Method for the production of multiphase composite materials using microwave plasma process

摘要

Disclosed herein is a method to produce multiphase composite materials directly from solution precursor droplets by a fast pyrolysis process using a microwave plasma embodiment containing a microwave generating source, a dielectric plasma torch, and a droplet maker. Here, using homogenous solution precursors, droplets are generated with a narrow size distribution, and are injected and introduced into the microwave plasma torch with generally uniform thermal path. The generally uniform thermal path in the torch is achieved by axial injection of droplets into an axisymmetric hot zone with laminar flows. Upon exposing to high temperature within the plasma with controlled residence time, the droplets are pyrolyzed and converted into particles by quenching with a controlled rate of the exhaust gas in a gas chamber. The particles generated have generally uniform sizes and uniform thermal history, and can be used for a variety of applications.

主权项

1. A method of making particles using a microwave generated plasma comprising:
a. preparing a salt solution in water, in organic solvent, or in a mixture of water and organic solvent; b. generating precursor droplets from said salt solution using a feed injection device; c. introducing axially said precursor droplets into a microwave plasma torch; d. entraining said precursor droplets using at least two concentric laminar gas flows towards a microwave generated plasma; e. exposing said precursor droplets to high temperature within said microwave generated plasma; f. controlling residence time of said precursor droplets in said microwave generated plasma; g. controlling quenching rates of an exhaust gas of said microwave generated plasma in a gas chamber; h. filtering the exhaust gas of said microwave generated plasma; and i. extracting particles from said exhaust gas.