Preparation techniques for immersion precipitation

Most of the membranes in use today are phase inversion membranes obtained by immersion precipitation. Phase inversion membranes can be prepared ftom a wide variety of polymers. The only requirement is that the polymer must be soluble in a solvent or a solvent mixture. In general the choice of polymer does not limit the preparation technique. 

The various techniques will be described very schematically here so that their characteristics may be understood. Pretreatment and post-treatment will not be considered because they are very specific and depend on the polymer used and on the type of application. Basically, the membranes can be prepared in two configurations flat or tubular. 

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