Conductive CNT/nanofiber composite hollow fiber membranes with electrospun support layer for water purification

Hollow fiber membranes (HFMs) have been extensively used to alleviate the crisis of water resources because of their large contact area per unit volume. However, developing high permeability and mechanical strength HFMs remains a great challenge. In this study, we design a novel carbon nanotube (CNT)/nanofiber composite hollow fiber membrane (CNC-HFM) that possesses significant advantages of permeability and mechanical strength. Specifically, the pure water flux and Young's modulus of CNC-HFMs are 7.3 and 12.7 times higher than the commercial polyacrylonitrile HFMs with comparable pore size, respectively. The outstanding merits derive from the continuous interlaced nanofiber-scaffold structure of electrospun nanofiber support layer and crosslinked CNT separation layer, with low-tortuosity membrane pore, high porosity and mechanical strength. In addition, benefiting from the good electrical conductance of CNT separation layer, CNC-HFMs can exhibit a mitigation of membrane fouling and an improvement of separation performance during surface water treatment under electro-assistance. The approach of constructing asymmetrical HFMs with electrospun nanofibers as the support layer and CNTs as separation layer provides unique thoughts for the design and manufacture of efficient separation membranes.