Polymer/Surfactant Mixture Activity at theCyclohexane/Water Interface and the RemovalofSurfactantbyGrapheneOxideNanoparticles

Abstract

Thisthesisinvestigatesmeasurementsofinterfacialtensionofpolymer/surfactantmixturesat oil-water interface and removal of (BAC, cationic surfactant) from water using grapheneoxidenanoparticles. In this thesis, we have studied the adsorption of Sodium polystyrene sulfonate, (NaPSS,anionicpolyelectrolyte)/BenzyldimethylhexadecylammoniumChloride(BAC,cationicsurfactant),Polyallylaminehydrochloride(PAACl,cationicpolyelectrolyte)/sodiumdodecylbenzene sulfonate (SDBS, anionic surfactant) and Polyvinyl alcohol (PVA, neutral watersolublepolymer)/sodiumdodecylbenzenesulfonate(SDBS)attheCyclohexane-waterinterface. Individual polyelectrolytes NaPSS and PAACl are interfacial inactive. PolyvinylAlcohol shows interfacial activity comparable to surface active agents due to its H-bondingforming capacity. For the system SDBS/PAACl, a hump in the interfacial tension wasobservedwithmaximaintheinterfacialtension.Thisisexplainedbychangesoftheamountofdifferentpolyelectrolyte/surfactantcomplexstructuresattheinterfaceandtheircompetitionwithcomplexesinthebulk.Nohumpnormaximaintheinterfacialtension wasobserved for the system BAC/NaPSS but surprisingly an increase in the interfacial tensionwas observed. This increase is due to insufficient BAC molecules to neutralize the chargesat the repeating units of NaPSS. To the best of our knowledge the finding here for theoppositelychargepolymer/surfactantsystemsstudiedatthecyclohexaneinterfacearereportedfor thefirst time. Graphene oxide nanoparticles were prepared and used to remove cationic surfactantBAC,grapheneoxidegiveshighefficiencyintheremovalofcationicsurfactantfromwater,wheretheunremovedamountofBACsurfactantafteradsorptionprocesswasdeterminedby

spectrophotometricstudyaftercomplexationwithoppositelychargedsyntheticdye(Indigocarmine).