共查询到19条相似文献,搜索用时 140 毫秒
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《材料导报》2020,(17)
含油污水,特别是油/水乳液的分离是世界性的挑战。膜分离法由于具有分离效率高、能耗低、易于操作等特点,在油水分离领域具有较大的优势。超亲水/水下超疏油材料是"除水型"特殊润湿性材料,与超疏水-超亲油网膜相比,超亲水/水下超疏油膜在对抗有机污染和生物污染方面更具优势。超亲水/水下超疏油膜在处理含油污水过程中面临的主要问题有化学稳定性及膜污染。膜污染会导致分离效率及过滤通量下降等问题,缩短膜的使用寿命。因此,解决滤膜污染问题对污水处理至关重要。目前超亲水/水下超疏油材料改性的重点主要有三方面:提高过滤通量、抗污能力及设计合适的孔径。许多研究人员通过对疏水性基材(聚合物膜、金属筛网)进行改性以增强膜的亲水性和抗污性能,并取得了丰硕的成果。目前,聚合物膜改性方法主要分为基体改性和表面改性两种。基体改性即通过接枝共聚或共混等方法对膜进行亲水改性,然后将改性后的膜材料用于膜制备。表面改性是指对商业滤膜表面接枝极性单体或亲水单体。金属筛网常用的改性方法有化学刻蚀、表面涂覆、电化学沉积等。通过改变膜表面的化学组成和粗糙度调控滤膜的超润湿性能,从而提高膜的亲水性、分离效率和抗污性能。为了响应处理工业溢油及保护环境的要求,迫切需要开发具有高分离效率、高选择性和高稳定性的新型分离材料和技术,以应对日趋复杂的油水分离环境。本文以分离油水混合物及油水乳液的滤膜材料作为研究体系,首先介绍了超亲水/水下超疏油表面的理论基础及其构筑机理,然后从不同基材的角度介绍了油水分离功能材料的制备工艺及改性方法。本文全面综述了超亲水/水下超疏油金属网膜、聚合物膜材料和基于纳米材料的新型功能分离膜的研究进展,从润湿性、过滤通量、分离效率、抗污性能等方面综合评估了油水分离功能膜的性能,最后总结和展望了油水功能分离膜未来的发展趋势。 相似文献
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因含聚污水黏度大、流动性差、油类物质黏附性强,采用超滤膜对其进行处理时,油类物质极易在膜表面吸附进而铺展造成严重的膜污染.针对此,设计合成了同时具备亲水及低表面能疏油链段的聚乙二醇-聚甲基丙烯酸三氟乙酯(PEG-PTFMA)两亲改性剂,并采用共混-非溶剂诱导的相转化法制备了PES/PEG-PTFMA抗污染超滤膜.3次循环超滤实验表明,处理含聚污水时,改性PES超滤膜具备良好的抗污染及自清洁性能,与未改性膜相比,通量衰减率从88.0%降低至36.7%,简单水力清洗后通量恢复率从18.0%增高至99.0%以上,同时超滤膜还具备优良的截留性能,产水含油量可由初始的230 mg/L下降至几乎为0 mg/L,固体悬浮物的含量也从50 mg/L下降至约3 mg/L,均低于油田回注水水质指标要求.亲水及低表面能含氟链段在表面的富集显著提高了膜的亲水性及疏油性,从而赋予了膜优良的抗污染能力以及水力清洗时的污染释放自清洁能力. 相似文献
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选用两种分子量的聚醚砜(PES)为膜材料,以N-甲基吡咯烷酮为溶剂,分别以聚乙二醇(PEG400、PEG6000)和聚乙烯吡咯烷酮(PVP K30)为添加剂,用非溶剂致相分离法制备了超滤膜,研究了添加剂种类及浓度对不同分子量PES超滤膜性能的影响,利用相图及铸膜液黏度数据,从热力学、动力学、聚合物聚集体大小角度对实验现象进行了解释.结果表明,同种添加剂时,随PES分子量增大制得超滤膜的过滤通量增大、截留率降低.不同添加剂时,PES超滤膜对PEG20000溶液的通量按添加剂为PEG400,PEG6000,PVP K30的顺序依次增大.添加剂为PVP K30、PEG400时PES超滤膜的截留率大于添加剂为PEG6000时PES超滤膜截留率.铸膜液配方相同,添加剂浓度增大时,制得超滤膜的厚度增大,过滤通量增大、截留率降低. 相似文献
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《高分子材料科学与工程》2021,37(6)
利用朗缪尔探针和发射光谱法诊断远程氩等离子体,确定了离子密度和活性粒子的分布规律,以预测最佳改性区域;采用远程氩等离子体改性聚偏氟乙烯(PVDF)超滤膜,设计正交实验探究远程氩等离子体处理改性效果的最优工艺组合,并通过水接触角表征超滤膜改性前后的亲水性能;利用扫描电镜和X射线光电子能谱表征膜表面的形貌和化学成分变化,并通过拉伸性能测试表征改性后PVDF超滤膜强度。最后,通过海藻酸钠(SA)过滤实验评价膜改性前后过滤性能及抗污染性能。实验结果表明,远程氩等离子体改性的最优条件为,射频功率90 W、处理时间90 s、压强20 Pa、距放电中心40 cm处;PVDF超滤膜表面通过远程氩等离子改性后,其表面通过引入含氧、含氮基团提高了其表面亲水性能,水接触角从95.63°降至62.19°,且改性后的PVDF超滤膜最大拉伸强度由403.11 gf/cm~2增至为439.37 gf/cm~2。通过SA过滤实验,改性后的PVDF超滤膜具有良好的过滤性能和抗污染性能,其水通量和SA通量分别从123.36 L/(m~2·h),49.08 L/(m~2·h)增至151.98 L/(m~2·h),68.10 L/(m~2·h),截留率从77.35%增至87.25%,总污染率从72.50%降至60.20%。 相似文献
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集成膜过程污水深度处理工艺 总被引:3,自引:2,他引:1
介绍了集成膜过程及其在污水深度处理方面的应用.集成膜过程是将超遽/微遽与反渗透(或纳滤)相结合,形成能够满足各种回用目的的污水深度处理集成工艺.PVDF、PP、PE、PES等超滤/微滤膜,抗污染反渗透复合膜具有化学稳定性高、耐污染、装填密度高等特点,适宜于规模化污水处理.污水处理用超滤/微滤膜以中空纤维为主,系统技术采用了低压运行、频繁(气水、透过液)反冲、气水冲洗等抗污染工艺,能够维持稳定的通量、运行维护费用较低、产水质量稳定.二级出水的集成膜系统工艺已成熟并得以广泛推广,针对原废水的集成膜工艺(膜生物反应器 反渗透)还需要进一步的工程化研究. 相似文献
