具有微纳复合仿生结构的油水分离膜材料的制备及性能研究

发布时间：2018-06-09 02:39

本文选题：油水分离 + 微纳复合仿生结构　；参考：《新疆大学》2015年硕士论文

【摘要】：油水分离是工业领域面临的问题之一,而油水混合物的多样性增加了分离的难度。相较于传统油水分离手段,膜技术由于其能耗低、分离效率高得到了广泛关注和应用。微纳复合仿生结构的引入,大大提高了分离膜的分离效率。针对油水混合物形式的多样性,本论文设计制备了三种不同具有微纳复合仿生结构的油水分离薄膜。1.通过戊二醛对半互穿网络(semi-IPN)凝胶涂层中的线型高分子聚乙烯醇(PVA)进行交联,得到了具有互穿网络(IPN)凝胶涂层改性的不锈钢油水分离网膜。相较于semi-IPN凝胶涂层,IPN凝胶涂层具有更加粗糙的表面,这使其水下疏油性能得到提升。交联改性后网膜的接触角由141.50±0.50o增加至153.92±1.08o,同时对简单油水混合物的分离效率也由99.7%提升至99.8%。同时IPN凝胶涂层对于基底不锈钢网的粘附力更强,自身的强度也更大,最大压缩强度为97.00±7.69 kPa。2.通过Pickering乳液法制备了尺寸在百微米级的具有核壳结构的聚丙烯酰胺微凝胶,然后控制PVA湿膜的厚度制备了具有跨膜结构的油水分离膜。其中跨膜结构的存在大幅提高了薄膜的水通性能,相较于PVA薄膜水通量提升至2倍。同时微凝胶的核壳结构赋予了薄膜微纳复合仿生结构的表面,水下接触角同样从133o增加至142o。在常压和0.01 MPa两种操作压力下薄膜能够实现对水包油不稳定乳液的油水分离。在加压条件下,分离通量最高能达到1000 Lm-2h-1。对于所测试的大多数乳液,分离后的水中油含量小于100 ppm。3.在一定湿度环境下通过醋酸纤维素(CA)溶液的相分离和硅烷偶联剂的水解缩合反应制备了CA油凝胶,在溶剂置换后常温常压下干燥得到了有机无机复合气凝胶薄膜。薄膜表面具有微纳复合仿生结构,水滴在薄膜表面的接触角达到147.2±0.3o,同时油滴能在其上铺展。该气凝胶薄膜具有亚微米级的孔道尺寸,能够对稳定的油包水乳液有效分离。在0.01 MPa操作条件下,对直径约330 nm的油包水乳液分离通量达到1000-3000 Lm-2h-1,滤液中水含量低至100 ppm以下。
[Abstract]:Oil-water separation is one of the problems in industry, and the diversity of oil-water mixture increases the difficulty of separation. Compared with traditional oil and water separation methods, membrane technology has been widely concerned and applied because of its low energy consumption and high separation efficiency. The introduction of micro-nano composite bionic structure greatly improved the separation efficiency of separation membrane. In view of the diversity of oil-water mixture, three kinds of oil-water separation films with micro-nano composite bionic structure were designed and fabricated in this paper. The linear polymer polyvinyl alcohol PVA (PVA) in semi-IPN gel coating was crosslinked by glutaraldehyde, and the oil-water separation omentum of stainless steel modified by IPN gel coating was obtained. Compared with semi-IPN gel coating, the surface of IPN gel coating is more rough, which improves its hydrophobic performance. The contact angle of the cross-linked modified omentum was increased from 141.50 卤0.50o to 153.92 卤1.08o. the separation efficiency of the simple oil-water mixture was also increased from 99.7% to 99.8%. At the same time, the adhesive force of IPN gel coating to stainless steel mesh is stronger, and the strength of IPN gel coating is larger, the maximum compressive strength is 97.00 卤7.69kPa.2. Polyacrylamide microgels with core-shell structure were prepared by Pickering emulsion method. The oil-water separation membranes with transmembrane structure were prepared by controlling the thickness of PVA wet film. The existence of transmembrane structure greatly improved the water permeability of the film, and compared with PVA film, the water flux increased to 2 times. At the same time, the core-shell structure of the microgel gives the surface of the film micro-nano composite bionic structure, and the underwater contact angle also increases from 133o to 142o. The oil-water separation of the oil-in-water unstable emulsion can be realized by the thin film under two operating pressures of normal pressure and 0.01 MPA. The maximum separation flux was 1000 Lm-2h-1 under pressure. For most of the emulsions tested, the oil content in the separated water was less than 100 ppm. 3. CA oil gel was prepared by phase separation of cellulose acetate (CA) solution and hydrolysis and condensation reaction of silane coupling agent under certain humidity. The organic-inorganic aerogel film was obtained by drying at room temperature and atmospheric pressure after solvent replacement. The surface of the film has a micro-nano composite bionic structure, and the contact angle of water droplets on the surface of the film is 147.2 卤0.3 o.The oil droplet can spread on the surface of the film. The aerogel film has sub-micron pore size and can be effectively separated from stable oil-in-water emulsion. Under the operating condition of 0.01 MPA, the separation flux of oil-in-water emulsion with diameter of 330nm was 1000-3000 Lm-2h-1, and the water content of filtrate was lower than 100 ppm.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.893

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