Modification of glass surfaces adhesion properties by atmospheric pressure plasma torch

This work is focused in the surface modification of glass samples by an atmospheric pressure plasma torch (APPT), with the aim of properly characterizing every chemical surface modification which could contribute to the assessment of reliable adhesive bonding with polyurethane, silicone, epoxy and cyanoacrylate adhesives.Characterization of glass surfaces both pristine and plasma treated is achieved by surface energy determination through contact angle measurements, Fourier transform infrared spectroscopy in attenuated total multiple reflection mode (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and surface roughness determination. Moreover, the hydrophobic recovery processes suffered by the samples throughout a period of 30 days of storage after APPT treatment is evaluated. Finally, adherence tests are carried out following the ASTM D4541 standard. Results show an increased surface energy with treatment, which partially recovered its initial value with aging. For the adhesive bonding, only the polyurethane shows an improvement on resistance among all the tested adhesive fluids. It is possible to conclude a cleaning, etching and activation effects on the glass surfaces after plasma treatment, with a change in the locus of failure from adhesive to cohesive in some cases, and a reduction in data standard deviation.