Interfacial polymerization of thin film nanocomposites: A new concept for reverse osmosis membranes

文档简介作者：AlbertoTiraferria,KaiLoonChenb,RajandreaSethia,MenachemElimelechb　　（aDITAGDipartimentodiIngegneriadelTerritorio,dell’AmbienteedelleGeotecnologie,PolitecnicodiTorino,CorsoDucadegliAbruzzi,24,10129,Torino,Italy　　bDepartmentofChemicalEngineering,EnvironmentalEngineeringProgram,YaleUniversity,NewHaven,CT06520-8286,USA）　　摘要：Injectionofnanoscalezero-valentiron（NZVI）ispotentiallyapromisingtechnologyforremediationofcontaminatedgroundwaters.However,theefficiencyofthisprocessissignificantlyhinderedbytherapidaggregationoftheironnanoparticles.Theaimofthisstudywastoenhancethecolloidalstabilityofthenanoparticlesthroughtheadditionofthe“green”polymerguargum.Weevaluatedthepropertiesofguargumanditsinfluenceonthesurfaceproperties,particlesize,aggregation,andsedimentationofironnanoparticles.Commercialironnanoparticlesweredispersedinguargumsolutions,andtheiraggregationandsedimentationbehaviorswerecomparedtothoseofbareironnanoparticlesandcommercialnanoparticlesmodifiedwithabiodegradablepolymer（polyaspartate）.Highperformancesizeexclusionchromatography,chargetitration,andviscosityassessmentshowedthatguargumisahighmolecularweightpolymerwhichisnearlyneutrallycharged,renderingitsuitableforstericstabilizationoftheironnanoparticles.Electrophoreticmobilitymeasurementsdemonstratedtheabilityofguargumtoadsorbonthenanoparticles,formingaslightlynegativelychargedlayer.Dynamiclightscatteringexperimentswereconductedtoestimatetheparticlesizeofthedifferentnanoparticlesuspensionsandtodeterminetheaggregationbehavioratdifferentionicstrengths.Guargumeffectivelyreducedthehydrodynamicradiusofthebarenanoparticlesfrom500nmtolessthan200nmandpreventedaggregationofthenanoparticlesevenatveryhighsaltconcentrations（0.5MNaCland3mMCaCl2）.Sedimentationprofilesofthedifferentnanoparticlesuspensionsconfirmedtheimprovedstabilityoftheironnanoparticlesinthepresenceofguargum.Theresultsstronglysuggestthatguargumcanbeusedtoeffectivelydeliverstabilizedzero-valentironnanoparticlesforremediationofcontaminatedgroundwateraquifers.　　关键词：Zero-valentironnanoparticles;Guargum;Greenpolymers;Aggregation;Stericstabilization;Groundwaterremediation;DLS;Particlesize