Highly reactive plasma for advanced composites processing

We will study characteristics of reactive, thermodynamically distinctly non-equilibrium plasmas that are generated in two-atom molecular gases. Possibilities for reaching a high density of neutral atoms in plasmas characterized by a low neutral gas and ion gas temperature will be studied. The latter temperatures will be remained below 100C while the ionization degree will be kept below 0.0001%. The goal is to reach a dissociation degree about 50% in plasmas with such characteristics. A large plasma reactor with a useful volume of the order of m3 will be constructed. Plasma parameters in the reactor will be measured with specially adopted electrical and catalytic probes, emission optical spectroscopy, cavity ring down absorption spectroscopy and mass spectrometry. Experiments on plasma treatment of advanced graphite-polymer composites will be performed in plasma reactor. The composites have been recently introduced in industrial production as suitable substitutes for metals. Plasma treatment will replace classical treatment of said composites that currently employ application of environmentally unsuitable methods for composite treatment before metallization. Namely, currently used technologies include wet chemical etching with lye, wet chemical cleaning, surface activation with palladium from a cyanide bath, and electrodeless metallization with a metal from a chemical solution. All mentioned technologies are harmful to the environment and the goal is to replace them with ecological benign dry technologies that include selective plasma etching and surface activation with highly reactive plasma. Physical and chemical processes on composite surfaces will be monitored with methods for surface, interface and thin film characterization including the Auger and X-ray photoelectron spectroscopy, scanning electron microscopy, electron microprobe as well as methods for measurement surface energy, adhesion, roughness and electrical resistance.