Influence of nano-silica on radon gas diffusion through cement mixture: Correlation with wettability

Cement mixtures containing different percentage (0 %-1.5 %) of amorphous nano-silica extracted from wild oat straw were prepared. The effect of the percentage of the added silica on the diffusion of radon gas through the mixture was studied. The results were correlated with the change in wettability of the mixture using contact angle measurements. It was found that the addition of silica improves the resistance of the cement mixture to radon gas diffusion. This was accompanied by a decrease in surface wettability. It was found that the mixture containing 0.75 % amorphous silica has the best resistance to radon gas penetration and the largest contact angle among the studied mixtures. The mixture's resistance to radon gas penetration at this percentage improved by more than 17 %. The results in this report indicate that nanosilica extracted from agricultural sources is promising for nuclear radiation protection applications.