Modification of carbon fibre reinforced polymer (CFRP) surface with sodium dodecyl sulphate for mitigation of cathodic activity

Suppression of electrochemical activity (cathodic activity) on CFRP surface at cathodic potentials consistent with galvanic coupling of CFRP with active metals like aluminium and zinc have been demonstrated by electrochemical treatment of CFRP surface in the presence of sodium dodecyl sulphate (SDS). Modification to the CFRP surface by SDS adsorption was established using electrochemical impedance spectroscopy, cyclic voltammetry, and confocal Raman spectroscopy and atomic force microscopy. Electrochemical test results indicate interaction of SDS with CFRP with persistent effects, manifesting in a sustained suppression of electrochemical activity even after washing the treated CFRP surface. Mitigation of CFRP degradation under cathodic polarization in the presence of SDS and/or after prior exposure to SDS was established from scanning electron microscopy. Based on results obtained herein, plausible mechanisms/configurations involved in SDS interaction(s) with carbon fibre surfaces of the CFRP composite (that most probably account for reduced cathodic activity) were postulated.