Multi-layered nanofiber membranes: Preparation, characterization, and application in wastewater treatment

Over the last few decades, micropollutants have been found in the natural surface water, and their presence poses a series of risks to living organisms in the aquatic biotope. Nanofiber membranes have been shown as a new strategy for separating micron-size pollutants due to their tight pore size and high water permeability. Here, a high-efficient multi-layered nanofiber membrane with improved mechanical strength was prepared using the lamination technique. First, polyamide 6 (PA6), polyacrylonitrile (PAN), and polyvinylidene fluoride (PVDF) nanofibers webs were selected. Then nanofibers were laminated on support under various temperatures. Prepared membranes were characterized using SEM, contact angle, pore size, and air permeability tests. The significance of lamination condition on membrane structure was investigated experimentally and statically. The membranes were examined for the treatment of synthetic micropollutants. According to the results, PAN and PA6 nanofiber membranes exhibited high water permeability (over 3000 L/(m ² hbar)) under low pressure, whereas PVDF membranes showed zero permeability. Besides, the prepared nanofiber membranes could separate micropollutants from water with up to 99.91% separation efficiency. Prepared nanofiber membranes hold great promise for practical applications in environmental remediation.