Abstract
This chapter discusses organic–inorganic membranes. The use of organic–inorganic materials for membranes is very attractive as it provides the possibility of achieving synergetic effects on permeability and selectivity, introducing new functionalizations, and improving mechanical and thermal stability. The chapter summarizes different possibilities of combining organic and inorganic phases or segments for membrane preparation. A network of organic and inorganic segments can be prepared by reacting epoxy-functionalized silanes and diamines containing long ethylene oxide segments. The selectivity for CO2 can be enhanced by the ethylene oxide segments. The addition of tetraethoxy silane to the reaction mixture increases the content of the inorganic phase in the membrane and minimized excessive swelling. The most representative examples of introducing permeable inorganic fillers in a polymeric matrix for separation purposes are mixed matrix membranes. The possibility of incorporating zeolites into a flexible organic polymer matrix enables the combination of the superior gas selectivities of these molecular sieves with the processibility of polymeric membranes.