Methods for fine particle formation
AssigneeBoard of Regents of the University of Colorado
InventorsRobert E. Sievers, Uwe Karst
Life of this patent
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Abstract
Methods and apparatuses are provided for forming fine particles of a desired substance comprising dissolving said substance in a fluid such as water to form a solution and mixing the solution with a second fluid such as supercritical carbon dioxide which becomes a gas upon rapid pressure release, and with which the first fluid is at least partially immiscible, and releasing the pressure to form an air-borne dispersion or aerosol comprising particles having an average diameter between about 0.1 and about 6.5 .mu.m.
Claims32
A method for forming fine particles having an average diameter less than about 6.5 .mu.m of a substance comprising:
- (a) substantially dissolving or suspending said substance in a first nongaseous fluid to form a first solution or suspension;
- (b) mixing said first solution or suspension with a second nongaseous fluid to form a composition comprising:
- (1) said substance;
- (2) an immiscible mixture of said first and second nongaseous fluids;
- wherein at least one of said nongaseous fluids is a supercritical fluid;
- and
- rapidly reducing the pressure on said composition whereby at least one of said nongaseous fluids becomes a gas, and whereby a gas-borne dispersion of said fine particles of said substance having an average diameter less than about 6.5 .mu.m is formed.
A method for forming fine particles of a substance comprising:
- (a) substantially dissolving or suspending said substance in a first, nongaseous, fluid to form a first solution or suspension;
- (b) mixing said first solution or suspension with a second, supercritical, fluid to form a composition comprising:
- (1) said substance;
- (2) an immiscible mixture of said first and second fluids;
- and
- (c) rapidly reducing the pressure on said composition whereby said second fluid becomes a gas, and whereby a gas-borne dispersion of said fine particles of said substance is formed.
Dependencies are inferred from the claim text.