Non-equilibrium plasmas offer a unique reactive environment for the synthesis of chemicals and materials. Electrons are heated, typically by coupling electrical energy, to temperatures far above room temperature, while the background gas atoms or molecules remain close to room temperature.  The electrons, or the other excited species they create including radicals, can then drive reactions in the gas phase, or at a solid or liquid boundary.  If directed and controlled, chemicals or materials are thus synthesized using only electricity at relatively low temperatures.

Plasmas have been historically formed at vacuum pressures in order to have the long mean free paths needed for sufficient heating of electrons. Our group has developed plasmas that stably operate at atmospheric pressure while maintaining non-equilibrium properties. These plasmas can easily be interfaced with solids or liquids that are not compatible with vacuum such as polymers and water.

We are in general interested in how non-equilibrium plasma systems can address challenges in chemicals and materials synthesis. For example, plasmas are capable of synthesizing chemicals and materials at lower temperatures and lower pressures than thermally-activated processes.  Chemical bonds that are extremely stable such as nitrogen can be easily activated in a plasma. Reactions may be carried out away from thermodynamic equilibrium leading to metastable products.

Three non-equilibrium plasma systems of current interest are 1) gas-phase, continuous, substrate-free, 2) plasma-liquid, and 3) plasma-film.