磁场作用下磁性碳纳米管填充自具微孔聚合物膜的氧氮渗透性能

O_2/N_2 permeability properties of magnetic CNT filled PIM membranes under action of magnetic field

采用原位生长法合成磁性碳纳米管(Fe_3O_4-CNT),并将其填充到自具微孔聚合物PIM-1中,通过溶剂挥发法制备PIM-1/Fe_3O_4-CNT混合基质膜,考察了外加磁场作用下Fe_3O_4-CNT质量分数和磁场强度对混合基质膜的理化结构及其氧氮渗透性能的影响。结果表明,磁性碳纳米管与PIM-1基体间的相互作用增强,磁性碳纳米管在膜中的分散状态得到明显改善,同时混合基质膜的力学性能也得到了提高。Fe_3O_4诱导磁场和CNTs中空结构的协同作用显著提高了混合基质膜的氧氮渗透性能,当Fe_3O_4-CNT质量分数为1.5%时,PIM-1/Fe_3O_4-CNT混合基质膜的O_2渗透系数为602 Barrer,O_2/N_2选择性达到了4.32,与纯PIM-1膜相比分别提高了76%和27%;外加磁场强度增大,混合基质膜的O_2渗透系数和O_2/N_2理想选择性同时提高。

Magnetic Fe3O4-CNTs are synthesized via in-situ growth method and are then filled into polymers of intrinsic microporosity（PIM）. PIM-1/Fe3O4-CNT mixed matrix membranes（MMMs） are prepared by solvent evaporation method.The influences of the mass fraction of Fe3O4-CNT and the intensity of magnetic field on the O2/N2 permeability properties and physicochemical character of MMMs are investigated under action of outer magnetic field.The results show that the interaction between Fe3O4-CNT and PIM-1 matrix is enhanced,the dispersive situation of magnetic Fe3O4-CNT within membranes is improved significantly and the mechanical properties of MMMs are increased. The synergistic effect between the induced magnetic field of Fe3O4 nanoparticles and the hollow structure of CNT-COOH can increase greatly the O2/N2 permeability of MMMs. When the mass fraction of Fe3O4-CNT is 1. 5% in MMMs,the O2 permeability coefficient and O2/N2 selectivity of PIM-1/Fe3O4-CNT MMMs can reach 602 Barrer and 4. 32,respectively,which are 76% and 27% higher separately than pure PIM-1 membrane. Both O2 permeability and O2/N2 selectivity of MMMs increase with the enhancing outer magnetic field.