Production of high surface area oxygen sensitive powders by Na flame synthesis

Cabot Corporation is developing a new particle generation platform that is ideally suited for the production of oxygen sensitive nano-scale powders. The Na Flame Synthesis process is based on the hypergolic vapor phase reaction between the metal-halide(s) of the desired element(s) and sodium in an inert atmosphere, such as argon. Provided that the sodium/metal halide ratio is maintained at or above the stoichiometric value, and the temperature is maintained sufficiently low, the conversion of halide is nearly 100%. The process produces high purity nano-scale particles, encapsulated in the sodium halide salt byproduct. The salt encapsulation aids in the collection and handling of particles that would otherwise be highly oxygen reactive, and the salt can be removed in subsequent process steps. The process is capable of producing particles composed of pure metals, metal alloys, intermetallics, metal-matrix composites, and non-oxide ceramics. Cabot's initial focus for this new platform is the production of high surface area tantalum powders for high-performance capacitors needed by the electronics industry, but many other applications are envisioned. These include materials that enable more efficient energy generation and storage, and materials with improved physical, thermal, and mechanical properties for advanced structural, aerospace, thermal management, and wear applications.