氧化石墨烯/聚偏氟乙烯复合膜的制备及抗污染性能
Modification of polyvinylidene fluoride composite membrane by graphene oxide and its antifouling properties
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摘要: 采用改进的Hummers法制备出具有"二维结构"的氧化石墨烯（graphene oxide，GO），以聚偏氟乙烯（PVDF）为高分子聚合物，聚乙烯吡咯烷酮（PVP）为制孔剂，采用浸没沉淀相转化法制备得到GO/PVP/PVDF复合超滤膜。测定了复合超滤膜的纯水通量、接触角、污染物截留、膜片SEM和AFM图像、膜面Zeta电位以及复合膜与牛血清蛋白（BSA）之间的微观作用力等参数。结果表明，随着GO含量的增加，膜表面亲水性官能团的含量显著增加，复合膜的接触角从74.61°（M0）减小到66.39°（M2），纯水通量增加了33%；SEM和AFM的结果表明，复合膜的膜孔有所拓宽，表面粗糙度由23.79（M0）降低为20.2（M3），表面更加平滑。而GO的加入使得复合膜与BSA之间的微观作用力也从2.47 mN·m-1降至0.13 mN·m-1，说明GO/PVP/PVDF复合超滤膜较传统PVDF超滤膜具有较优越的抗污染性能。
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关键词:
- 氧化石墨烯 /
- 聚偏氟乙烯(PVDF) /
- 复合超滤膜 /
- 微观作用力 /
- 膜污染
Abstract: The graphene oxide (GO) with two-dimensional structure was prepared through a modified Hummers' method.GO/PVP/PVDF composite ulrrafiltration(UF) membrane were prepared with polyvinylidene fluoride(PVDF),polyvinylpyrrolidone(PVP) and GO by general phase inversion method.The pure water flux,contact angle,pollutant rejection,SEM and AFM images,Zeta potential and interaction force between composite membrane and BSA were measured.Results show that with the increase of GO in the composite membrane,the content of hydrophilic functional groups in the composite membrane surface effectively increased,contact angle decreased from 74.61°(M0) to 66.39°(M2),while pure water flux increased by 33%.The image analyses by scanning electron microscopy (SEM) and atomic force microscopy (AFM) exhibited that the finger-like pores of the GO/PVP/PVDF membrane were broadened and surface roughness reduced from 23.79 (M0) to 20.2 (M3) with a smoother surface.Moreover,with the introducing of GO,the interaction force between composite membrane and BSA changed from 2.47 mN·m-1 to 0.13 mN·m-1.The results testify that GO/PVP/PVDF composite UF membrane has a superior antifouling propensities compared to traditional PVDF UF membrane. -
河流是连接陆海的物质循环通道，其对颗粒物的输移过程是全球沉积循环的重要环节。人类活动改变了沉积物的迁移、输运和封存，如今人类活动已在全球尺度上主导了上述通量过程[1]。我国长江流域的沉积物也呈现出类似的演变特征[2-3]。2006—2017年长江上游和全流域的泥沙输出量相较于1950—1985年平均水平，分别减少了96%和74%。上游大坝建设已成为泥沙减少的主要原因。随着上游梯级大坝体系的建成并运行，导致流域沉积物传输的连通性相应下降，河流水文节律随之改变，河流-湖泊相互作用减弱。不仅如此，沉积物来源正在从上游流域的地表土壤侵蚀向中下游流域河道侵蚀转变，沉积物成分和相关养分负荷均在发生变化[2]。中下游河流河道和河岸侵蚀严重，威胁着长江堤岸的稳定性。以三峡水利枢纽为代表的中上游水库群建设运行后，长江沉积物通量变化引起的中游崩岸、长江口侵蚀等问题需要高度关注。
沉积物通量的变化还将引起碳、磷、硅等生源要素海陆循环的深刻变化(图1)。河流生源要素输送对海洋及流域本身的水生生态系统均具有极为重要的意义。亚马逊河、长江等大河输送的营养物质为河口海区海洋生物以及河流内部的水生生物的繁殖提供了重要营养物质保证[2, 4]。然而，全球闸坝建设会导致河流沉积物通量减少，从而对生源物质循环造成深刻影响[5]。同样以长江为例，2003年，以三峡水利枢纽为核心的上游干支流水库群运行以后，长江中下游的总磷和颗粒态磷通量分别减少了77%和75%[6]。上游水库拦截了大约50×103～100×103 t·a−1的潜在生物有效磷[6]，其潜在环境效应超过了当前人类活动注入磷的数量。上游水库磷累积增加了水域富营养化潜势，成为潜在的污染源，而这本应该成为长江河口及近岸海域的生物营养资源。由此可以看出，由于河流闸坝建设及河运等人类活动所带来的全球沉积循环的变化，将对生源要素的陆海生物地球化学产生深刻影响，其中，大河流域沉积物通量减少，以及伴随的生源要素的减少，其长期环境效应必须引起学者们的重视。
