Structural and chemical properties of glass capillary membranes and their use in protein separation

Abstract

Inorganic materials for membranes become increasingly interesting with respect to applications in pharmaceutics, medicine, biotechnology and other fields where high chemical resistance is mandatory. Among the different kinds of membrane materials, BIORAN® porous glass can be seen as a widely variable and adaptable material because of its broad range of pore sizes and of its changeable surface polarity. In recent years porous glass applications for seawater desahnation, emulsion splitting, hemofiltration, diafiltration, milk concentration and cascade plasmapheresis were evaluated. Ultrafiltration and/or microfiltration in the fields of biotechnology, medicine and pharmaceutics are mainly demanded for the separation, concentration and purification of proteins. Because of only small differences in physical properties like molecular size etc., the individual chemical properties as well as process parameters must be exploited to get satisfactory results. The structure and the properties of porous glass membranes are largely independent from external influences. This leads to cleanable, even heat-sterilizable membrane modules. BIORAN® porous glass membranes are produced as capillaries showing excellent mechanical stability even at high pressures. Due to narrow pore size distribution and variable surface properties they may be tailored to certain applications.