摘要
制奋了聚二甲基硅氧烷和多孔聚丙的复合膜,并分别用以分离O_2、N_2和以渗透汽化法分离乙醇—水混合物。结果表明,当复合膜较薄时,膜的选择性对气体保持不变,而对渗透汽化法却大幅度下降。说明尽管气体膜分离与液体混合物的渗透汽化分离都遵循“溶解扩散”机理,但是溶解和扩散对选择性的贡献在两种情况下,程度是不同的。计算了氧、氮、乙醇和水的透过活化能,分别为6.7KJ/mol、10KJ/mol、32.6KJ/mol和35KJ/mol.建议气体分离膜在室温操作而渗透汽化膜在较高温度操作。
The composite membranes which were made of polydimethyl siloxane and polyropylene porous membrane were used to separate O_2, N_2 and the mixture of water-ethanol by pervaporation respectively. The results showed, when the membrane was thinner the selectivity of the membrane maintained no obvious change for gas, but had great decrease for pervaporation. It suggests, even though both membrane separation of gases and pervaporation separation of liquids follow 'solution diffusion' mechanism, the respective contrabution of solution and diffusion to selectivity for gas mixture or liquid mixture is different in degree.The permeation activation energy for oxygen, nitrogen, ethanol and water are 6. 7 KJ/mol, 10KJ/mol, 32. 6KJ/mol and 35KJ/mol respectively. It was suggested that the operation should be in room temperature for GSM and in higher temperature for PVM.
出处
《膜科学与技术》
CAS
CSCD
1992年第1期32-36,共5页
Membrane Science and Technology
基金
国家自然科学基金
