Polymerics and ceramics membrane materials
Polymerics and ceramics membrane materials:
Polymeric membrane materials. All polymers can be used as barrier or membrane material but the chemical and physical properties differ so much that only a limited number will be used in practice. A classification will be made between the open porous membrane, which are applied in micro filtration and ultrafiltration and the dense non porous membranes applied in gas separation and pervaporation. For the porous micro filtration / ultrafiltration membranes the choice of the material is mainly determined by the processing requirements, fouling tendency and chemical and thermal stability of the membrane. For the dense non porous membrane, the choice of the material directly determines the membrane performance Eg. Polyacrylonitrile, High density) polyethylene, Polytetrafluoroethylene
Ceramic membrane materials: They are inorganic membranes formed by the combination of a metal with nonmetal in the form of an oxide, nitride or carbide. They are having good thermal and chemical resistance. Their melting points are very high. The high temperature resistant makes these materials very selective for gas separation at high temperatures. They can be used at any pH and in any organic solvent. It is easy to clean and all kinds of cleaning agents can be used, allowing strong acid and alkali treatment. Lifetimes of inorganic membranes are greater than that of polymeric membranes.
Eg Aluminium oxide / Alumina, Silicon carbide, Titanium dioxide / Titania