trifluoropropyl groups on the sol particle size and the hydrophobic property, the hydrogen permeation and separation behavior and the hydrothermal stability of the obtained membranes were investigated in detail. The results show that trifluoropropyl groups have been successfully incorporated onto the surface of membranes. The sol particle size decreases gradually and hydrophobic properties of the modified silica membranes are enhanced with increasing amount of TFPTMS in the mixture. When the molar ratio of TFPTMS/BTESE increases to 0.6, the organic-inorganic hybrid silica membranes exhibit water contact angles of 111.6°±0.7° and a narrow sol particle size distribution centered at 2.11 nm. The transport of hydrogen in the modified hybrid silica membranes complies with a micropore diffusion mechanism, with a high hydrogen permeance of 8.86×10-7 mol·m-2·s-1·Pa-1, a H2/CO2 permselectivity of 5.4, and a H2/CO2 binary gas (molar ratio=1∶1) separation factor of 4.82 at 300 ℃, higher than the corresponding Knudsen value (H2/CO2=4.69). The modified organic-inorganic silica membranes are hydrothermally stable while aging at a humid atmosphere with a temperature of 250 ℃ and a steam concentration of 5% for more than 300 hours.

Key words: trifluoropropyl groups, organic-inorganic hybrid silica membranes, hydrogen separation, hydrothermal stability