Study On Preparation Of Photocatalytic Unidirectional Wet Textiles

With the advancement of social productivity and the improvement of human living standard, people are paying more and more attention on clothing’s comfort, function and even intelligence. Directional water transport fabric is a kind of functional textiles and it has high efficiency in liquid water transportation. In recent years researchers have done lots of work on the area of fabric’s directional water transportation. The achieving methods and application area of directional water transport fabric have been expanded.In this study, we have prepared directional water transport fabric through functional finishing, the photocatalytic water transport effect was studied. The comparison between effects of different finishing methods was made. The water transport mechanism of photo catalytic water transport was discussed.It is found that through the finishing and irradiation, the hydrophilicity of the fabric’s irradiated side is increased, so the wettability conversion is realized. When the irradiation is stopped this kind of conversion can be recovered. When the irradiation time is extended the time needed to recover is also extended.When the finished fabric is irradiated its unexposed side can also turn from hydrophobic to hydrophilic, but its speed of conversion is slower than the irradiated side. In a certain period the exposed side is more hydrophilic than the unexposed side. During the irradiation process the fabric’s accumulative one-way transport capacity (OWTC) is increasing with time.The sprayed fabric’s wettability conversion under irradiation was faster than the padded but its recovering speed was slower than the padded fabric. In the first 4 hours of irradiation the OWTC of the sprayed fabric was higher than the padded one but its maximal OWTC was lower than the padded fabric. The comparison of photocatalytic directional water transport effect between cotton fiber fabric and viscose fiber fabric was also made. It was found that the viscose fabric’s wettability conversion was faster than the cotton fabric. As for the OWTC, although in the first 4 hours the viscose fabric is faster than the padded, but on the whole, there wasn’t much difference.The sprayed fabric’s tensile strength and burst strength were higher than the padded, but its air permeability and resistance hydrostatic pressure is lower than the padded fabric.The influence on wearability of finishing was studied, the results show that:the fabric’s air permeability is not affected by the finishing, on the contrary its permeability has increased a bit which may be ascribed to the erosion of nitric acid; The tensile strength and burst strength of fabric declines largely after finishing,this is also due to the nitric acid’s erosion; The fabric’s resistance hydrostatic pressure has increased a lot after finishing which is owing to the increase of hydrophobicity.Fourier Transform Infrared Spectroscopy (FTIR) was employed to explore the mechanism of the wettability conversion. It was found that after irradiation photogenerated holes were formed on the TiO2 surface, the hydrolysis ion in the air was absorbed into the holes which lead to the forming of hydrophilic area, after irradiation the hydroxyl group was replaced by the Oxygen in the air, so the TiO2 returned to hydrophobic.