A ceramic membrane filter was developed by depositing ultrafine powders ont
o a porous substrate. The powders, having an average particle size of tens
of nanometers, were produced by a newly developed technology, pulsed wire d
ischarge: The carrier gas was pumped through the porous substrate, which ha
d been heated to 500 degrees -700 degreesC, so that the powders could be si
ntered on the substrate surface, resulting in a membrane filter. Gas separa
tion experiments were conducted using this filter. The experimental results
showed a ratio of gas permeation very close to that given by the Knudsen f
low.