OPEN-PORE SINTERED GLASS-CERAMICS AS CARRIER MATERIAL FOR BIOTECHNOLOGICAL USE

Open-pore carriers with defined open porosity up to 45 % for biotechno logical use were manufactured by sintering and crystallization of glas s powders of cordierite stoichiometry. The stop of the shrinkage cause d by a surface crystallization of the glass (''sinter blockade'') is u tilized to stabilize a desired pore volume without filler or foaming a ids. Glass powders of the stoichiometric composition of cordierite (2M gO . 2Al(2)O(3) . 5SiO(2)) with different grain size distributions wer e used as starting materials. The efficiency of the sinter blockade an d thereby the stabilized porosity of the resulting compact mainly depe nds on the surface nucleation density at the single glass particles wh ich can be adjusted by powder processing. Furtheron, the chosen grain size distribution of the glass powders and the sintering process param eters (heating rate, temperature, heating time) are important factors to control the sintering behaviour. Samples of carrier bodies produced by this way are tested and evaluated quantitatively as carriers for b iofilms in a biotechnological process for decomposition of pollutants in a synthetic model waste water system.