PDA/PEI-induced in-situ growth of a lotus leaf-like TiO 2 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 (TiO 2 ) 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 TiO 2 nanoparticles were successfully produced on the surface of the fabric and were spherical at 60 °C. Photoluminescence (PL) spectra showed that PDA and TiO 2 were beneficial in improving the electron–hole pairs separation efficiency of the modified fabrics. And the weight percentage of TiO 2 nanoparticles deposited on the fabric surface was 14.4% from TG analysis. Photocatalytic experiments showed that the TiO 2 -deposited cotton fabrics degraded 97.1% of methylene blue (MB) solution within 12 h and had excellent stability. After chlorination, the TiO 2 -deposited cotton fabrics could sterilize 100% Staphylococcus aureus and Escherichia coli within 30 min, and the TiO 2 was able to reduce the chlorine loss of N-halamine upon UV irradiation. By comparing the water contact angles of the TiO 2 -deposited cotton fabrics at different temperatures, it was found that the TiO 2 -deposited cotton fabrics at 60 °C have a lotus leaf-like hydrophobic property which brings self-cleaning performance. After loading with TiO 2 nanoparticles, the fabrics had desirable cytocompatibility and the breaking strength was also improved. Graphic abstract