Nano-bio finishing of cotton fabric with quaternized chitosan Schiff base-TiO2-ZnO nanocomposites for antimicrobial and UV protection applications

The purpose of this work is to offer a novel approach to designing multifunctional technical cotton textiles by coating them with smart bio-materials. Two different ternary nanocomposites (NC1, NC2) comprising (ammonium-salicylidene) chitosan Schiff base (ASCSB), TiO2, and ZnO nanoparticles were in-situ prepared and applied for treating cotton fibers using the facile pad-dry-cure process to impart antimicrobial and ultraviolet protection characteristics. Notably, NC1 is TiO2-rich, while NC2 is rich in ZnO. The physicochemical and visual characteristics of the new nanocomposites and the treated fabrics were investigated by spectral, microscopic, and thermal methods. The as-prepared NC1 exhibited a more homogeneous distribution, higher depositing density and smaller mean nanoparticle size (48 nm) when compared to NC2 (56 nm). In contrast, NC2-treated fabrics showed a higher depositing density of nanoparticles than NC1-treated ones. The treated cotton fibers demonstrated strong and sustainable antimicrobial impacts on S. aureus, E. coli, and C. albicans pathogens, with more effective performance for NC2-treated textiles in comparison to NC1-treated fabrics. The NC2-remediated cotton fabrics demonstrated a higher UV protection factor (UPF) value (53) as compared to NC1-coated fabrics (35), indicating that the ZnO-rich nanocomposite endowed cotton fabrics with more ultraviolet protection than TiO2-rich nanocomposite.