Estudo das propriedades self-cleaning em substrato têxtil e magnéticas do ZnO: Ag nanoestruturado

Abstract

ZnO:Ag/Ag nanostructures were synthesized at 100 °C by microwave energy in order to obtain a material with photocatalytic properties on low energy levels and magnetics. The applications of nanomagnetism are diverse ranging from geology, magnetic recording, to medicine. Thus, the material was obtained from the precursors: zinc acetate dihydrate and silver nitrate (as dopant) in different concentrations such as ZnO1-x:Agx (x= 0, 0.01 e 0.02). Adding polyvinylpyrrolidone synthesis (as surfactant) and hexamethylene as a reducing agent/precipitating agent. For its characterization, the following techniques were performed to evaluate, Diffraction of X-Rays (XRD), Scanning Electron Microscopy and Field Effect (SEM/FEG), Transmission Electron Microscopy (TEM), analysis by isotherms Brunauer surface area Emmett and Taller (BET), Photoluminescence (PL) and Spectrophotometry. The XRD results indicated mainly crystalline phases of wurtzite ZnO for the and for face-centered cubic metallic silver nanoparticles. By undertaking spectrophotometric absorbance it was confirmed by the orange color wavelength methyl photocatalysis ZnO doped with 1 mol% silver synthesized in 10 minutes in an average time of 2 hours and 30 min. Transmittance was obtained with direct and indirect gap of the compositions. All powders obtained showed the photoluminescence property generated by structural defects. The doping of the pure material caused a shift from green to between yellow and red, thus confirming changes in the electrical properties of the same due to decrease in the gap and also showed peak regarding the metal nanoparticles silver around 390 nm. The magnetic properties of the samples were performed using the physical property measurement system (PPMS) from Quantum. Under these conditions the doping improved the photocatalytic property of ZnO. With these prior results, to prove this application the impregnation step was carried out with particles of polyamide by immersion deposition method (dip coating), for this a styrene and butyl acrylate was utilised. The characterization of nano coating ware used using the following techniques: XRD, SEM/EDS, thermal analysis (TG/DTA), Infrared Spectroscopy Fourier Transform (FTIR), atomic force microscopy (AFM) and contact angle. For evaluation of the self-cleaning for photocatalysis property was based on the color change (ΔE) using the spectrophotometer by reflectance before and after subjecting the samples to ultraviolet radiation for anthocyanins.