Phase inversion is a process where one material from a liquid-phase is transformed together with the aid of a polymer that is managed into a solid phase. They are the following; precipitation in the vapor stage, permitting precipitation with all the help of evaporation that is controlled, phase separation which can be thermally induced and finally precipitation that is immersion. Among these four methods that are fundamental, immersion precipitation is one that is mainly employed. The four simple methods of phase inversion are described in more detail the following. A solvent -polymer mixture emerge a vapor atmosphere where there exists a nonsolvent which is saturated with the solvent and is placed on a movie. The diffusion of the nonsolvent to the cast movie types a membrane consequently. The result of this process is a porous membrane. The other phase inversion technique which is the precipitation by evaporation that is controlled consists of a polymer which can be dissolved in a solvent plus a nonsolvent combination. The large volatility results in the evaporation of a membrane that was skinned as well as the solvent are formed as a result. Thermally induced phase separation means of of phase inversion makes usage of a solitary or a mixture of polymer options that were solvent which is cooled down in order to achieve phase separation stage. It is as the membranes are formed because of the solvent evaporation in this procedure, a method which is often employed in the planning of synder membranes. The last means of of phase inversion is the immersion precipitation and it is the most generally used one among the four methods. In this technique, the blend of phase separation and mass-transfer processes affects the framework of the membrane that is certainly formed. The polymer that’s used in this method have to be soluble in a mixture.