Fluorination of carbon fibres in atmospheric plasma

Carbon fibres were successfully fluorinated in atmospheric-pressure plasma. By treating carbon fibres in a chlorodifluoromethane containing nitrogen atmospheric-pressure plasma, we were able to introduce fluorine groups to the surface of the carbon fibres. XPS confirms the presence of fluorine moieties on the carbon fibre surfaces. Measured contact angles confirm a significantly increased hydrophobicity of the treated carbon fibres. Zeta-potential measurements showed that acidic character of carbon fibres was increased. Although exposure of the carbon fibres to the atmospheric plasma jet causes surface sputtering; XRD analysis, Raman spectroscopy and conductivity measurements performed on the treated fibres show that atmospheric plasma treatment only modifies the surface of the carbon fibres without affecting the bulk properties.