engleski

Nanomaterial Additives in Clay-Based Composites for the Non-ionizing Radiation Absorption

While the detrimental effects of ionizing electromagnetic (EM) radiation on human health are well established and thoroughly investigated, the effects of the non-ionizing EM radiation have been debated and studied only recently. In this study, clay composites were subjected to EM transmission testing in the region of non-ionizing radiation between 1.5 and 6.0 GHz which is where the frequency of the most mobile telephony systems can be found. Specimens were made with partial substitution of clay (2.5 and 5 wt.%) with different nanomaterials: fly ash, Titanium dioxides (TiO2 -anatase and rutile), Zinc Ferrite (ZnFe2O4), Maghemite (γ-Fe2O3), Antimony Tin Oxide (ATO), and Multiwalled Carbon Nanotubes (MWCNT). All nanomaterials were characterized by B.E.T. nitrogen adsorption method to determine the specific surface area, and Thermogravimetric methods (TGA/DSC) to designate their thermal properties. Phase analysis was performed by Powder X-ray diffraction (PXRD), and the morphology studied by Electron Microscopy (SEM-EDX). The oxide content was measured by X-ray Fluorescence (ED-XRF) and the quantity of heavy metal determined by Plasma Excitation Spectrometry (ICP- OES). EM radiation transmission was evaluated using Anritsu ms2038 - Spectrum Analyzer. The lowest transmission was reported for the clay specimens with ATO and TiO2 at a frequency of 4 GHz and it is -17 dB. In conclusion, the addition of the certain nanoparticles into clay can significantly lower the penetration of non- ionizing EM radiation through construction elements made from such composite materials.

Non-ionizing radiation, clay, electromagnetic radiation, shielding, nanomaterials, EM transmission

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