Abstract:

The hollow polypyrrole nanoparticle with porous shell was incorporated into poly(ethylene oxide) monomer to fabricate the mixed matrix membrane by free radical polymerization. Morphology of the membranes showed the polymeric filler had good interfacial compatibility with the polymeric matrix without obvious defect. The results showed that the gas permeability of membranes increased at first and then decreased as the filler loading increased, while the permselectivity of CO₂/N₂ decreased_{andthat of CO2/CH4 maintained constant basically. The research showed that the diffusion coefficients decreased due to the blockage of the pore in shell of nanoparticles by polymeric matrix, the improvement of the gas permeability was mainly contributed by the improvement of the solubility coefficient, which also affected the solubility selectivity and then the permselectivity. The optimum nanoparticle loading was around 0.5%. In this case, the permeability of CO2 was about 6.5×10^-11 cm³?cm?cm^-2?s^-1?Pa^-1 (31% higher than the pristine polymeric membranes), while the permselectivity of CO2/N2 was about 30 (34% lower than that of the pristine polymeric membranes) and the permselectivity of CO2/CH4 was about 14 without significant sacrifice. The result showed the polypyrrole nanoparticles with porous shell was potential for application in CO2/CH4 separation.}

Key words: carbon dioxide, nanoparticles, membranes, hollow particles, mixed matrix

摘要：

采用壳层具有介孔结构的聚吡咯中空纳米微球作为填料，和聚氧化乙烯单体共混自由基聚合制备了混合基质膜。结果表明，聚吡咯微球与基质相容性较好，未见明显团聚现象和缺陷。混合基质膜的渗透系数随填料含量的增加先增大后减少，在0.5%处达到最大值，CO₂渗透系数增长31%；CO₂/N₂分离系数有所降低，CO₂/CH₄分离系数则变化不大。研究表明，由于聚合物链段对微球壳层的介孔填充，气体在膜内的扩散系数不升反降，渗透系数的提高主要是由于溶解度系数的变化，而这也导致了溶解选择性的变化，进而影响了分离系数。

关键词: 二氧化碳, 纳米粒子, 膜, 中空粒子, 混合基质