Anti-fouling/wetting electrospun nanofibrous membranes for membrane distillation desalination: A comprehensive review

The membrane distillation (MD) process has been identified as one of the most promising technologies in seawater desalination and wastewater treatment due to its lack of a salinity limit, low operating pressure, and 100 % salt rejection. Electrospinning provided a simple technique for fabricating a hydrophobic nanofibrous membrane for the MD process. Electrospun nanofibrous membranes have several advantages, including narrow diameter, large surface area per unit mass, extraordinary porosity, high hydrophobicity, high gas permeability, and smaller interfibrous pore size. Despite several advancements and benefits, hydrophobic and superhydrophobic electrospun membranes are still sensitive to wetting and fouling issues due to the presence of low surface tension contaminants (surfactants) and hydrophobic contaminants (foulants) in the feed water. To overcome these challenges, omniphobic nanofibrous membranes that repel both water and low surface tension solutions are required, extending the membrane's lifespan. This review discusses the fundamental details of the MD process and electrospinning configurations used to fabricate membranes for MD applications, as well as the desirable properties and advantages. In order to demonstrate how electrospun hydrophobic/superhydrophobic/omniphobic membranes improved anti-fouling and anti-wetting properties, year-by-year research efforts are also compiled. Finally, the challenges and potential future strategies for electrospun nanofibrous membranes are discussed.