NANOSCALE MATERIALS IN WATER PURIFICATION

Today, nanosized structures have a remarkable impact on technological advancements in biomedical, bioengineering, and environmental applications. Electrospinning is an efficient and versatile technique for the fabrication of nanostructures made of fibers with a high surface-to-volume ratio. This technology produces nanofibers starting mostly from solutions of a wide variety of polymers via a proper polymer-solvent selection. The extreme elongation and narrowing of the fiber occur because of electrostatic repulsive forces on the charged jet. By fine-tuning the processing variables, it is possible to control the fiber diameter and consequently the mat porosity. Furthermore, depending on the nozzle structure and collecting mode, it is possible to realize fibers with various morphologies, thus adding an extra level of complexity to the nanostructured mat. The advantages of using nanofibrous structures in filtration media are related not only to their physical features but also to the possibility of functionalizing their surface through polymer chemistry, blending, and nanofiller incorporation. In this frame, electrospinning gives the possibility to incorporate active molecules or functionality directly during processing, thus tailoring the properties of the electrospun membrane according to the specific requirements. Electrospun nonwoven textile shows intriguing features for many potential applications where a massive surface area and specific functionalities are required as high-efficiency filter media. In this chapter, we provide an overview of current studies on the use of electrospun nanofibers to realize membranes for water purification; different strategies adopted to improve the electrospun membrane efficiency in terms of having a better capacity to remove pollutants are described.