Impact of ZnO and TiO₂ on C-S-H composition and its correlation with antifungal properties in cement pastes

This study presents a self-cleaning cement incorporating zinc oxide and titanium dioxide nanoparticles, used alone or in combination. The objective is to develop high-performance materials suitable for different environments, inhibiting fungal growth while providing self-cleaning properties. In parallel, the impact of these nanoparticles on the mineralogy and structure of C-S-H was examined. Used as partial cement substitutes (0–3% by weight), the pastes were characterized after 28 days of hydration by XRD, XRF, DSC and TG to evaluate reactivity and Ca/Si ratios of the formed C-S-H. Next, a new alternative method for the indirect determination of the Ca/Si ratio of the C-S-H gel in cements is also proposed using three methods. The antimicrobial surfaces were assessed for antifungal activity against Penicillium brevicompactum, Trichoderma reesei and Aspergillus niger on Czapek-Dox agar. Results show that the addition of TiO₂ and ZnO yields fungal-resistant surfaces, promoting hygiene, sustainability and innovation in construction.