PDMS/ZnO Polyurethane Foam And Its Oil-water Separation Study

In recent years,with the development of the petrochemical industry,leakage of oil products and organic solvents occurred from time to time,which not only caused a lot of waste of resources,but also caused serious water pollution when flowing into water.Using oil-absorption materials is considered to be a fast and effective way to treat oil-contaminated water.Polyurethane sponge oil-absorption material's inside like "honeycomb",which makes the polyurethane sponge has wealth holes,and the holes communicate with each other.The polyurethane sponge has high porosity,low density,high elasticity,etc.,and it's considered to has a very high application value.Because the polyurethane sponge surface has a hydrophilic group,so it's oil-water selectivity is undesirable and needs to be hydrophobic modified.The purpose of this paper is to develop a hydrophobic modification method with simple process,low cost and easy industrialization,and to prepare a hydrophobic polyurethane sponge oil-absorption material with high oil-water separation performance.Firstly,ZnO thin film was constructed on the sponge by means of gel-sol method,and then surface-modified with polydimethylsiloxane(PDMS),the PDMS/ZnO sponge was finally obtained.Through the analysis of the stability of the sol solution,the micro morphology of Zinc Oxide coating,the hydrophobicity of PDMS/ZnO sponge after the hydrophobic modification,and the stability of the hydrophobicity.The optimal experimental conditions for the film were as follows: the ratio of water to ethanol is 1:9,the precursor concentration is 0.075 g/L,the reaction temperature is 60-70°C,the mass ratio of Sodium dodecyl sulfate(SDS)to the precursor is 0.01,the volume fraction of silane coupling agent(KH-550)is 0.5%,PDMS is dissolved with hexane and the volume fraction is 0.4%;Secondly,through the adsorption experiment of pure oil,it is found that the saturated The adsorption rate of modified sponges for different oils and organic solvents is between 25 and 51 g/g,and the adsorption ratio becomes larger with the increase of concentration.The utilization rate is about 90%,which indicates the internal space of the sponge is fully utilized.Compared with the original sponge,the modified sponge has a slightly increased adsorption rate and volume use efficiency,indicating that the modification improves the lipophilicity of the Polyurethane sponge.Finally,this paper investigated the adsorption and separation performance of PDMS/ZnO sponge for kerosene,which floating on the water surface and dispersed in water b.When treating the floating oil system,as the thickness of the oil film on the surface increases,the adsorption rate of the sponge increases,and the unit water absorption decreases.As the oil absorption increases,the purity of the recovered kerosene increases,and the purity of the recovered kerosene is more than 99%,which indicates that the sponge has excellent separation performance for slick oil;when the dispersed oil is treated,the unit water absorption amount increases with the concentration of dispersed oil.Basically,the separation efficiency increases first.When the concentration is too high,the sponge adsorption saturation,the separation efficiency will drop.When the concentration is 15 g/g,the oil-water separation efficiency is 86.6%,and the recovered kerosene purity is about 95%.Through the sponge reusability analysis,there is no significant reduction in performance after using 20 times,and the unit oil absorption attenuates about 30% after using 60 times,which indicates that the PDMS/ZnO sponge has a good recycling performance and can be used as a durable oil-absorption material to treat oil-water mixtures.