A series of progress in PVDF oil-water separation membrane materials made by Ningbo Institute of materials, Chinese Academy of Sciences

With the rapid development of China's economy, a large number of oil-bearing sewage is discharged At the same time, the frequent occurrence of marine oil spills has posed a serious threat to the ecological environment and human health The traditional oil-water separation methods mainly include air flotation, centrifugal separation, adsorption and combustion, but they all have the disadvantages of low efficiency, high cost and narrow application range Because of the advantages of good structure controllability, high separation efficiency and high separation accuracy, ultra wet separation membrane has become a research hotspot in the field of oil-water separation Recently, Liu Fu, a researcher of Ningbo Institute of materials technology and engineering, Chinese Academy of Sciences, has made a series of new achievements in the direction of high-performance PVDF oil-water separation membrane 1) PVDF instantaneous catalysis and oil water separation membrane To solve the problem of oil-water separation in complex system, pvdf-aunps micro reactor separation membrane with micro nano multi-stage assembly structure was prepared by using PVDF with excellent mechanical properties and thermal stability as the base membrane Firstly, polydopamine was used as the "functional coating" on the membrane surface to modify the PVDF basement membrane, and then the AuNPs microspheres were loaded into the finger pores of PVDF by dynamic filtration to form a microreactor The membrane can catalyze the degradation of nitrophenol and separate oil from water This method plays an important role in promoting the application of oil-water separation membrane in the treatment of oil-bearing wastewater Relevant work has been published in the Chemical Engineering Journal (2018, 334, 579), with Wang Jianqiang and Wu Ziyang as co first authors and Liu Fu as corresponding authors Fig 1 preparation process of PVDF finger catalytic reactor Fig 2 oil water separation and catalytic performance of PVDF membrane 2) flexible PVDF oil water separation membrane with super stable and rigid wetted surface In order to solve the problems of unstable micro nano structure on the surface of polymer microporous membrane, which is easy to creep and decay under chemical corrosion and physical damage, the flexible PVDF microporous membrane with rigid interface and rigid interface was prepared by using biomimetic plant root fixed soil model and using the micro nano structure Limited on the surface of microporous PVDF membrane to fix TiO2 nanoparticles The film has excellent stability, which can resist extreme physical damage (hydraulic pressure, finger cleaning, liquid nitrogen quenching sandpaper friction), high temperature and harsh chemical corrosion (strong acid, strong alkali, strong oxidizer sodium hypochlorite), and can continuously and effectively separate the oil containing water emulsion containing surfactant Under the cross flow mode, the continuous separation of oil in water emulsion (flux reaches 1700L? M -2? H -1 and separation efficiency >96%) is achieved by the PVDF membrane prepared by loading super hydrophilic nano TiO 2 particles (as shown in Fig 3) Relevant work has been published in scientific reports (2017, 7, 14099) Associate researcher Xiong Zhu and Lin Haibo are the co first authors, and Liu Fu is the corresponding author After the publication, the article has attracted wide attention of peers This paper is one of the top 100 articles read by scientific reports in 2017 Fig 3 preparation process of ultra wet rigid interface PVDF membrane Fig 4 oil-water separation performance of rigid interface PVDF membrane 3) super flux electrospinning PVDF oil-water separation membrane In addition to the complexity of oil-water waste liquid and the restriction of membrane interface stability, oil-water separation membrane is often limited by its low flux and easy pollution To solve this problem, the team used electrospinning technology to prepare PVDF nanofiber oil-water separation membrane with ultra-high flux by combining electrospinning and electrostatic spraying, which has a unique structure of micron level fiber and nanometer level Microsphere Composite When the membrane was applied to the water-in-water system with high viscosity, the permeability coefficient was as high as 88166 ± 652 L · m - 2 · H - 1 · bar - 1 (separation efficiency > 99%), which was much higher than the reported data It is a new method suitable for industrial production Relevant work has been published in Journal of Materials Chemistry A (Journal of Materials Chemistry A, 2018, 6, 7014-7020) Wu Jindan, Ph.D of Zhejiang University of science and technology, and Ding Yajie, a master's student, are the co first authors of the paper Wang Jianqiang, Professor of Zhejiang University of science and technology, Wang Jiping and Liu Fu are the co correspondents of the work Fig 5 preparation process of ultra-high flux PVDF nanofiber oil-water separation membrane Fig 6 oil-water separation performance of nanofiber PVDF membrane The above series of research work was supported by national key R & D plan (2017yfb0309600), National Natural Science Foundation (5161101025, 51475449, 51703233), youth Promotion Association of Chinese Academy of Sciences (2014258) and Ningbo innovation team (2014b81004).