TiO₂ Photocatalytic Antimicrobial Textile Coating

Anatase TiO₂ nanoparticles (P25 Evonik, 21 nm, BET 50 m²/g) applied to cotton or polyester at 1–4 g/m² via pad-dry-cure with silane binder (TEOS 0.5–1.5%) generate hydroxyl radicals (•OH, E° +2.8 V) upon UV irradiation (>3.2 eV), achieving complete bacterial inactivation (>6 log, E. coli K-12) within 60–120 min (JIS L 1902 adapted). ROS oxidize bacterial cell wall lipopolysaccharides, proteins, and DNA causing irreversible lysis. Efficacy is self-regenerating upon each UV exposure cycle. Dark-period antimicrobial activity is negligible, limiting use to light-exposed applications. Wash durability of 30–50 cycles with optimized silica-silane anchoring system. Hospital curtains with TiO₂ coating reduce surface bacterial contamination by 85–90% versus uncoated controls in clinical trials.