Search results for "Photodegradation"
showing 3 items of 153 documents
The weathering test of polypropylene composites
2000
Polipropylen "Malen P" czysty (a), kompozyty na jego podstawie napełniane (20% mas.) kredą lub talkiem (b) oraz produkty te stabilizowane dodatkowo stabilizatorem UV typu HALS ("Tinuvin 791") (c) poddano badaniom laboratoryjnego starzenia atmosferycznego. Badane próbki poddawano działaniu promieniowania ultrafioletowego w dawkach do 950 MJ/m2, w zaprogramowanych warunkach temperatury, wilgotności oraz nadeszczania. Postęp fotodegradacji polimeru śledzono na podstawie zmian ciężaru cząsteczkowego, jego rozkładu (GPC) oraz wybranych właściwości mechanicznych (wydłużenia względnego, naprężenia zrywającego, udarności z karbem). Określono również odporność próbek badanych białych kompozytów na z…
Structure and Photocatalytic Properties of TiO2-WO3Composites Prepared by Electrophoretic Deposition
2015
In this work TiO2-WO3 composite films containing different oxide concentrations were prepared by electrophoretic deposition on steel substrates. Composite coating structures were analyzed by X -ray diffraction, Raman spectra and scanning electron microscopy. The results showed an even distribution of WO3 particles in the entire composite layer. Light absorption measurements were used for photocatalytic properties evaluation. It was found that the removal ratio of methylene blue depends on the (TiO2):(WO3) concentration ratio. The most effective photodegradation was determined for the sample that was electrophoretically deposited from the suspension with the molar content ratio n(TiO2):n(WO3…
Photolytic and TiO2-Assisted Photodegradation of Aqueous Solutions of Tetracycline
2004
Aqueous solutions of tetracycline were UV-irradiated in homogeneous and heterogeneous systems. Tetracycline disappeared in both systems, but the presence of TiO2 accelerated the photodegradation of the antibiotic in comparison with direct photolysis. The rate of decomposition was dependent on the concentration of tetracycline and its degradation on the surface of TiO2 can be described by means of a pseudo-first order kinetics. Photolysis involved only the photodeamination of tetracycline and a partial mineralization. Unlikely, the treatment with TiO2 and UV-light resulted in a complete mineralization of the antibiotic drug.