Functionalization of cotton fabrics with corona/air RF plasma and colloidal TiO2 nanoparticles

This study discusses the possibility of using a corona discharge at atmospheric pressure and air RF plasma at low pressure for the cotton fibre activation prior to deposition of colloidal TiO2 nanoparticles in order to enhance antibacterial, UV protective and self-cleaning properties. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of TiO2 nanoparticles on the surface of cotton fibres. XPS elemental mapping indicated that TiO2 nanoparticles were more evenly distributed across the surface of untreated and corona pre-treated cotton fabrics in comparison with RF plasma pre-treated fabric. Atomic absorption spectroscopy measurements revealed that the equivalent total content of TiO2 in the cotton fabrics pre-treated by corona and RF plasma was 31% higher than in the fabric that did not undergo any treatment prior to loading of TiO2 nanoparticles. In order to achieve maximum bacteria (Gram-negative bacteria Escherichia coli) reduction, untreated cotton fabric had to be loaded with colloidal TiO2 nanoparticles twice, but only once following corona or RF plasma pre-treatment. Deposition of TiO2 nanoparticles onto cotton fabrics provided maximum UV protective rating of 50+. Extraordinary photocatalytic activity of TiO2 nanoparticles deposited onto cotton fabrics was proved by self-cleaning of blueberry juice stains and photodegradation of methylene blue in aqueous solution under UV illumination.