salt-polymer interaction in concentrated salt dispersion

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Salt-Polymer Interaction in Concentrated Salt Dispersion. XIAOHUA FANG Columbia University. Center for Particulate & Surfactant Systems (CPaSS) IAB Meeting New York, NY August 20th, 2009. H 2 O. CO 3 2-. Na +. Step III: Understand 3-component systems. - PowerPoint PPT Presentation

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  • Salt-Polymer Interaction in Concentrated Salt Dispersion Center for Particulate & Surfactant Systems (CPaSS)IAB Meeting New York, NYAugust 20th, 2009XIAOHUA FANGColumbia University

  • Possible Interactions in a Dispersion System

  • IntroductionChallenges in real formulations containing high salt concentration.Homogenous or dispersed Stable with time or temperaturePourablein a wide range of temperatureLow salt concentration rangecharge screened; polymer collapsed, etc.Ultra-High salt concentration, morphology of polymer chain and its function?The interaction of polyelectrolyte and salt Coil-Collapse-Re-expansion

  • Materials/Methods*Salt-Polymer InteractionsDensityLight ScatteringConductivityRheometryMaterialsMethods*Sodium carbonate(Soda Ash) *Polyacrylic acid *Water * Other additives*Water related InteractionsWater Activity

  • Radius of Gyration in concentrated salt solutionRg grows exponentially with salt level increase in entanglement Concentration

  • Hydrodynamic Radius in salt solutionAt higher salt level, PAA molecules oscillate within a larger effective region.RH increases with polymer concentration after a certain threshold PAA level.

  • Ion Condensation on PolymersIon condensation happens and the salt species condensed onto PAA chains.

    Larger molecules are more effective in holding salts than smaller chains.

  • Low MwHigh MwSpeculation---Concentration DependenceNo SaltHigh Salt

  • Higher Salt Level More Rheological Sensitivity to PAA ConcentrationViscosity increases with PAA concentration at all salt levels.At high salt level, the increase in viscosity with PAA concentrationis more significant.

  • Higher Salt Level More Rheological Sensitivity to TemperatureViscosity decreases with temperature at all salt levels.At high salt level, the decrement in viscosity with temperatureis more significant.

  • Small MoleculeLarge MoleculeSchematic Diagram of Salt Ions LocalizationLow TemperatureHigh Temperature

  • Concluding Remarks1.is unfolded and more hydrated. 2.plays a more dominant role on the rheologicalbehavior of the system.3.holds more salt locally. As salt level increases, PAALarger molecules are more efficient in holding ions locally.

  • Future PlansConduct light scattering, rheological, conductivity measurements on multi-component system.

    2.Elucidate the overall mechanism by which dispersion and flow properties are controlled in the system.NSF-Industry/University Cooperative Research Center All the Industrial CollaboratorsWe owe great thanks to:

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