Effect of operating parameters on pure and mixed gas permeation properties of a synthesized composite PDMS/PA membrane
Effect of operating parameters on pure and mixed gas permeation properties of a synthesized composite PDMS/PA membrane
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DOI：
10.1016/j.memsci.2009.07.015
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发表时间：
2009-10
影响因子：
9.5
通讯作者：
M. Sadrzadeh;K. Shahidi;T. Mohammadi
中科院分区：
文献类型：
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作者：
M. Sadrzadeh;K. Shahidi;T. Mohammadi
合成了聚二甲基硅氧烷（PDMS）/聚酰胺（PA）复合膜，研究了纯气和混合气中C3 H8、CH 4和H2的吸附、扩散和渗透行为。纯气体实验表明，增加跨膜压可增加较重气体C3 H8的溶解度、渗透率和扩散系数，而对较轻气体CH 4和H2的溶解度、渗透率和扩散系数没有影响或略有降低。在混合气体实验中观察到完全相反的行为（除了C3 H8和CH 4溶解度），由于在塑化聚合物基质中的竞争吸附和扩散。温度对纯气体和混合气体的渗透性能有相似的影响。正如预期的那样，在橡胶膜如PDMS中，更多可冷凝气体的渗透率值随着温度的升高而降低，而永久性气体的渗透率值随着温度的升高而增加。对纯气体和混合气体实验中渗透率、溶解度和扩散系数的线性压力依赖性（斜率m、n和q）和Van 'tHoff-Arkius型温度依赖性（活化能Ep、Δ H和艾德）进行了估算和讨论。在混合气体实验的情况下，增加进料中的C3 H8浓度导致所有组分的溶解度、渗透率和扩散率增加，这是由于C3 H8诱导的PDMS膜的溶胀。实验结果表明，合成的PDMS/PA膜用于从永久性气体中分离有机蒸气的能力。
A composite polydimethylsiloxane (PDMS)/polyamide (PA) membrane was synthesized and sorption, diffusion and permeation of C3H8, CH4and H2were studied both in pure and mixed gas experiments. Pure gas experiments showed that, increasing transmembrane pressure increases solubility, permeability and diffusivity coefficients of heavier gases, C3H8, while does not affect or slightly decreases those of lighter ones, CH4and H2. Exactly opposite behavior was observed in mixed gas experiments (with the exception of C3H8and CH4solubility) due to the competitive sorption and diffusion in the plasticized polymer matrix. Temperature was realized to induce similar effects on permeation properties of pure and mixed gases. As expected, in rubbery membranes such as PDMS, permeability values of more condensable gases decrease with increasing temperature, whereas those of permanent gases increase. Parameters indicating linear pressure dependence (slopes m, n and q) and Van’t Hoff–Arrhenius type temperature dependence (activation energies Ep, ΔHsand Ed) of permeability, solubility and diffusivity coefficients in both pure and mixed gas experiments were estimated and discussed thoroughly. In the case of mixed gas experiments, increasing C3H8concentration in the feed led to increasing solubilities, permeabilities and diffusivities of all the components due to the C3H8-induced swelling of the PDMS film. Experimental results demonstrated ability of the synthesized PDMS/PA membrane for separation of organic vapors from permanent gases.