A novel method, supersonic viral impaction, is being investigated to separate and collect fine, solid particles from gases. The main advantages of the method are: separation of particles from hot, chemically aggressive, condensable carrying gases while preserving the particles from contamination by the carrying gas; reduction in size and complexity compared to cornpeting separation techniques such as filtration; and separation of smaller particles than conventional subsonic impaction techniques. Researchers are demonstrating the feasibility of the method by separation and collection of 1-10 @m diam solid particles @rom supersonic air flows, The research is developing an improved particle separation and classification method which extends both the range of particle siies which can be handled, and the conditions under which such separations can be carried out. Applications in combustion synthesis of novel materials, particle size classifiers, and waste effluent cleanup are being explored.The potential commercial application as described by the awardee: The project develops improved means of particle separation from gases which would be useful in combustion synthesis, aerosol size classification, and waste effluent cleanup.