Fluoropolymers for oil/water membrane separation

Oily wastewater pollution is responsible for affecting drinking water, groundwater resources and crop production, endangering aquatic resources and human health, polluting the atmosphere, and destroying the natural landscape. Among the treatment techniques of oily wastewaters, membrane separation processes are preferred because they possess high oil removal efficiency and relatively facile operational processes for any kind of emulsions, especially surfactant-stabilized emulsions. The success of filtration is also due to the advances made in the development of special wettable materials: specifically, two families of materials are suitable for selective oil/water separation, that is, hydrophobic and oleophilic materials, and hydrophilic and oleophobic materials. Fluorinated polymers, besides suitable wettabilities, have high chemical resistance and thermal stability, thus becoming preferred materials for filtration membranes. The chapter describes the oil/water separation method of polymer membranes, in particular showing the importance of wettability. Then it illustrates the preparation and use of fluoropolymer membranes, detailing the materials they consist of, their properties, their structure, and obviously their efficiency in oil/water separation.