Investigation of antibacterial property of functionalized polypropylene nonwoven fabrics by S-N Co-doped nano-TiO₂ films

This study focused on the antibacterial and ultraviolet protection properties of the functionalized polypropylene nonwoven fabrics (PPNWF). Sulfur and nitrogen co-doped titanium dioxide (S-N-TiO2 ) sol was synthesized by sol-gel method and S-N-TiO2 films were coated on the surface of PPNWF with impregnating method. The tensile strength, mass per unit area, thickness, whiteness, and glossiness of the prepared simples were investigated. The ultraviolet protection properties of the samples were assessed by ultraviolet transmittance spectrum and Ultraviolet Protection Facto. The results show that ultraviolet protection properties, tensile strength, and mass per unit area of the functionalized fabrics increase whereas its whiteness and glossiness decrease. The structural analysis and chemical composition of S-N-TiO2 were made by X-ray diffraction and X-ray photoelectron spectroscopy, which indicate the successful doping of S and N into TiO2 . The results of Fourier transform infrared spectrometer and scanning electron microscopy show that S-N-TiO2 nano-films have been well dispersed on the surface of the PPNWF, which is beneficial to the ultraviolet protection property and antibacterial activity of the samples. The antibacterial activities were evaluated by shake flask method. It is found that the S-N-TiO2 nano-films coated PPNWF (S-N-TiO2 /PPNWF) exhibit excellent antibacterial activities against both Staphylococcus aureus and Escherichia coli, and the antibacterial rate of 96.8% and 98.4% against Staphylococcus aureus and Escherichia coli, respectively. After 50 cycles of consecutive laundering, the antibacterial rates remain over 85.48% and 84.4% for Staphylococcus aureus and Escherichia coli, respectively. It indicates that the antibacterial performance of the S-N-TiO2 /PPNWF fabrics is also durable.