title: EPR investigation of UV light effect on calcium carbonate powders with different grain sizes.
abstract: This study is based on investigation of calcium carbonate powders with different grain sizes exposed to UV light. Calcium carbonate is widely used in many branches of industry, e.g. as a filler for polymer materials; therefore, knowing its properties, among them also its reaction to UV light, is essential. Samples of powdered calcium carbonate with average grain sizes of 69 and 300 nm and 2.1, 6, 16, 25 µm were used in this investigation. Measurements were performed at room temperature using EPR X-band spectrometer, and they have shown the additional signals induced by the light from Hg lamp. The effect of annealing of the micro-grain samples was also studied. The spectra of four micro-grain samples after irradiation are similar, but there are differences between them and the other two powders, which could be related to the different sizes of their grains. Further studies based on these preliminary results may prove useful in research of photodegradation of CaCO3-filled materials, as well as helpful in increasing the accuracy of dating of archaeological and geological objects.
authors.affiliation: Medical Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań 61-614, Poland zuziakab@amu.edu.pl.
authors.forename: Zuzanna
authors.initials: Z
authors.lastname: Kabacińska
authors.affiliation: Medical Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań 61-614, Poland.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Krzyminiewski
authors.affiliation: Medical Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań 61-614, Poland.
authors.forename: Bernadeta
authors.initials: B
authors.lastname: Dobosz
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry* / Q000528:radiation effects*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006801:Humans; D011208:Powders / Q000737:chemistry* / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D011208:Powders; D002119:Calcium Carbonate