Hydrophilic Surface Treatment of Carbon Powder Using CO2 Plasma Activated Gas

Carbon powders exhibit electrical conductivity that causes the powders to agglomerate due to the applied electrostatic forces and discharges capacitance when used for surface treatments with plasma sources. To avoid this obstacle, a non-direct method is used with active gas that is generated through plasma. This active gas is in contact with the carbon powder so that the hydrophilic characteristics are formed. It is the carboxyl COO− functional group that causes hydrophilic improvement and it is shown to increase in the carbon surface after soft oxidation. The wettability of carbon powder gradually improves with more plasma treatment time. This is shown through a simple water dispersion test. Eventually, the dispersed aqueous solution gradually separates the powder, which either floats or sinks. The sample treated for 60 min is shown to continuously sustain dispersibility in water over a long period of time.