Carbon nanotube/polyaniline nanofiber ultrafiltration membranes

Abstract

Development of electro-ultrafiltration membranes is an attractive target. We report electrically conducting ultrafiltration membranes by blending single-walled carbon nanotube/polyaniline (SWCNT/PANi) nanofibers into a polysulfone (PSf) matrix. By selecting the amount of nanofibers and applying a flash welding technique, the chemical structure, porosity, thermal stability, conductivity, hydrophilicity, permeability, and bovine serum albumin (BSA) rejection of these composite ultrafiltration membranes can be controlled. Addition of SWCNT/PANi nanofibers to the composites enhances the initial water permeability by 2.5–7.3 times and increases the hydrophilicity, and maintains considerable rejection of BSA from 39.8–73.7%. An electrical conductivity between 0.1 and 3.4 × 10⁻⁶ S cm⁻¹ can be maintained over a broad pH range from 0.52–10.2. By regulating the flash welding intensity, the conductivity, permeability, and BSA rejection can be enhanced up to 600, 2, and ∼1.5 times, respectively.