Nano-cotton fabrics with UV protection

In the present work, we have attempted nano-finishing of bleached as well as reactive dyed cotton fabrics with TiO2 nanoparticles. First of all, the cotton fabrics were pre-treated with a linking agent in the presence of a catalyst. After drying at high temperature, the fabrics were cured. This linking agent with two free carboxylic acid groups is able to bind both the cotton and TiO2. The first carboxylic acid group forms a covalent ester bond with a hydroxyl group of cellulose, while the second one can anchor TiO2 by electrostatic interaction. These pretreated cotton fabrics were further coated with aqueous TiO2 suspension, after sonicating. Both the anatase and rutile phases of TiO2, as well as the 3:1 and 1:3 mixtures were used in the study. After drying, the unbound TiO2 was washed out under sonication. Further, the samples were washed in cold water and air dried. In order to characterize the samples after incorporation of the nanoparticles, Scanning Electron Microscopy (SEM) was used to observe both the morphology and composition of the samples (before and after 10 home launderings). Transmision Electron Microscopy (TEM) was used to study the size, form and distribution of the nanoparticles and Atomic Force Microscopy (AFM) to observe the surface texture of the samples. Energy Dispersive X-ray Microanalysis (EDX) was used for the surface analysis through the interactions between the matter and electromagnetic radiation. It was found that the TiO2 nanoparticles were intact on cotton surface even after the launderings, showing good adhesion of the nanoparticles to the fabric surface. Further, the UPF values of the coated samples were also measured before and after launderings. It was found that even after the launderings, a high UPF value of 50+ was measured for all the samples, but rutile phase was found to be better than anatase phase. In this way, an industrial process is being developed for producing cotton fabrics of high UV protectio