Selective removal of cationic organic dyes via electrospun nanofibrous membranes derived from polyarylene ethers containing pendent nitriles and sulfonates

Nanofibrous membranes showing selective separation of certain dyes out from multiple organic mixtures are of great importance for many advanced applications. Although various strategies including mixed-matrix-membrane or elaborately designed surface modification have been reported for preparation of these advanced membranes, they are still limited in terms of tedious experimental work and questionable long-term stability. Herein, we have designed and synthesized a range of super-engineering polyarylene ethers containing pendent nucleophilic nitriles and negatively charged sulfonate groups, which have been further processed into nanofibrous membranes (NFM) via the one-step electrospinning technique. Thanks to the presence of high density of surface active binding sites, the electrospun polymeric nanofibers exhibited a high adsorption capacity of 796.25 mg/g for cationic organic dye of methylene blue. More importantly, the optimized polymeric NFM allows rapid selective removal of cationic dyes from their mixtures with other dyes molecules, and the removal efficiency of cationic dyes arrives up to 99% even after eight separation-regeneration cycles. Due to their facile fabrication, highly selective purification feature as well as good recyclability, the protocol revealed in this work would open new way for fabrication of advanced separation membranes for wastewater purification.