Preparation And Application Of PH-responsive Hierarchical Structure Material For Oil-water Separation

With the increasing demand for offshore oil production,the rapid development of modern industries,oil field leakage incidents and improper discharge of organic matter in industrial production frequently occur,causing serious pollution to the ecological environment and even threatening human health.The traditional oil-water separation technology and the oil-water separation material have low recycling rate,poor separation effect,high residual rate and single separation system,which cannot meet the application requirements of oil-water separation of various complex systems,therefore,a fast,efficient and intelligent response material will have broad application prospects.In this paper,polyaniline(PANI)composite with micro/nano hierarchical structure was prepared by in-situ chemical oxidation polymerization for its reversible doping and dedoping properties.The effects of oxidant dosage,aniline concentration,doping acid concentration and polymerization temperature on the wettability and the morphology of PANI composites were investigated by means of controlled variable method.The structure,wettabiity and micromorphology of the prepared PANI composites were characterized and analyzed by means of fourier transform infrared spectroscopy(FT-IR),optical contact angle measuring instrument and scanning electron microscope(SEM).Optimal process conditions for highly hydrophobic PANI micro/nano hierarchical structure composites was determined.PANI oil-water separation composite material were prepared by polymerizing aniline in situ on the surface of various materials such as polyester mesh,sponge,cotton and cotton fabric using the above synthetic process,which has intelligent pH responsiveness.The superhydrophobic-superlipophilic PANI composite can be quickly switched to superhydrophilic-underwater superoleophobicity in a system with pH=13,under acidic conditions,the material can be quickly recover to super hydrophobic-superlipophilic,so it can selectively separate oil and water,and can successfully separate oil/water/oil three-phase complex system.PANI/sponge composites can quickly absorb different types of oils and have an oil absorption capacity of up to 95 g/g,and the oil absorption rate is fast.After 20 cycles of recycling,the Oil absorption capacity can still reach 72 g / g.The oil adhesive force of the material is low,and the absorbed oil can be released without being squeezed by external force.Investigating the wettability of hot water,cold water and salt water on the surface,PANI hierarchical structural composites exhibit excellent stability and can be widely used in harsh external environments.