A novel blending nanofibrous membrane of Poly(ionic liquid) for efficient and fast adsorption of ReO4−

Efficient recovery of rare scattered metal Re(VII) from various resources is a prerequisite due to its important application. Herein, a type of novel nanofibrous membrane, 0.4P(Ph-3MVIm-Br)-3PVP/2TPU, is successfully prepared by electrospinning, where poly(ionic liquid) P(Ph-3MVIm-Br) is incorporated and could supply more adsorption sites. Meanwhile, PVP (polyvinyl pyrrolidone) and TPU (thermoplastic polyurethane) ensured the water flux and the structural stability of the membrane. The nanofibrous membrane exhibited a high adsorption capacity for ReO4−, which can reach 128 mg g−1 at pH 5. Its water flux is as high as 433 L m−2 h−1 at 0.4 g of poly(ionic liquid) addition, membrane thickness of 20 μm, and pressure of 1 bar. Furthermore, 0.4P(Ph-3MVIm-Br)-3PVP/2TPU nanofibrous membrane can remove 91.7% of ReO4− within 30 min. After 9 times recycling, the adsorption efficiency of the membrane can still maintain more than 90%. Dynamic ReO4− removal with 0.4P(Ph-3MVIm-Br)-3PVP/2TPU after one cycle was accomplished with a breakthrough volume of 24 mL ReO4− solution (feed 10 mg L−1, 100 mg membrane). The exchange of ReO4− and Br− of poly(ionic liquid) mostly promote the adsorption of ReO4−. Moreover, the structure of the membrane has excellent selectivity, mechanical performance, strong acid and alkali resistance stability, which endow the membrane easy to operate in practical applications.