Ultrathin nanoporous membrane fabrication based on block copolymer micelles

As researchers can control the nanostructure of the nanoporous membrane based on block copolymer precursors, it is considered to be an ideal device for separation and purification. However, the challenge still remains to make ultrathin, economic, nanopore sized and charged isoporous membranes without post-treatment. Hence, a simple, energy saving and sacrificial layer free technique was adopted to bridge the gap between the uniformly spread PS-b-PAA nanospheres and the ultrathin, negatively charged nanoporous membrane. The flux of the membrane is as high as 350 L m⁻² h⁻¹ bar⁻¹, while the effective pore size is only ca. 8 nm. It can separate not only the nanoparticles based on their size differences, but can also separate similarly sized proteins based on the charge differences efficiently. Moreover, nanofibers and lamellae formed nanoporous membranes have now been fabricated. The effective pore size can be customized, and can even be smaller than 1.5 nm for the lamellae formed membrane.