长江经济带横跨中国东中西三大地理区域，是具有全球影响力的内河经济带、东中西互动合作的协调发展带、沿海沿江沿边全面推进的对内对外开放带，也是生态文明建设的先行示范带。2016年1月5日，习近平总书记在推动长江经济带发展座谈会上强调，共抓大保护、不搞大开发，努力把长江经济带建设成为生态更优美、交通更顺畅、经济更协调、市场更统一、机制更科学的黄金经济带，探索出一条生态优先、绿色发展新路子。经过各方共同努力，目前，长江经济带生态环境总体改善、经济发展向好。但同时也应该看到，由于长江流域水沙新态势的形成，长江流域物质基础边界发生了新的变化，这种变化必须在长江生态环境修复和保护工作中予以足够的考虑。正如SYVITSKI Jaia 在论文中所提议，在学界发起地球沉积循环重大挑战性问题（“Earth Sediment Cycle Grand Challenge”）研究计划，开展生物地球物理-工程-社会耦合的多维度分析，以期为与之相关人类活动的规划和工程提供参考与指导。为此，希望我国学术界针对长江流域人类世沉积循环新的特征，结合长江流域详实的监测数据进行分析和研判，全面认识和把握长江水资源及其高度关联的水环境、水生态重大问题，形成长江水资源保护与开发的系统观点看法和对策建议，从而为长江经济带战略提供科技支撑。
原文作者
SYVITSKI Jaia, 国际著名沉积学家、美国科罗拉多大学教授。研究领域为沉积物输送、海陆相互作用和地球表面动力学。她曾担任地表动力学模拟系统研究群体(Community Surface Dynamics Modeling System，CSDMS)执行主任，领导68个国家科学家开发、支持和应用综合计算机模型；主持了国际科学协会理事会(International Council for Science，ICSU)的国际地圈生物圈计划（2011—2016年）。2009年获得加拿大皇家学会亨斯迈奖章，2016年获得SEPM Francis Shepard奖章。E-mail：jai.syvitski@colorado.edu。
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[1] CHAKRABARTY B,GHOSHAL A K,PURKAIT M K. Ultrafiltration of stable oil-in-water emulsion by polysulfone membrane[J].Journal of Membrane Science,2008,325(1):427-437 [2] BRZOZOWSKA A M,KEUZER A D,DETREMBLEUR C,et al.Grafted ionomer complexes and their effect on protein adsorption on silica and polysulfone surfaces[J].Colloid Polymer Science,2010,288(16):1621-1632 [3] MAGNENET C,JURIN F E,LAKARD S,et al.Polyelectrolyte modification of ultrafiltration membrane for removal of copper ions[J].Colloids and Surfaces A:Physicochemical and Engineering Aspects,2013,435:170-177 [4] WANG K Y,CHUNG T S, GRYTA M.Hydrophobic PVDF hollow fiber membranes with narrow pore size distribution and ultra-thin skin for the fresh water production through membrane distillation[J].Chemical Engineering Science,2008,63(9):2587-2594 [5] LIU F,HASHIM N A,LIU Y T,et al.Progress in the production and modification of PVDF membranes[J].Fuel and Energy Abstracts,2011,375(1):1-27 [6] ZHANG S,WANG R,ZHANG S,et al.Development of phosphorylated silica nanotubes (PSNTs)/poly(vinylidene fluoride)(PVDF)composite membranes forwastewater treatment[J].Chemical Engineering Journal,2013,230(1):260-271 [7] CUI A H,LIU Z,XIAO C F,et al.Effect of micro-sized SiO2-particle on the performance of PVDF blend membranes via TIPS[J].Journal of Membrane Science,2010,360(1/2):259-264 [8] MA W Z,CAO Y Y,GONG F H,et al.Poly(vinylidene fluoride) membranes prepared via nonsolvent induced phase separation combined with the gelation[J].Colloids and Surfaces A:Physicochemical and Engineering Aspects,2015,479:25-34 [9] HUANG S R,WU G Z,CHEN S M.Preparation of microporous poly(vinylidene fluoride)membranes via phase inversion in supercritical CO2[J]. Journal of Membrane Science,2007,293(1/2):100-110 [10] CHANACHAI A,MEKSUP K,JIRARATANANON R.Coating of hydrophobic hollow fiber PVDFmembrane with chitosan for protection against wetting and flavor loss in osmotic distillation process[J].Separation and Purification Technology,2010,72(2):217-224 [11] LOUIE J S,PINNAU