Two-nozzle electrospinning of SPSF-PEI/PES composite membranes with anti-swelling properties and efficient adsorption of anionic dyes

Swelling of membranes can lead to reduced mechanical strength and deformation of the pore structure. The traditional cross-linking modification method still suffers from the disadvantages of solvent residue and complex operations. This study proposed a stability-enhanced sulfonated polysulfone (SPSF)-polyethyleneimine (PEI)/polyethersulfone (PES) composite membrane through a simple and effective strategy using a two-nozzle electrospinning technique. The SPSF/PES and PEI/PES jets interweave in the electric field via electrostatic interactions or hydrogen bonding to form a composite membrane, which demonstrated a tensile strength increase of over 85.2% alongside a swelling ratio reduction exceeding 51.4% compared with the PEI/PES membrane. The adsorption of SPSF-PEI/PES composite membranes for Acid Fuchsin follows a pseudo-first-order kinetic model. Besides, the adsorption capacities of the optimal composite membrane for Acid Orange 7 (AO7), Acid Fuchsin (AF), Congo Red (RB), and Methyl Blue (MB) reached 267.9, 320.2, 428.4, and 439.5 mg/g, respectively. This study proposed a simple and effective strategy for preparing electrospun membranes with improved swelling properties and high-efficiency anionic dye adsorption. • Two-nozzle electrospinning was used to prepare an anti-swelling SPSF-PEI/PES membrane. • The resultant composite membranes show excellent anion adsorption performance. • The composite membrane achieves over 51.4% swelling reduction. • The composite membrane maintains superior dye removal in simulated wastewater.