PDA/PEI-induced in-situ growth of a lotus leaf-like TiO2 nanoparticle film on N-halamine cotton fabric for photocatalytic, self-cleaning and efficient antibacterial performance

Functional cotton fabrics with N-halamine structure were prepared by in situ growth of titanium dioxide (TiO2) nanoparticles on PDA/PEI (polydopamine/polyethyleneimine) coating, which effectively solved the problem of bacterial growth and stain adhesion for cotton fabrics. The results of SEM, XRD, and XPS analyses showed that the TiO2 nanoparticles were successfully produced on the surface of the fabric and were spherical at 60 & DEG;C. Photoluminescence (PL) spectra showed that PDA and TiO2 were beneficial in improving the electron-hole pairs separation efficiency of the modified fabrics. And the weight percentage of TiO2 nanoparticles deposited on the fabric surface was 14.4% from TG analysis. Photocatalytic experiments showed that the TiO2-deposited cotton fabrics degraded 97.1% of methylene blue (MB) solution within 12 h and had excellent stability. After chlorination, the TiO2-deposited cotton fabrics could sterilize 100% Staphylococcus aureus and Escherichia coli within 30 min, and the TiO2 was able to reduce the chlorine loss of N-halamine upon UV irradiation. By comparing the water contact angles of the TiO2-deposited cotton fabrics at different temperatures, it was found that the TiO2-deposited cotton fabrics at 60 & DEG;C have a lotus leaf-like hydrophobic property which brings self-cleaning performance. After loading with TiO2 nanoparticles, the fabrics had desirable cytocompatibility and the breaking strength was also improved. Graphic abstract