Preparation And Properties Of Superhydrophobic Photocatalytic Oil-water Separation Cotton Fabric Based On Activated Carbon Supported Titanium Dioxide

Cotton fabric has become one of the indispensable materials in people’s daily life because of its soft,breathable,portable and recyclable properties.However,the inherent hydrophilicity of cotton fabric makes its practical application very limited.In recent years,with the continuous development and diversified needs of superhydrophobic cotton fabrics,the development of superhydrophobic cotton fabrics with photocatalytic degradation of organic pollutants and oil-water separation function has become a key field of attention of researchers,which can not only reduce the harm of water and environmental resource pollution caused by washing and oil leakage,It can also degrade all kinds of toxic,carcinogenic and teratogenic chemicals in a green and efficient manner,so as to reduce the irreversible damage caused by external environmental pollutants to human health.At present,the surface of most of the superhydrophobic cotton fabrics contains fluorine,and there are some problems such as high preparation cost and complicated process.In this paper,the fluorine-free and environmentally friendly silane coupling agent cetyltrimethoxy-silane（HDTMS）,methyl trimethoxy-silane（MTMS）and activated carbon supported titanium dioxide（TiO₂-AC）nanocomposites were selected to construct super hydrophobic cotton fabric with photocatalytic and oil-water separation properties.TiO₂-AC nanocomposite particles were prepared by sol-gel method,and then long carbon chain siloxane was formed by hydrolyzing and crosslinking with HDTMS and MTMS,which was coated on the surface of the fiber by the process of dipping and high temperature curing.The physical and chemical analysis of raw cotton fabric and cotton fabric with different finishing methods was carried out.The results show that:at room temperature,when the amount of TiO₂-AC nanocomposite is 0.7 g,the amount of HDTMS is 400μL,and the amount of MTMS is 200μL,the impregnation time is 30 min,and the high temperature curing time is 150℃for 2 min,the surface water contact angle of the modified cotton fabric was 158°,reaching the superhydrophobic state.5 g TiO₂ particles and 0.7 g TiO₂-AC composites can achieve the same superhydrophobic effect,thus saving at least 86%of the amount of TiO₂ particles.Using scanning electron microscope（SEM）and atomic force microscope（AFM）,it was observed that the surface roughness of the finished cotton fabric was increased by more than 2.8 times,a tight water-repellent membrane was observed on the surface of the modified fabric.At the same time,the surface of TiO₂-AC/HDTMS modified cotton fabric detected very obvious characteristic peaks of Si2p and Si2s.After finishing,the content of C element increased from60.96%to 76.10%,the content of O element decreased from 36.90%to 14.11%,and Ti element also appeared on the surface of the modified cotton fabric.In addition,a series of wear performance tests including self-cleaning were carried out on the modified cotton fabric,and the test results showed that the modified cotton fabric had excellent anti-fouling,anti-mechanical wear,anti-washing,anti-acid and alkali corrosion and air permeability.The photocatalytic tests of methylene blue（MB）dyeing solution and rhodamine B（Rh B）dyeing solution were carried out for the TiO₂-AC nanocomposite,TiO₂/HDTMS modified cotton fabric and TiO₂-AC/HDTMS modified cotton fabric,and the oil moisture of the TiO₂/HDTMS modified cotton fabric and TiO₂-AC/HDTMS modified cotton fabric leave the test.The results showed that the degradation rates of MB dyeing solution and Rh B dyeing solution of TiO₂/HDTMS modified cotton fabric reached 55.01%and 33.39%respectively after 5 hours of simulated illumination.The degradation rates of MB dyeing solution and Rh B dyeing solution of cotton fabric modified by TiO₂-AC/HDTMS reached 90.01%and 76.53%,respectively.The cotton fabric modified by TiO₂-AC/HDTMS showed excellent photocatalytic performance.The separation efficiency of n-hexane and dichloromethane of TiO₂-AC/HDTMS modified cotton fabric is 99.2%and 98.7%respectively,which makes it also have broad application prospects in the field of oil-water separation and broadens its application field in textile and clothing fabrics.