The majority of the currently produced film packaging are made of plastics, with PET being one of the most frequently used polymers. The greatest area of application of plastics in Europe is the packaging sector, with a nearly 40% share in the plastics industry in 2013, generating a positive trade balance amounting to EUR 18 billion. PET plastics are not sufficiently resistant to UV radiation, which causes their ageing and degradation.
The poor UV-resistance of plastics often leads to quicker spoilage of food and destruction of other everyday use products placed in transparent packaging covers. One of the examples is milk, where UV radiation leads to decomposition of vitamin A and oxidation of milk fat. UV radiation also adversely affects the packaging aesthetic qualities, i.e. discoloration and colour fading. Efficient methods of plastics surface modification are being sought, in combination with a material that would absorb UV-A light effectively, preserving the aesthetic qualities of the material at the same time, among others the colour or transparency scale.
| PEŁNA WERSJA ARTYKUŁU DO POBRANIA | ||
| Eng. Bartosz Woźniak |
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 Engineer at the Institute of High-Pressure Physics, Polish Academy of Sciences in Warsaw. His main research activities are study and development of surface modification of materials by ultrasonic coating with nanoparticles (ZnO, hydroxyapatite, etc.). In his current R&D projects he deals with nanocoatings formation mechanism on various substrates for medical use. |
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| STRESZCZENIE Pokrywanie materiałów syntetycznych cząstkami nano-tlenku cynku pełniącymi funkcję filtru UV |
| Tlenek cynku (ZnO) jest zaliczany do filtrów fizycznych skutecznie pochłaniających światło ultrafioletowe w zakresie UV-A. ZnO wytworzony w Laboratorium Nanostruktur charakteryzował się nanometryczną wielkością cząstek 28±4 nm (SSA BET). Pokrywając powierzchnię transparentnej folii z politereftalanu etylenu (PET) nanocząstkami ZnO autorzy mieli na celu uzyskanie warstwy pochłaniającej promieniowanie UV-A. Pokrywanie odbywało się w wodnej zawiesinie ZnO, w której wytworzono zjawisko kawitacji akustycznej, gdzie implozja pęcherzy kawitacyjnych prowadziła do osadzenia się nanocząstek ZnO na powierzchni foli PET. W ramach prac opracowano optymalne parametry procesu pokrywania folii PET uzyskując filtr w postaci warstwy ZnO, skutecznie pochłaniającej światło UV. |
| SUMMARY |
| Zinc oxide (ZnO) is one of physical filters that effectively absorb ultraviolet light in the UV-A range. ZnO produced at the Laboratory of Nanostructures was characterised by nanometric particle size of 28±4 nm (SSA BET). By coating the surface of a transparent film of polyethylene terephthalate (PET) with ZnO nanoparticles, the authors aimed at obtaining a coating that absorbs UV-A radiation. The coating process took place in a water suspension of ZnO, in which the phenomenon of acoustic cavitation was triggered, where the implosion of cavitation bubbles led to deposition of ZnO nanoparticles on the PET film surface. As part of the work, optimum parameters of the PET film coating process were developed, thus obtaining a filter in the form of a ZnO coating that effectively absorbs UV light. |
| Zapraszamy do składania zamówień na prenumeratę i numery archiwalne |
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