A review on recent progress in ultrafiltration membranes.

Since the application fields of ultrafiltration (UF) are expanding very rapidly, an UF membrane must have various kinds of characteristics. In this article, the UF membranes developed recently are reviewed from the literatures published after 1980.Recently, two kinds of heat-resistant UF membranes have been developed by using polyether-sulfone as membrane material. In particular, the commercially available DUS-40 membrane resists the sterilization by pressurized hot water at 128 °C.Several kinds of solvent-resistant UF membranes have been developed by using various types of polyimide. One of these membranes has already been commercialized.As the highly functional UF membrane, various kinds of negatively and positively charged UF membranes have been developed. Applications of the charged UF membranes are still under development.Many types of UF membranes have also been developed by using various kinds of polymers.Inorganic materials were also used in order to make UF membranes having large heat- and solvent-resistance.Several kinds of porous ceramic membranes and porous glass membranes have, already been commercialized. Many of these membranes have pores whose diameters are 0.2-10, μm, and are mainly used as a microfiltration membrane.Porous aluminium membranes are now under developing.Dynamically formed inorganic UF membranes have been developed by using several kinds of inorganic colloids.