分子量和化学性质对NOM光谱的的影响

分子量和化学性质对NOM光谱的的影响EffectsofMolecularWeightDistributionandChemicalPropertiesofNaturalOrganicMatteronGoldNanoparticleAggregationStaceyM.Louie,†,‡RobertD.Tilton,†,§,⊥andGregoryV.Lowry*,†,‡,§†CenterfortheEnvironmentalImplicationsofNanoTechnology(CEINT),‡DepartmentofCivilandEnvironmentalEngineering,§DepartmentofChemicalEngineering,and⊥DepartmentofBiomedicalEngineering,CarnegieMellonUniversity,Pittsburgh,Pennsylvania15213,UnitedStates*SSupportingInformationABSTRACT:Thecomplexityofnaturalorganicmatter(NOM)motivatesdeterminationofhowspecificcomponentsinaNOMmixtureinteractwithandaffectnanoparticle(NP)behavior.TheeffectsoftwoSuwanneeRiverNOMfractions(separatedbya100,000g/molultrafiltrationmembrane)ongoldNPaggregationarecompared.Theweight-averagemolecularweight,Mw,fortheunfractionatedNOMwas23,300g/mol,determinedbysizeexclusionchromatographywithmultianglelightscattering.TheNOMwascomprisedof∼1.8wt%of>100,000g/molretentate(NOMr,Mw=691,000g/mol)and98wt%offiltrate(NOMf,Mw=12,800g/mol).TenppmofNOMrprov