Hernando S. Salapare

Gas discharge plasma treatment of poly(ethylene glycol-co-1,3/1,4 cyclohexanedimethanol terephthalate) for enhanced paint adhesion

Low-energy hydrogen-ions and tetrafluoromethane-ions produced from a gas discharge ion source were irradiated to poly(ethylene glycol-co-1,3/1,4 cyclohexanedimethanol terephthalate) (PETG) sheets for enhancing paint adhesion. The ion beams were characterized using a cast steel mass spectrometer, while the untreated and treated samples were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, contact angle measurements, and profilometry. The paint adhesion was determined by using the standard method for evaluating adhesion by knife [ASTM D6677-07, Standard Test Method for Evaluating Adhesion by Knife (ASTM International, West Conshohocken, PA, 2012)] and was correlated with the calculation of the work of adhesion derived from the Young–Dupre equation. After plasma treatment, a significant decrease in the contact angle was observed in all samples, except for the CF4 ion-treated samples with the discharge current of 3 mA and an irradiation time of 30 min. At longer irrad...

Photodegradation of Rhodamine 6G by Amorphous TiO 2 Films Grown on Polymethylmethacrylate by Magnetron Sputtering

Titanium dioxide (TiO2) was deposited on polymethylmethacrylate (PMMA) substrates by magnetron sputtering using a Compact Planar Magnetron sputtering device at different flow rate ratios of O2/Ar. The deposited TiO2 on PMMA substrates were characterized using X-ray Diffraction analysis, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, UV-Visible Spectroscopy, and Scanning Electron Microscopy (SEM). These techniques confirm the deposition of a chemically stable amorphous TiO2 layer on the PMMA surface. Photocatalytic activity of the amorphous TiO2 layers were tested via photodegradation of Rhodamine 6G (Rh6G) dye solution. The samples were able to degrade 18–27% of the Rh6G solution after the initial 25 minutes of UV irradiation and complete degradation of Rh6G was observed after 7 hours of UV irradiation.