N. Radić

Deposition of Gold Nanoparticles on Polypropylene Nonwoven Pretreated by Dielectric Barrier Discharge and Diffuse Coplanar Surface Barrier Discharge

The aim of this study was to examine and compare the potentials of two different ambient air plasma treatments: volume dielectric barrier discharge and diffuse coplanar surface barrier discharge, for the activation of polypropylene (PP) nonwovens surface. This was done in order to enhance the deposition of gold nanoparticles (AuNPs) onto PP surface. AuNPs were attached onto PP surface from colloidal solution prepared without stabilizers. Scanning electron microscopy, atomic force microscopy, attenuated total reflection-Fourier transform infrared spectroscopy, water absorption, and AuNPs uptake were used to assess the surface changes due to the plasma treatment, and to evaluate the durability of the achieved treatment effects. Finally, as a very important aspiration of the research, antibacterial activity of AuNPs loaded PP nonwovens against pathogens Staphylococcus aureus and Escherichia coli was evaluated in vitro. The plasma modified PP nonwovens have highly improved wetting and sorption properties. The PP nonwovens loaded with 17–62xa0mg/kg AuNPs exhibit antibacterial activity against tested pathogens. Surprisingly, this activity was enhanced by the first sample rinsing.

Influence of iron doping on photocatalytic activity of TiO2 coatings formed on titanium by plasma electrolytic oxidation

This paper presents the results of our recent investigation focused on the preparation and possible photocatalytic application of iron doped TiO2 coatings formed by plasma electrolytic oxidation of high purity titanium in electrolyte containing FeSO4. The morphology, phase and elemental composition, and absorption band of the coatings were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. The photocatalytic activity of coatings was evaluated by measuring the degradation of methyl orange under simulated sunlight conditions. It was found that the addition of iron precursor to electrolyte solution improves the photocatalytic properties of obtained coatings with respect to pure TiO2 coating. The incorporation of iron in TiO2 lattice was identified as the main factor affecting the increase of photocatalytic activity. The highest photocatalytic activity was observed when coatings were processed for 2xa0min with addition of 1xa0g/L FeSO4 to electrolyte.