The Structure-Function Relationship of PAMAM Dendrimers as Robust Oil Dispersants

文档简介PAMAMdendrimershaverecentlybeeninvestigatedasefficientandbiocompatibleoil11dispersantsutilizingtheirencapsulationcapacity;however,theirhighcationicchargedensityhas12beenshowntobecytotoxic.Itisthereforeimperativetomitigatecationiccharge-induced13toxicityandunderstandtheeffectsofsuchchanges.Presentedhereisasynergisticexperimental14andcomputationalapproachtoexaminetheeffectsofvaryingterminalsurfacechargeonthe15capacityofdendrimerstodispersemodelliner,polycyclicaromatic,andhybridhydrocarbons.16Unchargeddendrimerscollapsebyformingintra-molecularhydrogenbonds,whichreducethe17hostingcapability.Ontheotherhand,changingthesurfacechargesfrompositivetonegative18greatlyshiftsthepKaoftertiaryaminesofthePAMAMdendrimerinterior.Asaresult,the19negativelychargeddendrimershaveasignificantpercentageoftertiaryaminesprotonated,20~30%.Thisunexpectedchangeininteriorprotonationstatecauseelectrostaticinteractionswith21theanionicterminalgroups,leadingtocontractionandamarkeddecreaseinhydrocarbon22hostingcapacity.Thepresentworkhighlightstherobustnatureofdendrimeroildispersionandalsoilluminatespotentiallyunintendedorunanticipatedeffects23ofvaryingdendrimersurface24chemistryontheirencapsulationorhostingefficacy,whichisimportantfortheirenvironmental,25industrial,andbiomedicalapplications.