Stuttgart,Germany:A recent study by the Fraunhofer Institute for Interfacial Engineering and Biotechnology(IGB)in Stuttgart has demonstrated a new way of cleaning outdoor furniture:Using sunlight.
Garden furniture that has been left in the shade too long becomes covered with a film of algae,moss,bacteria and fungi,which can be difficult to remove.Scientists are now hoping that they can solve this problem by incorporating titanium dioxide molecules in the plastic used to make the garden chair.
When these titanium dioxide molecules are activated by the ultraviolet light in the sun's rays,they trigger an electrochemical reaction which produces free radicals.These and other active molecules destroy bacteria,fungi and similar organisms,first destroying the cell walls and then penetrating the cytoplasm–the substance that fills the cell.This effectively damages the bacteria's DNA.
Explaining the mechanism of the test,group manager at the IGB,Dr Iris Trick,said:"We ran some outdoor tests on garden chair armrests with photocatalytic coatings(containing the titanium dioxide molecules)and compared them to ones made from conventional plastic."
Dr Trick and her team then sprayed the coated and uncoated armrests with a mixture of various bacteria,mosses,algae and fungi and then left them exposed to weather conditions for two years.At the end of the test,it was almost impossible to remove the layer of dirt from the normal armrests,yet the armrests made from photocatalytic plastics were still almost completely clean and white.
Currently,researchers at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart are working on paints for building facades which contain titanium dioxide particles.If the wall gets dirty,the photocatalysis degrades the organic contaminants and the paint stays reasonably clean.
