Fabrication and characterization of electrochemical membranes

Membrane separation technology is of high research interest owing to its energy efficiency and environmental friendliness. Electro-membranes have gained popularity in the last decade due to their ability to overcome critical membrane drawbacks such as permeability, selectivity, and fouling. In particular, the electrospun electrochemical membranes (ECMs) have shown desirable surface areas, uniform porosity, and so on, which improve permeability and functionalization for enhanced pollution rejection in water treatment. In this chapter, the fabrication process of the most commonly utilized ECM for water treatment is discussed. The fabrication techniques, properties, processes, and other important parameters, such as material selection, nanomaterial incorporation, surface modification methods, and so on, that distinguish the fabrication routes and their challenges are discussed. The dispersion and incorporation of nanomaterials in mixed matrix ECMs to develop highly enhanced composite membranes have opened novel routes for ECM fabrication. Aside from the polymeric and ceramic, ECMs have been widely fabricated via electrospinning, sintering, phase inversion, the sol–gel method, and so on. The other ECMs, such as ion-exchange membranes and electrocatalytic membranes, are also either fabricated via sol–gel, dip coating, sintering, and so on, or a combination of the two or more techniques that provide surface modification, thus improving the membrane functionality. Some of these integrated electro-membranes have been tested using synthetic wastewater or low- to medium-strength wastewater in lab-scale investigations only. The practicality of these investigations is still debatable. The challenge, therefore, is the scale-up of these fabrication processes and the application of the ECMs for the treatment of wastewater with higher pollutant strengths. Therefore, to ensure progress in the production of ECMs, advancements should focus not only on the fabrication of superior composite electro-membranes but also on the fabrication of inexpensive, scalable electro-membranes with tunable physicochemical properties.