I,CIOBANU I,et al.Effects of polyether-polyamide block copolymer coating on performance and fouling of reverse osmosis membranes[J].Journal of Membrane Science,2006,280(1/2):762-770 [12] JU J P,WANG T M,WANG Q H.Superhydrophilic and underwater superoleophobic PVDF membranes via plasma-induced surface PEGDA for effective separation of oil-in-water emulsions[J].Colloids and Surfaces A:Physicochemical and Engineering Aspects,2015,481:151-157 [13] KIM E S,KIM Y J,YU Q,et al.Preparation and characterization of polyamide thin-film composite (TFC) membranes on plasma-modified polyvinylidene fluoride(PVDF)[J].Journal of Membrane Science,2009,344(1/2):71-81 [14] WANG L,PAN K,LI L,et al.Surface hydrophilicity and structure of hydrophilic modified PVDF membrane by nonsolvent induced phase separation and their effect on oil/water separation performance[J].Industrial & Engineering Chemistry Research,2014,53(15):6401-6408 [15] YAN L,LI Y S,XIANG C B,et al.Effect of nano-sized Al2O3-particle addition on PVDF ultrafiltration membrane performance[J].Journal of Membrane Science,2006,276(1):162-167 [16] YAN L,LI Y S,XIANG C B.Preparation of poly(vinylidene fluoride)(PVDF)ultrafiltration membrane modified by nano-sized alumina(Al2O3)and its antifouling research[J].Polymer,2005,46(18):7701-7706 [17] ISTRATE O M,PATON K R,KHAN U,et al.Reinforcement in melt-processed polymer-graphene composites at extremely low graphene loading level[J].Carbon,2014,78(18):243-249 [18] JIN J,RAFIQ R,GILL Y Q,et al.Preparation and characterization of high performance of graphene/nylon nanocomposites[J].European Polymer Journal,2013,49(9):2617-2626 [19] BARROSO-BUJANS F,CERVENY S,ALEGRIA A,et al.Sorption and desorption behavior of water and organic solvents from graphite oxide[J].Carbon,2010,48(11):3277-3286 [20] FANG Q L,CHEN B L.Self-assembly of graphene oxide aerogels by layered double hydroxides cross-linking and their application in water purification[J].Journal of Materials Chemistry,2014,2(23):8941-8951 [21] DONG Z H,WANG D,LIU X,et al.Bio-inspired surface-functionalization of graphene oxide for the adsorption of organic dyes and heavy metal ions with a super high capacity[J].Journal of Materials Chemistry,2014,2(14):5034-5040 [22] RAMESHA G K,KUMARA A V,MURALIDHARA H B,et al.Graphene and graphene oxide as effective adsorbents toward anionic and cationic dyes[J].Journal of Colloid and Interface Science,2011,361(1):270-277 [23] WANG Z H,YU H R,XIA J F,et al.Novel GO-blended PVDF ultrafiltration membranes[J].Desalination,2012,299(8):50-54 [24] SAFARPOUR M,KHATAEE A,VATANPOUR V.Preparation of a novel polyvinylidene fluoride(PVDF)ultrafiltration membrane modified with reduced graphene oxide/titanium dioxide(TiO2) nanocomposite with enhanced hydrophilicity and antifouling properties[J].Industrial & Engineering Chemistry Research,2014,53(34):13370-13382 [25] WANG N X,JI