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以咔唑二硫代甲酸苄基酯为RAFT试剂引发苯乙烯(St)聚合,制备PSt大分子RAFT试剂,再调控大分子单体丙烯酸聚乙二醇单甲醚酯(A-mPEG)聚合,合成了窄相对分子质量分布、主链和支链不同、相对分子质量不同的两亲梳型嵌段共聚物Pst-b-P(A-mPEG).用1H-NMR和GPC对聚合物结构进行了表征.将制得的PSt-b-P(A-mPEG)与聚醚砜(PES)共混,经相转化法制备了超滤膜,研究了梳型嵌段共聚物中接枝密度与接枝链长度对膜抗污性能的影响.研究表明,在不降低膜的原始通量条件下,PSt-b-P(A-mPEG)改性PES超滤膜具有良好的抗牛血清蛋白(BSA)污染的能力,改性膜比未改性膜显示出较大的通量恢复率. 相似文献
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Nady N Schroën K Franssen MC Lagen Bv Murali S Boom RM Mohyeldin MS Zuilhof H 《ACS applied materials & interfaces》2011,3(3):801-810
Poly(ethersulfone) (PES) membranes are widely used in industry for separation and purification purposes. However, the drawback of this type of membranes is fouling by proteins. For that reason, modification of PES membranes has been studied to enhance their protein repellence. This paper presents the first example of enzyme-catalyzed modification of PES membranes. Various phenolic acids (enzyme substrates) were bound to a membrane under very mild conditions (room temperature, water, nearly neutral pH) using only laccase from Trametes versicolor as catalyst. The extent of modification, monitored, for example, by the coloration of the modified membranes, can be tuned by adjusting the reaction conditions. The most significant results were obtained with 4-hydroxybenzoic acid and gallic acid as substrates. The presence of a covalently bound layer of 4-hydroxybenzoic acid on the grafted membranes was confirmed by X-ray photoelectron spectroscopy (XPS), infrared reflection absorption spectroscopy (IRRAS), and NMR. In the case of gallic acid, PES membrane modification is mainly caused by adsorption of enzymatically formed homopolymer. The ionization potential of the substrates, and the electronic energies and spin densities of the radicals that are intermediates in the attachment reaction were calculated (B3LYP/6-311G(d,p)) to determine the reactive sites and the order of reactivity of radical substrates to couple with the PES membrane. The calculated order of reactivity of the substrates is in line with the experimental observations. The calculated spin densities in the phenolic radicals are highest at the oxygen atom, which is in line with the formation of ether linkages as observed by IRRAS. The liquid fluxes of the modified membranes are hardly influenced by the grafted layers, in spite of the presence of a substantial and stable new layer, which opens a range of application possibilities for these modified membranes. 相似文献
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De Bartolo L Morelli S Rende M Salerno S Giorno L Lopez LC Favia P d'Agostino R Drioli E 《Journal of nanoscience and nanotechnology》2006,6(8):2344-2353
