Preparation And Study On Oil-water Separation Property Of The Magnetic Composite Sponge

Environmental problems were frequently caused by oil spills.The development of special performance oil-water separation materials is imminent.Simple preparation of low-cost magnetic oil-water separation materials is an effective way to solve these problems.In this paper,magnetic superhydrophobic sponges and magnetic sponge with pH responsewere prepared by immersion method with commercial polyurethane?PU?sponges as the base,and stearic acid?SA?,tetrabutyl orthotitanate?Ti?OBu?4?,lauric acid?LA?and magnetic nanometer iron trioxide particles as the main modifiers.The oil-water separation performance of magnetic superhydrophobic sponges and magnetic pH response sponges were studied.The main research contents are as follows:1.Preparation and properties of magnetic super-hydrophobic PU spongesMagnetic nano-iron oxide particles were fixed on the three-dimensional skeleton of the PU sponges,then polydopamine?PDA?film was formed on the sponge surface by self-polymerization of dopamine.Then,the magnetic PU composite sponge was immersed in SA to form a layer of low surface energy polymer.The prepared super-hydrophobic magnetic sponges had super-hydrophobic and magnetic properties.Characterization was performed by scanning electron microscopy?SEM?,Fourier transform infrared reflection?FTIR?,X-photoelectron spectroscopy?XPS?,energy spectroscopy?EDS?and X-ray diffraction?XRD?.Then the magnetic performance of the composite sponge was researched,the results showed that the magnetic sponges after oil absorption can moved directionally under the action of external magnetic field.The experiment of oil-water separation showed that the composite sponge can separate many kinds of oil and organic solvents from water.In addition,in the vacuum pump system,the composite sponge could continuously separated a large amount of oil from water,and through multiple cycle experiments,it maintained good hydrophobicity and oil absorption capacity.2.Preparation and performance of magnetic pH response spongeThe magnetic nano-iron oxide particles were also fixed in the commercial PU sponges,and then a pH-responsive sponges were prepared by immersion in the prepared Fe₃O₄/LA-TiO₂ suspension.The morphology and composition of the sponges before and after modification were characterized by SEM,FTIR,XPS,EDS,and XRD.Modified Fe₃O₄/LA-TiO₂ pH response sponges had the properties that can switch between super-hydrophobic/super-lipophilic and super-hydrophilic/super-oleophobic at different pH values.The Fe₃O₄/LA-TiO₂ pH response sponges had super hydrophobicity/super lipophilicity when pH=7 and can be used for oil separation in oil-water mixture.The surface of pH response sponged were super hydrophilic and underwater oleophobic when pH=12 or higher,which can be used for water separation in oil/water mixture.In addition,pH response sponges also had good magnetic performance,it can moved directionally under the action of external magnetic field.In the experiment of oil-water separation,it had good separation efficiency and recyclability,and was suitable for the separation of most oil and various organic solvents and water.In this paper,the magnetic composite sponges were based on PU sponge with vesicular structure,which can store a large amount of oil and provide a congenital advantage for oil-water separation.Therefore,the prepared composite sponges not only had good oil absorption effect,but also could continuously separate a large amount of oil-water mixture.After the oil absorption reached saturation,it can be quickly and conveniently recycled by an artificial magnetic field,which provided great convenience for the recovery of marine oil spill.In addition,compared with the preparation methods of the composite sponge reported in the literature in recent years,the method in this article had the following advantages:mild experimental conditions,no need for high temperature vacuum environment,low energy consumption;simple operation of oil-water separation,good repeatability;simple preparation route and low cost;environmentally friendly.So it had potential application value in the field of oil-water separation.