MDA Update Article: Flaming the Mist: CCVD Nanopowder Production

October 3, 2002 – Flaming the Mist: CCVD Nanopowder Production
Igniting an aerosol spray is something you should never try to do-unless you intend to produce and collect nanopowders.

It’s called combustion chemical vapor deposition (CCVD), a technique originally invented to deposit thin films on substrates. MicroCoating Technologies, Inc. (MCT, Atlanta, GA), uses the same basic technology to create a variety of metal and ceramic nanopowders for applications including catalysts, chemical-mechanical polishing, and pigments.

In 1999, BMDO funded MCT with an SBIR Phase I contract to prove that CCVD could be used successfully to make nanopowders with desired size and morphology. Subsequently, BMDO awarded a Phase II follow-on contract to MCT to optimize the pro-cess, to develop an efficient collection system, and to scale up an affordable method of production. Early collection efforts yielded up to 20 percent nanopowders with desired properties and MCT claims its yield now approaches 80 percent in research quantities. It hopes to have a process in place within six months to produce kilograms per hour.

The key to MCT’s success is a patented nebulizer called the Nanomiser(r) device. A precursor solution consisting of materials dissolved in organic solvents is pumped to the Nanomiser device which atomizes the solution into submicron-size droplets. The droplets are carried by convection to a flame where they are vaporized and combusted. The resulting vapor cools and forms particles. By adjusting process parameters, chemists can vary the quality and quantity of nanopowders produced. For example, cerium oxide nanopowder intended for chemical polishing and electrolyte applications can be made in particle size ranges between 6 and 30 nm.

This approach has potential advantages including ease of synthesis of complex oxides, high purity, good particle size control, high yield and low-cost production. MCT capitalizes on these benefits by targeting applications such as catalysts, chemical mechanical polishing, and solid oxide fuel cells.

MCT intends to pursue one of three strategies as the nanopowder market matures. The first would be to license its technology for a specific field of use and sell the Nanomiser device to the customer. The second is to manufacture and sell nano-powders. The third would be to find a potential partner for a joint-venture arrangement. The company invites inquiries from interested parties who would like to know more about the Nanomiser device and its products, or about possibilities for licensing or partnership.

-A. Gruen