Abstract

Membrane is a barrier that allows the selective transport of materials. Porous membranes may be symmetric or asymmetric in nature. Based on the pore size, these membranes may offer applications such as nanofiltration, microfiltration, ultrafiltration, or reverse osmosis. Further, on the basis of composition, membranes may be organic (polymeric) or inorganic in nature. Polymeric organic membranes may be composed of synthetic or natural polymers. Polymers such as polyethersulfone, polyamide, polyimide, and polytetrafluoroethylene can be used in the preparation of membranes. Various methods such as electrospinning, phase inversion, track etching, film stretching, and melt pressing can be adopted for preparation of membranes. These membranes are available in different modules such as plate and frame module, tubular module, spiral wound, hollow fiber, and rotating disc. This entry thus discusses various types of membranes, their preparation, modules available, and their analysis.