Green mechanochemical activation of five natural Ti–Fe minerals for hygienic coatings with antibacterial and hydrophilic properties

This study demonstrates a green, additive-free and scalable route for producing hygienic surface coating powders from five natural Ti–Fe minerals. High-energy mechanochemical activation converted rutile, leucoxene, ilmenite, hydro-ilmenite and magnetic leucoxene into nanocrystalline particles with increased surface reactivity, achieved without dopants, surfactants or chemical precursors. The milling process introduced structural changes, including crystal defects, lattice distortion and a modified near-surface Ti/Fe balance, which collectively supported composition-dependent antibacterial and hydrophilic behaviour. Ti-rich compositions showed greater effectiveness against E. coli , while Fe-richer minerals were more active toward S. aureus , with magnetic leucoxene exhibiting a balanced response across both strains. The strong reduction in contact angle further enabled water spreading, indicating self-cleaning potential. Overall, the results establish a clear structure–function relationship in which mechanochemical activation of natural Ti–Fe minerals determines both wetting and antibacterial responses, enabling the rational selection of natural Ti–Fe minerals for hygienic coating applications in construction and public-contact surfaces.