High performance nanofiltration membrane using self-doping sulfonated polyaniline

Herein, an interlayered-enhanced thin film composite (i-TFC) membrane with excellent separation performance was fabricated using self-doping sulfonated polyaniline (SPANI) nanofibers. SPANI nanofibers were synthesized via two kind of sulfonated reagents and used for comparison. Nanofibrous SPANI can generate an excellent interlayer of membrane, which effectively mediates the IP process and promotes the formation of nanostructured polyamide (PA) layers with superior sieving ability. The increase in degree of sulfonation in an interlayer exhibits superior hydrophilicity, which is favorable for the formation of a thinner and defect-free PA layer. The SPANI of high degree of sulfonation also endows the i-TFC membrane with a high water permeance up to 29.35 ± 1.23 L m−2 h−1 bar−1, while maintaining a competitive selectivity of 4.60 for Mg2+/Na+ and 76.01 for SO42−/Cl−, as well as good retention capacities for both Na2SO4 (98.92 ± 0.45%) and MgSO4 (96.21 ± 0.75%).