Carbides are a class of high performance materials used in a variety of applications ranging from cutting tools to rocket nozzles. Examples of common carbides include Tungsten, Titanium and Boron Carbides. The synthesis of carbide is based on the reaction between carbon and metal or metal oxide powders at high temperatures. Current technology heavily relies on the use of carbon powders from the petrochemical industry. The reactant powders, or the already reacted carbide powder, are then pressed into specific shapes. Here, I will briefly detail current research on the use of renewable resources as the carbon source and on novel technologies to shape precursors to carbide parts.

The premise regarding the use of renewable resources is that a biopolymer-metal oxide nanoparticle composite can act as a carbide precursor. The biopolymer carbonizes below 1000 C leading to a carbon matrix decorated with metal nanoparticles. As the temperature is increased, these react to yield carbide. In my group we are exploring common biopolymers such as carrageenan, an extract from seaweed; chitin, from shrimp shells; konjac gum from the plant with the same name. We also actively exploring cellulose, from plants and bacteria, in the shape of powder, paper or individual fibers. The environmental cost of extracting these biopolymers is expected to be far less than petroleum-based ones while the colloidal proximity between the polymer and the metal nanopowders is expected to allow for the use of lower temperatures to complete the carbide-forming reaction. Thus, the process can be more energetically efficient than current ones.

Regarding manufacturing of precursor shapes, we are actively studying 1) the extrusion of composite pastes towards additive manufacturing of carbide precursors; 2) an origami-inspired technology by using cellulosic paper as the carbon source; and 3) a nanomanufacturing platform featuring the physical manipulation of bacterial cells capable of extruding cellulose nanofibers under optimized culture conditions.