S L,LI J,et al.Poly(vinyl alcohol)-graphene oxide nanohybrid pore filling membrane for pervaporation of toluene/n-heptane mixtures[J].Journal of Membrane Science,2014,455:113-120 [26] YU L Y,XU Z L,SHEN H M,et al.Preparation and characterization of PVDF-SiO2 composite hollow fiber UF membrane by sol-gel method[J].Journal of Membrane Science,2009,337(1/2):257-265 [27] GANESH B M, ISLOOR A M, ISMAIL A F. Enhanced hydrophilicity and salt rejection study of graphene oxide-polysulfone mixed matrix membrane[J]. Desalination, 2013, 313(7):199-207 [28] ONG C S,LAU W J,GOH P S,et al.Preparation and characterization of PVDF-PVP-TiO2 composites hollow fiber membranes for oily wastewater treatment using submerged membrane system[J].Desalination and Water Treatment,2015,53(5):1213-1223 [29] 张佳利.化学还原氧化石墨烯及其衍生物的制备、性质和应用研究[D].上海:上海交通大学,2011 [30] HUMMERS W S,OFFEMAN R E.Preparation of graphitic oxide[J].Journal of the American Chemical Society,1958,80(6):1339 [31] WANG G X, YANG J, PARK J, et al. Facile synthesis and characterization of graphene nanosheets[J]. Journal of Physical Chemistry C,2008, 112(22):8192-8195 [32] SAFARPOUR M,KHATAEE A,VATANPOUR V.Effect of reduced graphene/TiO2 nanocomposite with different molar ratios on the performance of PVDF ultrafiltration membranes[J]. Separation and Purification Technology, 2015, 140:32-42 [33] ZINADINI S, ZINATIZADEH A A, RAHIMI M, et al. Preparation of a novel antifouling mixed matrix PES membrane by embedding graphene oxide nanoplates[J]. Journal of Membrane Science, 2014, 453(3):292-301 [34] WANG X,LIU Z,YE X,et al.A facile one-pot method to two kinds of graphene oxide-based hydrogels with broad-spectrum antimicrobial properties[J].Chemical Engineering Journal,2015,260:331-337 [35] YE N,XIE Y,SHI P,et al.Sythesis of magnetite/graphene oxide/chitosan composite and its application for protein adsorption[J].Materials Science and Engineering C,2014,45:8-14 [36] BUTT H J, CAPPELLA B,KAPPL M.Force measurements with the atomic force microscope:Technique,interpretation and applications[J].Surface Science Reports,2005,59(1):1-152 [37] LI Q, ELIMELECH M.Organic fouling and chemical cleaning of nanofiltration membranes:Measurements and mechanisms[J].Environmental Science and Technology,2004,38(17):4683-4693 [38] COSTA A R,DEPINHO M N D, ELIMELECH M. Mechanisms of colloidal natural organic matter fouling in ultrafiltration[J].Journal of Membrane Science, 2006,281(1/2):716-725 [39] YAMAMURA H, KIMURA K, OKAJIMA T, et al. Affinity of functional groups for membrane surfaces:Implications for physically irreversible fouling[J].Environmental Science and Technology,2008,42(14):5310-5315 [40] LEE S,ELIMELECH M.Relating organic fouling of reverse osmosis membranes to intermolecular adhesion forces[J].Environmental Science and Technology,2006,40(3):980-987 -
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