PDMS磁性膜的制备及其对O2/N2分离性能研究

Preparation and O2/N2 Separation Performance of PDMS Magnetic Mixed Matrix Membrane

以聚二甲基硅氧烷(PDMS)为聚合物基体,以Fe3O4和乙烯基三乙氧基硅烷修饰四氧化三铁(VTES@Fe3O4)为磁性基元,采用溶剂挥发法制备了PDMS/Fe3O4、PDMS/VTES@Fe3O4磁性混合基质膜。研究了磁性粒子添加量以及界面空隙在有无磁场存在时对磁性混合基质O2/N2分离性能的影响。结果表明,随着VTES@Fe3O4含量的增加,该磁性膜O2/N2选择性呈先增后减的趋势,磁场的存在使得O2/N2选择性进一步增加。磁场作用下,Fe3O4和PDMS之间能形成O2渗透低阻力磁通道的界面空隙,因VTES的引入而消失。当磁性粒子添加量为3.5wt%时,PDMS/Fe3O4磁性膜在磁场作用前后O2/N2选择性增量高于PDMS/VTES@Fe3O4膜(0.3>0.1)。

In this work,Fe3O4 and vinyltriethoxysilane modified Fe3O4(VTES@Fe3O4) were used as magnetic fillers into polydimethylsiloxane (PDMS) matrix, fabricating PDMS/Fe3O4 and PDMS/VTES@Fe3O4magneticmixed matrix membranes (MMMs) by solvent evaporation methods,respectively.The effect of magnetic fillers contents and interfacial compatibility between magnetic fillers and polymer matrix on O2/N2 separation performance was investigated..The results indicated that with the increase of VTES@Fe3O4 contents,O2/N2 selectivity of the magnetic MMMs increased at first and then decreased,and external magnetic field could enhance the selectivity of O2/N2.The inevitable interfacial defects in PDMS/Fe3O4 MMMs can be considered to be the transport channel of O2 with low resistance under external magnetic field,while this transport channel disappearing due to the containing VTES.When the magnetic fillers loading was up to 3.5 wt%,the O2/N2 selectivity of PDMS/VTES@Fe3O4 and PDMS/Fe3O4 MMMs increased by 0.1 and 0.3 under external magnetic field,respectively .