特殊润湿性金属筛网的制备及其在油水分离方面的应用

发布时间：2018-03-08 11:43

本文选题：仿生　切入点：超疏水　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着全球工业化进程的不断加快,石油开采、冶金、炼钢、制革、化工、原油泄漏等领域每天都会产生大量的含油废水,这些含油废水的直接排放不仅是不可再生资源的严重浪费,而且直接对环境造成污染,间接地影响到人类的健康和生活。因此,对含油废水进行分离处理无论从节约资源还是环境保护方面都具有重大意义。含油废水常用的处理方法有物理法、化学法、生物法,这些方法都具有各自的优点,但其在占地面积、耗能、分离效率方面有待进一步提高。近些年来,人们通过对荷叶表面形貌和化学组成进行研究,发现荷叶表面是由一层乳突状的蜡质结构组成。以荷叶为代表的植物表面具有超疏水表面引起了人们极大的兴趣。由仿生学的原理,想要获得超疏水性能需要满足两个必要条件:增大表面粗糙度和降低表面自由能。受此启发,大量的研究致力于超疏水材料的开发,并成功的应用在了油水分离方面。本文成功制备出了超疏水Co(OH)_2/HDTMS不锈钢网、超亲水/水下超疏油Co_2(OH)_2CO_3(CoOC)镍网和超疏水CoOC/HDTMS镍网,并设计了一套油水分离装置对其油水分离性能进行了研究。本文以不锈钢网为基体,在其表面用电化学单极脉冲法合成一层具有蝴蝶翅膀状的Co(OH)_2粗糙结构,再用具有低表面能的十六烷基三甲氧基硅氧烷(HDTMS)进行修饰,最终获得了超疏水性能。该超疏水筛网表面水的接触角可以达到157.9°,油的接触角为0°,因此可以被成功的应用在油水分离方面。实验结果表明,该不锈钢筛网对正己烷/水、异辛烷/水、石油醚/水、汽油/水、柴油/水的分离效率可高达99.5%以上,并且重复使用25次以后(以分离正己烷/水的混合物为例),筛网依然可以保持一个较高的超疏水性能和分离效率。并且,该筛网具有良好的耐侯性能,这是由于修饰后的硅氧烷层具有天然的抗原子氧化能力,可以有效地防止外界氧化物质的侵入,这对于处理有腐蚀性的油水混合物能起到很重要的作用。此外,文中对超疏水筛网的机械性能也进行了考察。以镍网为基体,在其表面用水热法合成一层片状的碱式碳酸钴(CoOC)粗糙结构,该表面水的接触角为0°,而水下油的接触角为158.1°,表现出优异的超亲水/水下超疏油性能。利用十六烷基三甲氧基硅烷(HDTMS)对CoOC镍网进行化学修饰后,获得了超疏水/超亲油表面,该表面对水的接触角为157.2°,油的接触角为0°。最后,本文设计了一套连续油水分离装置,将以上两种具有相反润湿性能的筛网夹在装置的两边,实现对油水混合物的连续分离。该方法克服了单一膜油水分离装置间歇操作的处理量小,净化程度低等缺点,扩大了其应用范围。更重要的是,由于修饰后存在于镍网表面的Si-O-Si键具有较高的键能,超疏水筛网的耐热性能得到了很大的改善,这为较高温度下含油废水的分离提供了一个新方法。
[Abstract]:With the acceleration of the global industrialization process, oil extraction, metallurgy, steelmaking, tanning, chemical industry, crude oil leakage and other fields produce a large amount of oily wastewater every day. The direct discharge of these oily wastewater is not only a serious waste of non-renewable resources, but also a direct pollution to the environment, indirectly affecting the health and livelihood of human beings. The separation and treatment of oily wastewater is of great significance in terms of saving resources and protecting the environment. The common methods for treating oily wastewater are physical, chemical and biological methods, all of which have their own advantages. In recent years, the surface morphology and chemical composition of lotus leaves have been studied. It is found that the surface of lotus leaf is composed of a layer of papillate waxy structure. The superhydrophobic surface of the plant surface represented by the lotus leaf has aroused great interest. In order to obtain superhydrophobic properties, two necessary conditions need to be satisfied: increasing surface roughness and reducing surface free energy. Inspired by this, a great deal of research has been devoted to the development of superhydrophobic materials. In this paper, the superhydrophobic Co(OH)_2/HDTMS stainless steel mesh, superhydrophilic / underwater super oil Cost2OHH / submersible Cos / 2CO3CoOC) nickel net and superhydrophobic CoOC/HDTMS nickel net have been successfully prepared, and have been successfully applied to the separation of oil and water. A set of oil-water separation device was designed to study its oil-water separation performance. In this paper, a layer of Co(OH)_2 rough structure with butterfly wings was synthesized on the surface of stainless steel mesh by electrochemical monopole pulse method. Then modified with hexadecyl trimethoxysiloxane (HDT) with low surface energy, The contact angle of water on the surface of the superhydrophobic screen can reach 157.9 掳, and the contact angle of oil is 0 掳, so it can be successfully applied to the separation of oil and water. The experimental results show that the stainless steel screen is suitable for n-hexane / water. The separation efficiency of isooctane / water, petroleum ether / water, gasoline / water, diesel oil / water can be over 99.5%, And after 25 times of repeated use (taking the mixture of n-hexane / water as an example, the screen mesh can still maintain a high superhydrophobic property and separation efficiency.) moreover, the screen has good weathering resistance. This is because the modified siloxane layer has the natural ability to resist atomic oxidation, which can effectively prevent the external oxidizing substances from invading, which can play a very important role in the treatment of corrosive oil-water mixtures. In this paper, the mechanical properties of superhydrophobic sieve mesh were also investigated. Using nickel mesh as substrate, a layer of basic cobalt carbonate CoOC rough structure was synthesized by hydrothermal method on its surface. The contact angle of the surface water is 0 掳, and the contact angle of the underwater oil is 158.1 掳, showing excellent super hydrophilic / underwater super hydrophilic / ultra hydrophobic properties. After chemical modification of the CoOC nickel mesh with hexadecyltrimethoxysilane, the superhydrophobic / super oil-lipophilic surface was obtained. The contact angle of the surface to water is 157.2 掳, and the contact angle of oil is 0 掳. Finally, a set of continuous oil-water separation device is designed. The continuous separation of oil-water mixture is realized. This method overcomes the disadvantages of the batch operation of single membrane oil-water separation device, such as small treatment capacity and low purification degree, and expands its application scope. The heat resistance of superhydrophobic sieve mesh has been greatly improved due to the high bond energy of Si-O-Si bond existing on the surface of nickel mesh after modification, which provides a new method for the separation of oily wastewater at higher temperature.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ051.8;X703

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