| abstract |
A filter media system, which is capable of operating in the microfiltration regime, offers: low cost, durability, high temperature and chemical resistance, no particulation, mechanical strength, separation efficiency, and biocompatibility. A filter media system is comprised of a carbon or ceramic composite substrate (1) which contains a carbon or ceramic matrix reinforced with carbon or ceramic fibers. The composite has an array of carbon or ceramic fiber whiskers (2) grown onto its surface or in its bulk. A process is provided for manufacturing the filter media system wherein a carbon fiber is disposed in a matrix deposited by a CVI or LPI process, at temperatures of about 900 to about 1200 °C to achieve a weight gain of about 10 to 200 % (the ceramic matrix is deposited by a CVI process from an aqueous slurry or by use of a pre-ceramic polymer). This composite is treated with an aqueous solution of metal catalyst salt and is then heated in hydrogen at elevated temperatures to reduce the metal salt to metal. Whiskers are then grown on the surface or in the bulk of the catalyst deposited composite such as by decomposition of methane gas using metal catalyzed chemical vapor deposition (CVD). |