The Fabrication Of Superwettability Materials On Metal Substrate For Their Application To Oil/Water Separation

Recently,with the development of petroleum industry and increase of oil spill accidents,oil/water separation has attracted worldwide attention.Since oil/water separation is largely governed by the interfacial phenomenon,the utilization of super-wettability to design novel materials is a facile and effective approach.Lots of materials possessing superhydrophobicity/superoleophilicity can separate oil from water while the water phase retained above the mesh?named as?oil-removing?types of materials?.However,the materials involved in above methods can be easily fouled by the adherent oil during the separation process,thus resulting in limiting their applications.Furthermore,such filter materials are not suitable for the gravity-driven removal of light oils?which are less dense than water?from mixed solutions.Unfortunately,most oils are lighter than water.Now,materials with underwater superoleophobicity have attracted great attention in the separation field,because these materials can allow the water phase to easily penetrate through the materials,while the oil phase to be repelled completely?termed as?water-removing?materials?.However,such?water-emoving?materials are not the best choice for separating heavy oil from water,because heavy oil can form a barrier laid on the materials surface and prevent the permeation of water phase.Although those materials have been extensively applied in oil/water separation,the preparation process is usually complex and easily causes environmental pollution.The choice of materials will depend on the density of the oil and the composition of the oil/water mixture.Therefore,there is an urgent demand to exploit the device that should have the versatility to handle both options in one single facility.The main contents and results about this dissertation are summarized as follows:?1?CuO coated foam with superhydrophobic and superoleophilic property has been successfully fabricated via a simple solution-oxidation process.Based on a design of box,the superhydrophobic Cu foam can separate all kinds of oils regardless of the heavy oil or light oil in the mixture with the separation efficiency up to 97%,the advantage of which the other 2D superhydrophobic oil filtration material did not possess.In addition,the box manufactured superhydrophobic and superoleophilic CuO coated foam could continuously capture and removal the oil from water surfaces under a continuous vacuum regime.When vacuum degree was 30 kPa,the separation velocity can be 5 mL s^-1,showing a high-speed separation process.?2?We showed underwater superoleophobic Ag coated meshes,which were prepared by a facile galvanic exchange reaction.The meshes were then used to study oil/simulated seawater separation.The separation efficiency of above 94.0%could be achieved.Moreover,the Ag coated mesh can maintain a high separation efficiency after 45 cycles.Furthermore,the silver coated mesh can exhibit the excellent environmental stability under the harsh conditions.?3?Responsive waste potato residue coated-mesh?PRCM?was demonstrated for the first time for selective oil/water separation without any further chemical modification,which was prepared by spraying waste potato residue powders?PRP?on the stainless steel mesh.After prewetted,the water phase can be removed from the light oil/water mixture with a high separation efficiency.And,heavy oil can be removed from the oil/water mixture via the heavy oil prewetted PRCM.The PRCM showed a high separation efficiency of above 97.7%for a series of oil/water mixtures.In addition,the PRCMs can maintaine a high separation efficiency of over 98.5%and a stable recyclability after 40separation cycles for a kerosene/water mixture.Finally,we used some wetting models of PRCM to analyse the phenomenon of superwettability proving the feasibility of oil/water separation in theory.