New strategies aimed to surface modification of polymeric membranes are crucial to optimise cell-biomaterial interactions in vivo and in vitro biohybrid systems. In this paper, we investigated the surface modification of Polyethersulfone (PES) membranes by plasma polymerisation of acrylic acid monomers (PES-pdAA) and by immobilization of galactonic acid through a hydrophilic "spacer arm" molecule (PES-pdAA-SA-GAL). The modification steps were characterised by high resolution X-ray photoelectron spectroscopy. The performance of modified and unmodified membranes was evaluated by assessing the expression of liver specific biotransformation functions of pig and human hepatocytes. Human liver cells cultured on PES-pdAA-SA-GAL membranes displayed an enhanced albumin production, urea synthesis and protein secretion for 24 days of culture. The immobilisation of galactose derivative units on the membrane allowed specific interactions with hepatocytes biomimicking the cellular microenvironment and produced an improvement of the long-term maintenance and differentiation of human hepatocytes. 相似文献
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This paper reports the performance of two different artificial neural networks (ANN), Multi Layer Perceptron (MLP) and Radial Basis Function (RBF) compared to conventional software for prediction of the pore size of the asymmetric polyethersulfone (PES) ultrafiltration membranes. ANN has advantages such as incredible approximation, generalization and good learning ability. The MLP are well suited for multiple inputs and multiple outputs while RBF are powerful techniques for interpolation in multidimensional space. Three experimental data sets were used to train the ANN using polyethylene glycol (PEG) of different molecular weights as additives namely as PEG 200, PEG 400 and PEG 600. The values of the pore size can be determined manually from the graph and solve it using mathematical equation. However, the mathematical solution used to determine the pore size and pore size distribution involve complicated equations and tedious. Thus, in this study, MLP and RBF are applied as an alternative method to estimate the pore size of polyethersulfone (PES) ultrafiltration membranes. The raw data needed for the training are solute separation and solute diameter. Values of solute separation were obtained from the ultrafiltration experiments and solute diameters ware calculated using mathematical equation. With the development of this ANN model, the process to estimate membrane pore size could be made easier and faster compared to mathematical solutions. 相似文献
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聚偏氯乙烯超滤膜的辐照接枝改性研究 总被引:22,自引:8,他引:14
聚偏氟乙烯超滤膜经Co-60辐照,接枝乙烯基单体,再经磺化,成为磺化聚氟乙烯超滤膜。研究了辐照剂量、接枝时间对接枝率的影响和磺化反应的条件等。试验表明,改性后膜的亲水性和抗污染性增强。此外,还讨论了膜改性的机理。 相似文献
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