Preparation And Properties Of Superhydrophobic Photocatalytic Cotton Fabric By TiO₂-BC/PDMS

In recent years,with the continuous development of functional textiles,diversified demands have been presented.The research on superhydrophobic photocatalytic cotton fabrics has become a hot issue of concern.It not only eases the environmental and energy consumption caused by washing,but also effectively screen and dispel each species of environmental fomes to avoid hurt to human body.The self-cleaning function is mainly realized by physical-superhydrophobic surface technology and chemical-photocatalytic surface treatment technology,but both methods have certain limitations.Superhydrophobic surfaces mostly contain fluorine element,which poses a serious threat to the ecological environment.Grease is also easy to destroy its hydrophobic properties.Although photocatalysis can degrade organic fomes,it takes a long time.At the moment,vast majority self-cleaning fabrics use unitary superhydrophobic or photochemical catalysis technology,which has problems such as complicated process design and limited self-cleaning ability.In this paper,fluorine-free and environmentally friendly organic silicone materials polydimethylsiloxane（PDMS）and titanium dioxide supported bamboo charcoal particles（TiO₂-BC）were selected to jointly construct the superhydrophobic photocatalytic surface of the fabric.The research contents are as follows:TiO₂-BC composite particles were prepared by"solution-sol"method,and then treated with PDMS on cotton fabric by dipping,rolling and baking.The surface contact Angle of cotton fabric after finishing was measured.The results showed that after TiO₂-BC/PDMS finishing,when the amount of PDMS was 8 m L and the mass of TiO₂-BC was 0.5 g,the water contact Angle increased to 155°,achieving the superhydrophobic effect.At the same time,the amount of TiO₂ was saved at least87.5%.Scanning electron microscopy（SEM）was used to observe that the surface roughness of the treated cotton fabric increased obviously,and a dense hydrophobic film was formed on the surface of the fabric after hydrophobic finishing.X-ray photoelectron spectroscopy（XPS）showed that the treated fabric showed obvious characteristic peaks of Si2p and Si2s at 102 e V and 150 e V,while the content of O decreased from 36.15%to 24.25%,respectively.Tiand Si elements appeared in the treated fabric.The change of the concentration of these elements improves the hydrophobic properties of the fabric surface.In addition,the self-cleaning and wearability of the finished fabric were tested,and it was found that there was no significant change in the stain resistance,wear resistance,water resistance and air permeability of the fabric,which were within the acceptable range.The photocatalytic tests of methylene blue（MB）and rhodamine B（Rh B）on TiO₂-BC composite and TiO₂-BC/PDMS cotton fabric were carried out.The results showed that for methylene blue,the degradation rate could reach 100%after adding10-50 mg TiO₂-BC for 45 min at most,and the degradation rate of TiO₂-BC/PDMS cotton fabric could reach 83.3%after 6 h of light.For rhodamine B,the degradation rate could reach 100%after adding 10-50 mg TiO₂-BC for 50 min at most,and the degradation rate of TiO₂-BC/PDMS cotton fabric could reach 81.3%after 10 h of light,showing excellent photocatalytic activity and meeting the requirements of super-hydrophobic photocatalytic self-cleaning fabric.