Surface modification of metal substrates using dielectric barrier discharge plasma and the wettability study

Forming endurable coatings on the surface of metals in a simple, green, efficient manner is still challenging. Plasma surface modification offers an effective method to alter metal surfaces’ physicochemical properties and endow them with new functionalities. A DBD plasma method is presented for the surface modification of metals using perfluorooctyltriethoxysilane (POTS) and polyethylene glycol (PEG 200) as the precursors. Systematic experiments were carried out against galvanized iron to investigate the process feasibility. This method was further expanded to diverse metal substrates to examine the process versatility and practical applications. The surface of the galvanized iron substrates were successfully modified by the POTS and PEG 200 precursors to form hydrophobic coatings and hydrophilic coatings, respectively. The composition, morphology, surface roughness, and wettability of the metal substrates could be adjusted by the plasma treatment time. The plasma technique exhibits have high efficiency and good versatility in tuning the wettability of different metal substrates. Furthermore, the plasma-modified substrates also displayed improved corrosion resistance via the salt spray test. This work enriches the study of DBD plasma surface modification as an effective method to functionalize metals with desirable properties.