Charged membranes based on spider silk-inspired nanofibers for comprehensive and continuous purification of wastewater

Abstract

Creating a facile and efficient porous membrane for the comprehensive treatment of both insoluble and soluble pollutants from water is of great significance, yet remains challenging. Here, we present a facile strategy to prepare charged nanofibrous membranes assembled from spider silk-like humped SiO2/polyamide 66 (PA66)/polyaniline (PANI) nanofibers by combing Plateau−Rayleigh instability-induced assembly and in situ synthesis. The obtained nanofibrous membranes possess micro/nanostructured surfaces with promising superhydrophilic and underwater superoleophobic property, which are attributed to the synergy of hierarchical roughness and hydrophilic matrix. Combined with the superwettability and the integrated property of submicron pore size, high porosity, and good pore interconnectivity, the membranes can separate various oil-in-water emulsions with a remarkable permeation flux of 5403 l m−2 h−1 and a high separation efficiency (total organic carbon content <5 mg l−1). Moreover, attributed to the Laplace pressure difference and positive potential of the spindle-knotted nanofibers, the biomimetic nanofibrous membranes could remove the filter cake during separation. In addition, the membrane exhibits a remarkable adsorption-reduction capacity of hexavalent chromium. The synthesis of such attractive nanomaterials may provide new insights into the development of multifunctional separation materials for environmental applications.

From 1D Nanofibers to 3D Nanofibrous Aerogels: A Marvellous Evolution of Electrospun SiO2 Nanofibers for Emerging Applications

“…Copyright 2022, Springer Nature. e PA66 coated on SNFs [ 118 ]. Copyright 2021, IOP Publishing Ltd. f CuO nanocrystals decorated SNFs [ 119 ].…”

“…Notably, the BiOBr/PANI heterojunction structure and 3D PANI conductive networks endowed the nanofibrous membrane visible light induced self-cleaning properties. In addition, Zhang et al also prepared another intriguing nanofibrous membrane by constructing periodic knots on electrospun SNFs and further encapsulating the shell of PANI [ 118 ]. The membrane could achieve efficient separation of oil-in-water emulsions, especially due to the synergistic effect of positive charge and spindle-knot structure, and the filter cake could be removed during the separation process, thus guaranteeing the stability of water flux.…”

Effect of Pharmaceutical Compounds (Diclofenac, Ibuprofen, and Erythromycin) on the Heterotrophic Behaviors of Biomass of a Membrane Bioreactor to Treat Urban Wastewater

“…Despite the problems of membrane fouling and high energy costs, it is an efficient technology with pollutant removal efficiencies close to 100% in some cases [40]. Among the pollutants, not only emerging contaminant compounds are covered, but this technology can also be applied to various insoluble (i.e., oils) and soluble (i.e., heavy metals) contaminants [41]. For those types of pollutants (such as oil or petroleum) more specific to industrial and urban wastewater, nanofibrous membranes with visible light-induced self-cleaning capabilities are being developed, with properties such as high porosity, super wettability, and low oil adhesion [42].…”

Broccoli-liked silver phosphate nanoparticles supported on green nanofiber membrane for visible-light driven photodegradation towards water pollutants

“…However, at present, the research on photocatalytic degradation of pollutants is mostly concentrated on powdered nanosized Ag 3 PO 4 photocatalysts, which are difficult to be separated and recycled from the suspension reaction systems [34,35]. It is reported that fixing nano catalysts on appropriate carrier is a good strategy to solve this problem [36][37][38], and some carriers can integrate with adsorption effect, increasing photocatalytic reaction [39,40]. Xiong et al [31] synthesized Ag 3 PO 4 /Fe 3 O 4 /Diatomite composites by the hydrothermal method, and the results showed that the composites have better sterilization effects.…”