Surface modification of activated carbon using an atmospheric pressure dielectric barrier discharge (DBD) plasma jet

Abstract

We successfully modified an activated carbon layer using an atmospheric pressure plasma jet. The plasma was generated in dielectric barrier discharge (DBD) configuration using Cu wire and Cu tape separated by dielectric glass with an inner diameter of ∼1 mm. An alternating current of 1.5 kV was supplied to the electrodes to generate the plasma using a mixture of Ar gas and ammonia vapor at varied flow speeds of 1 to 7 L/min for one-minute treatment. The changes to the wettability of the carbon surface were estimated from the contact angle of a water drop. After plasma treatment, a significant improvement in the surface hydrophilicity was observed. The contact angle decreased to ∼6° from its initial contact angle of 74°. This hydrophilic property was likely due to the successful attachment of an amino group supplied by the NH3 plasma. An amino-functional group was covalently bound to the carbon, which happened after etching by Ar plasma during the plasma jet processing. In addition, Fourier transform infrared (FTIR) profiles were taken to provide definitive proof of the suggested amino surface modification. Overall, the plasma treatment described in the present study may become a tool in surface treatment modification applications conducted in atmospheric conditions for carbon-based materials.