密胺苯二醛多孔聚合物/聚二甲基硅氧烷混合基质膜的制备及气体分离性能

以溶液复合成膜法制备了密胺苯二醛多孔聚合物(MA)/聚二甲基硅氧烷(PDMS)混合基质膜,利用扫描电镜(SEM)表征了混合基质膜的形貌。考察了不同MA用量下MA/PDMS混合基质膜的气体分离性能,结果表明,MA的加入可以在提高PDMS膜渗透系数的同时提高CO_2气体分离选择性;随着混合基质膜中MA含量的增加,混合基质膜的渗透系数均明显提高,气体分离选择性则先增大后减小。双组分混合气体分离测试结果表明,MA/PDMS(1.2%(w,质量分数))混合基质膜对CO_2/N_2和CO_2/CH_4的分离选择性分别是19.2和6.0,CO_2的渗透系数达到8100Barrer,均高于纯PDMS膜。MA/PDMS(1.2%(w))混合基质膜对CO_2/N_2混合气的分离性能突破了Robeson上限。

Preparation and Gas Separation Properties of Melamine-Phthalaldehyde Porous Polymer/Polydimethylsiloxane Mixed Matrix Membrane

Melamine phthalaldehyde porous polymer (MA)/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) were prepared using the solution casting method. The morphology of the membranes was examined using a scanning electron microscope (SEM). The gas separation performance of the prepared MA/PDMS MMMs with different MA contents was investigated. The results indicate that the incorporation of MA could improve the permeability/selectivity combinations of the PDMS membrane. On increasing the MA content, the permeability of the membranes increased, whereas, the separation selectivity increased at first and then decreased. The binary gas permeation test results showed that separation selectivities of 19.2 and 6.0 for CO₂/N₂ and CO₂/CH₄, respectively, were achieved on the MA/PDMS (1.2% (w, mass fraction)) membrane. Additionally, the CO₂ permeability reached up to 8100 Barrer, much higher than that of the pure PDMS membrane. The MA/PDMS (1.2% (w)) MMM surpasses the Roberson upper bound for CO₂/N₂ separation.