Biomimetic Preparation And Properties Of Special Wettable Porous Materials

With the development of modern society and industry,it not only brings people convenient life,but also brings a lot of environmental pollution problems.The large amount of oil-bearing wastewater discharge has a huge impact on the normal life of human beings and the ecological environment of the earth.Therefore,to achieve effective oil-water separation has become an urgent problem that must to solved.The oil-water separation method people use now mainly include chemical method(dispersion,solidification),physical method,in-situ combustion method and bioremediation method.Although these methods can achieve the purpose of oil-water separation,they still have some disadvantages,for example,low separation efficiency,low selectivity,slow filtration speed,creat harmful substances,secondary pollution,complex operation and high cost.In this paper,cotton,sponge,mesh and other porous materials with low cost and easy to preparation are used as substrate to prepare oilwater separation materials by changing the surface wettability.The main research include the following two aspects.(1)The commercial porous materials were immersed into polydimethylsiloxane(H2N-PDMS-NH2)and dopamine(DA)solution,different substrates(cotto,sponge,nylon,silk,copper mesh,wood)can show superhydrophobic properties after 30 minutes of reaction under ultrasonic conditions.In the preparation process,ultrasonic can significantly accelerate the formation of micro-nano structure on the surface of substrate,and the alkalinity required for DOPA polymerization is also provided by H2NPDMS-NH2,without the addition alkaline substance.What’s more,the superhydrophobic substrate can recover its superhydrophobic property spontaneously after being destroyed by air plasma or polluted by amphiphilic solvent,which shows that the superhydrophobic coating prepared by this method has the function of self-healing.The superhydrophobic cotton and copper mesh are used as oil absorption and oil filtering materials to separate the oil/water mixture The efficiency is above 95%.(2)Using cheap and readily available commercial copper mesh as the substrate and using thioacetamide(TAA)as the S source,the copper sulfide(CuSx)is grown in situ on the copper mesh substrate by a solvothermal "one-step method",which Increase the surface roughness of the copper mesh to form a super-hydrophilic/underwater super-oleophobic surface.With further research,the Cu/CuSx composite mesh in a super-hydrophilic state can be converted between super-hydrophobic and superhydrophilic through simple steps,which can be applied to oil-water separation in various conditions;CuSx on the surface of the Cu mesh has excellent photocatalytic performance,which can effectively degrade organic dyes and pollutants on the surface of the Cu/CuSx composite mesh.In addition,the Cu/CuSx composite mesh also has excellent light-to-heat conversion ability,and has potential for application in light-heat sterilization.