| Nowadays, petroleum has gradually become an indispensable resource for the development of human society. However, high water content in oil production and the frequent occurrence of oil spill accidents in the sea will affect the use of petroleum. How to reduce the water content of oil in the mining process and the solving of the oil spill accidents has gradually become a hot topic. Therefore, the study of oil / water separation is of great significance. In recent years, porous filter material with special wettability, which is different in the wetting property of oil and water, has realized the effective separation of oil and water, and has gradually become a new and efficient method of oil/water separation. This article will continue to start from the surface wettability. Based on the modification of the surface of three-dimensional porous material-the copper foam, we obtained the copper foam with special wetting property and studied its oil/water separation performance. Main work content is as follows:1. Using polyurethane foam as substrate, after pretreatment, conductive adhesive coating, electroplating, substrate sintering and reduction thermal treatment, a layer of copper was deposited on the surface of polyurethane substrate and the copper foam with different pore sizes and thickness was obtained.2. Preparing super-hydrophobic and super-oleophilic copper foam with solution dipping method. Firstly, a layer of petal like coarse structure was constructed on the surface of the copper foam by soaking the mixed solution of sodium hydroxide and potassium sulfate, then using the low surface energy substance twelve-thiol to reduce the surface energy. In the air medium, the contact angle of water on the surface of copper foam sample is 155°, and the contact angle of the oil is close to 0. The obtained copper foam has high oil/water separation efficiency and successfully achieved its application in oil/water separation.3. The mechanism of oil/water separation on the surface of wettability was studied. In the course of oil/water separation, the wetting process between the sample and the oil can be divided into three parts: In the first part, the samples are not wetted by oil / water mixture, the water and oil are separated due to the super-hydrophobic properties of the samples, so that the oil/water separation can be realized; In the second part, the sampls are completely wetted by oil/water mixture, and the super-hydrophobicity of the samples can not be expressed. The samples depend on their super-hydrophobicity to exhibit the property of super-hydrophobicity, still have the function of oil / water separation. In the third part, the samples are part wetted by oil/water mixture, the oil wetted and not wetted parts of the samples realize oil/water separation respectively due to their super-hydrophobicity and super-hydrophobicity.4. Based on the oil/water separation mechanism of super-hydrophobic and super-oleophilic copper foam, the super-hydrophillic and super-oleophilic copper foam samples were obtained after soaking the copper foam samples with sodium hydroxide and potassium hydroxide solution. The obtained copper foam has super-oleophobic property underwater because of its super- hydrophilicity. After pre-wetted by water, the samples still have high efficiency of oil/water separation. |
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