Pervaporation and Evapomeation with Si-Containing Polymers

Silicone rubber is the benchmark membrane material for organic‐air separation as well as for organic‐water pervaporation (PV). This chapter introduces Si‐containing polymer membranes in PV. Novel materials for separation membranes are selected based on development of systematic structure‐property relationships in polymers to provide membranes with enhanced permeability and selectivity, ease of membrane preparation, and their stability under permeation conditions, such as pH, temperature, and pressure. PV is applied as the chosen membrane separation technique for the separation of water–organic, organic–water, and organic–organic mixtures. A novel membrane separation technique known as “evapomeation (EV)” makes use of the advantages of PV, but reduces the negative effects of swelling on membrane performance. Evapomeation was coined as a combination of the evaporation of the feed liquid, the permeation of the penetrant through the membrane, and its evaporation into the vapor phase based on the former parts in the three basic steps of the process.