高性能PAN-MWCNTs/PEI复合正渗透膜的制备

Preparation of High-Performance PAN-MWCNTs/PEI Composite Membrane for Forward Osmosis

本研究设计并制备了一种新型复合正渗透膜,在致密聚酰胺层(PA)和静电纺丝聚丙烯腈(PAN)多孔支撑层之间敷设酸化多壁碳纳米管与聚乙烯亚胺(MWCNTs-PEI)交联的中间层。中间层的存在缩小了支撑层的孔径,为PA层的生长提供了更好的平台,有助于抑制汲取溶质的反向扩散。PEI的加入不仅可以将MWCNTs牢固地结合在支撑层上提高中间层稳定性,而且可以与TMC部分结合使得PA层更加稳定。结果表明,当中间层负载量为0.849 g/m,纯水为原料液,1 mol/L NaCl为汲取液时,FO和PRO模式下水通量分别为36.23±1.81、42.06±2.10 L/(m^(2)·h),反向盐扩散通量分别为11.66±0.58、12.20±0.43 g/(m^(2)·h)。良好的整体性能表明,酸化多壁碳纳米管与聚乙烯亚胺交联形成的稳定中间层为研究和制备高性能正渗透膜提供了一条可行的途径。

In this study,a novel composite forward osmosis membrane was designed and fabricated by laying an interlayer between a dense polyamide(PA)layer and a porous support layer of polyacrylonitrile(PAN)electrospinning nanofiber membrane.The interlayer was an acidified multiwalled carbon nanotube crosslinked with polyethyleneimine(MWCNTs-PEI).The presence of the interlayer reduces the pore size of the support layer,providing a better platform for the growth of the PA layer and helping to inhibit reverse diffusion of the absorbed solute.The addition of PEI can not only firmly bind the MWCNTs on the support layer to improve stability of the interlayer,but also partially bind the TMC to make the PA layer more stable.The results showed that when the interlayer load is 0.849 g/m^(2),pure water is the feed solution,and 1 mol/L NaCl is the draw solution,the water fluxes in the FO and PRO modes were 36.23±1.81 L/(m^(2)·h)and 42.06±2.10 L/(m^(2)·h),respectively.The reverse salt fluxes were 11.66±0.58 g/(m^(2)·h)and 12.20±0.43 g/(m^(2)·h),respectively.The overall performance showed that the stable interlayer formed by the acidified MWCNTs crosslinking PEI,provided a feasible way to study and prepared the high performance forward osmosis membranes.