Adsorption-of-polar--nonpolar--and-substituted-aromatics-to-colloidal-graphene-oxide-nanoparticles

Adsorptionofpolar,nonpolar,andsubstitutedaromaticstocolloidalgrapheneoxidenanoparticlesFangWanga,JorisJ.-H.Haftkab,TheoL.Sinnigeb,JoopL.M.Hermensb,*,WeiChena,*aCollegeofEnvironmentalScienceandEngineering,MinistryofEducationKeyLaboratoryofPollutionProcessesandEnvironmentalCriteria,TianjinKeyLaboratoryofEnvironmentalRemediationandPollutionControl,NankaiUniversity,WeiJinRoad94,Tianjin300071,ChinabInstituteforRiskAssessmentSciences(IRAS),UtrechtUniversity,Yalelaan104,P.O.Box80177,3508TDUtrecht,TheNetherlandsarticleinfoArticlehistory:Received26October2013Receivedinrevisedform10December2013Accepted13December2013Keywords:GrapheneoxidenanoparticlesAdsorptionPolarcompoundsAromaticsabstractWeconductedbatchadsorptionexperimentstounderstandtheadsorptivepropertiesofcolloidalgra-pheneoxidenanoparticles(GONPs)forarangeofenvironmentallyrelevantaromaticsandsubstitutedaromatics,includingmodelnonpolarcompounds(pyrene,phenanthrene,naphthalene,and1,3-dichlorobenzene)andmodelpolarcompounds(1-naphthol,1-naphthylamine,2,4-dichlorophenol,and2,4-dinitrotoluene).GONPsexhibitedstrongadsorptionaffinitiesforallthetestcompounds,withdis-tributioncoefficientsontheorderof103e106L/kg.AdsorptiontoGONPsismuchmorelinearthantocarbonnanotubes(CNTs)andC60,likelybecauseGOnanoflakesareessentiallyindividuallydispersed(renderingadsorptionsitesofsimilaradsorptionenergy)whereasCNT/C60arepronetobundling/ag-gregation.ForagivencompoundGONPsandCNTsoftenexhibitdifferentadsorptionaffinities,whichisattributabletothedifferencesinboththemorphologyandsurfacechemistrybetweenthetwonano-materials.Particularly,thehighsurfaceO-contentofGONPsenablesstrongH-bondingandLewisacidebaseinteractionswithhydroxyl-andamino-substitutedaromatics.�2013ElsevierLtd.Allrightsreserved.1.IntroductionGrapheneoxide(GO)isanewclassofcarbonaceousnano-materialthathasshowngreatpromisesinanumberofapplica-tions,suchasenergy-relatedmaterials,sensors,biomedicines,tomentionafew(Chenetal.,2012).TherapidlyincreasingproductionanduseofGOwilleventuallycauseitsre