| 三氟丙基修饰的二氧化硅膜制备、氢气分离及其水热稳定性能 | |
| Preparation, H2 Separation and Hydrothermal Stability of Trifluoropropyl-Modified Silica Membranes | |
| 摘要: 以三氟丙基三甲氧基硅烷(TFPTMS)和正硅酸乙酯(TEOS)作为前驱体,通过溶胶-凝胶法制备三氟丙基修饰的SiO2膜材料,研究了三氟丙基修饰对膜材料孔结构和疏水性的作用、疏水膜材料的氢气渗透和分离性能以及水热稳定性能。结果表明三氟丙基修饰后的膜材料仍保持良好的微孔结构,孔径狭窄分布在0.45～0.7 nm之间。修饰后膜材料疏水性明显提高,当nTFPTMS/nTEOS=0.6时,对水的接触角达到(102.7°±0.1°)。H2在修饰后膜材料的输运遵循微孔扩散机理,在300 ℃时,H2的单组份渗透率达到4.77×10-7 mol·m-2·s-1·Pa-1,H2/CO2的理想分离系数以及双组份分离系数分别达到6.99和6.93,均高于其Knudsen扩散分离因子。在200 ℃水蒸气物质的量含量为5%的环境中陈化220 h后,H2的单组份渗透率仅在前3 h有轻微下降,然后基本保持不变,说明三氟丙基修饰的SiO2膜具有良好的水热稳定性。 | |
| 关键词: 二氧化硅膜 溶胶-凝胶法 疏水性 气体分离 水热稳定性 | |
| 基金项目: 国家自然科学基金(No.21171014,50502002);国家863计划课题(No.2009AA03Z213);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)资助项目。 | |
| Abstract: Trifluoropropyl-modified silica membranes were prepared by sol-gel technique using tetraethyl orthosilicate (TEOS) and (trifluoropropyl)trimethoxysilane (TFPTMS) as precursors. The effect of trifluoropropyl modification on the hydrophobic pore structure, properties, hydrogen permeation and separation properties and long-term hydrothermal stability of the modified silica membranes were investigated in detail. The results show that the modified membranes retain a desirable microporous structure with a pore size distributed from 0.45 to 0.7 nm. The hydrophobic property of silica membranes has been considerably enhanced after modification, with a water contact angle of (102.7°±0.1°) at a TFPTMS/TEOS molar ratio of 0.6. The hydrogen transport in the modified silica membranes complies with a micropore diffusion mechanism, with a single H2 permeance of 4.77×10-7 mol·m-2·s-1·Pa-1, a H2/CO2 permselectivity of 6.99 and a H2/CO2 binary gas mixture separation factor of 6.93 at 300 ℃, higher than Knudsen permselectivity (4.69). Under a humid condition with a temperature of 200 ℃ and a water vapor molar ratio of 5%, the single H2 permeance slightly decrease in the first 3 hours and then almost remain constant for at least 220 hours, indicating that the modified membranes are more hydrothermally stable than pure SiO2 membranes. | |
| Keywords: silica membrane sol-gel technique hydrophobic property gas separation hydrothermal stability | |
| 投稿时间：2012-10-10 修订日期：2013-01-28 | |
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| 洪志发,韦奇,李国华,王学伟,聂祚仁,李群艳.三氟丙基修饰的二氧化硅膜制备、氢气分离及其水热稳定性能[J].无机化学学报,2013,29(5):941-947. | |
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