Fabrication Of Special Wettable Fabric With Weft Backed Weave For Oil/Water Separation

Oily water has been an important issue in our daily life,which need to be urgently solved.Traditional ways to solve the problem are chemical,physical and biologic which obtains the shortcomings of high energy-consumption and low oil/water separation efficiency.Inspired by the special wettability of lotus leaves with high water repellence and fish with hydrophilic properties,preparation of superhydrophobic and superhydrophilic materials has been gained much attention.Fabric with porous structure had been paid much attention for their potential use to the oil-water separation.By enhancing the surfaces' roughness of the fabric or decreasing the surface energy,fabric with superhydrophobic properties was obtained for oil/water separation;By increasing the numbers of hydrophilic groups of surface,fabric with superhydrophilic properties was gained for oil/water separation;By the single-faced hydrophobic treatment of the fabric,fabric with Janus properties was acquired for oil/water separation.Woven fabric that containing the weft backed weave is made up by the interweaving of weft yarns and warp yarns with a certain rule.Weft backed weave contain two common or different weft yarns and warp yarns,weft yarns interweave with warp yarns to construct the surface weave.By adjusting the wetting ability of the weft yarns and warp yarns,fabric with different wettability using for oil/water separation were obtained.In this work,fabric containing hydrophobic,hydrophilic and Janus properties with weft backed weave was fabricated by the fabric structure design,Field emission scanning electron microscopy was used to characterize of the surface morphologies of the yarns.And the chemical composition was investigated by using energy-dispersive X-ray spectroscopy.SEM images were used to make sure the structure of weft backed weave.The water contact angle was measured with a contact angle meter.Magnifier was used to test the warp and weft densities.Venire caliper was served to measure the thickness of the fabric.By employing the hydrophobic polyester yarns as warp yarns,hydrophobic cotton yarns as weft yarns;hydrophobic fabric with weft backed weave was fabricated.Comparing with the fabric without hydrophobic treatment,hydrophobic fabric had a contact angle(CA)higher than 150 o,showing good water repellency.Oil/water separation experiment of hydrophobic fabric with weft backed weave indicated the achievement of separation of oil and water mixtures,and the separation efficiency is 96%;subsequently fabric with weft backed weave can achieve repeated oil/water separation experiment of higher than 10 times,keeping the high water repellency of 150 o and separation efficiency of 96%.By using the hydrophilic polyester yarns as warp yarns,hydrophilic cotton yarns as weft yarns;superhydrophilic fabric with weft backed weave was fabricated.The fabric is superhydrophilic and oleophilic in air,while oleophobic underwater.Oil/water separation experiment of the fabric shows the achievement separation of different oil/water mixtures,heptane/water,decode/water,with separation efficiency of higher than 96%.Subsequently fabric with weft backed weave can achieve repeated oil/water separation experiment of higher than 50 times,keeping unfueled by impurities and oil and separation efficiency of 96%.By applying the hydrophobic polyester yarns as warp yarns,hydrophobic and hydrophilic cotton yarns as weft yarns,fabric with asymmetric wettability was fabricated.One surface of the fabric with high water repellency is hydrophobic,the other face is hydrophilic that absorbs water while oleophobic that repels water underwater.The single-faced superhydrophobic fabric has been successfully used for the oil-water separation to achieve the water-removal and oil-removal.The separation of oil from oil/water mixtures could be achieved by placing the hydrophobic face on the top,and the switched separation of water from oil/water mixtures could be further realized by placing the hydrophilic face on the top after pre-wetted treatment.Moreover,each separation process with the separation efficiency is above 95%.