Monitoring Flocculation in Situ in Sterically Stabilized Silica Dispersions Using Rheological Techniques

Grover, Gautam Singh; Bike, Stacy G.

doi:10.1021/la00005a060

Cited by 12 publications

(4 citation statements)

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“…The rheology of dispersions of sterically stabilized particles has been studied intensively, − and basic colloidal parameters have been deduced from these data. Of interest in quantifying the stabilizing effect of the polymer layer is the interaction potential V .…”

Section: Introductionmentioning

confidence: 99%

Electrosteric Stabilization of Colloidal Dispersions

et al. 2002

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The electrosteric stabilization of model colloidal dispersions is quantified through high-frequency rheometry and complementary techniques. Model aqueous dispersions with a poly(butyl acrylate)polystyrene core and a layer of poly(methacrylic acid) grafted onto the surface are prepared and characterized. The influence of pH, electrolyte concentration, and amount of polymer in the stabilizing layer on dispersion stability and rheology is investigated. Dynamic light scattering, electrophoretic mobility, and rheology are used to quantify thickness, hydrodynamic permeability, and charge density of the stabilizing shell. A collapsed layer at low pH leads to aggregation after addition of salt, while a swollen layer at high pH induces stability. The colloidal interaction potential is deduced from measurements of the high-frequency elastic modulus using torsional resonators. The complex electrosteric forces are shown to be dominated by the excess osmotic pressure created by overlap of the electrosteric layer for particles in contact. The measured moduli G′ ∞ can be predicted quantitatively based on a simple model for the osmotic repulsion introduced by Vincent et al. [J.

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Section: Introductionmentioning

confidence: 99%

Electrosteric Stabilization of Colloidal Dispersions

et al. 2002

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“…The electrostatic and hydrophobic interactions of linear-type macro-ions with other macro-ions and/or small molecules have been studied in detail by many researchers including our group, for example (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). Several researchers have clarified the electrostatic and nonelectrostatic interactions of colloidal spheres with polyelectrolytes (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22).…”

Section: Introductionmentioning

confidence: 99%

Absorption of Polyelectrolytes on Colloidal Surfaces as Studied by Electrophoretic and Dynamic Light-Scattering Techniques

Okubo

Suda

1999

Journal of Colloid and Interface Science

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“…Attractive and repulsive forces between colloids are triggered by adjusting pH, adjusting ionic strength, adding macromolecules to the dispersion medium [5], or directly modifying the surface of the colloidal particles [9]. In recent studies, colloids were modified through adsorption of lipids [10], proteins [11], surfactants [12], or polymers [13,14] onto the particle surface. Chemical functionalization was done via grafted polymer chains [9] or with the help of silanization of colloids [15].…”

Section: Introductionmentioning

confidence: 99%

Systematic modification of the rheological properties of colloidal suspensions with polyelectrolyte multilayers

et al. 2011

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Tailoring rheological properties of colloidal suspensions with the adsorption of polyelectrolyte multilayers (PEMs) is based on the idea of controlling macroscopic mechanical properties by modifying the particle surface in a reproducible and well-understood manner. With layer-by-layer self-assembly, monodisperse polystyrene particles are coated with up to ten layers of the oppositely charged strong polyelectrolytes: poly(diallyl dimethyl ammonium chloride) and poly(styrene sulfonate). The conformation of the adsorbed polyelectrolyte is controlled by the ionic strength of the used aqueous polyelectrolyte solution. For 1M NaCl solution, a brushlike adsorption of the polyelectrolyte is expected. The ability of PEMs to serve on a nanoscale level as surface modifiers and influence macroscopic rheological properties like viscoelasticity, yield stress, and shear banding is discussed. The mechanical behavior of these suspensions is qualitatively described by the theory of Derjaguin-Landau-Verwey-Overbeek with short-range repulsion and long-range attraction. A scaling rule is proposed which distinguishes between the precusor and the multilayer regime.

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Monitoring Flocculation in Situ in Sterically Stabilized Silica Dispersions Using Rheological Techniques

Cited by 12 publications

References 0 publications

Electrosteric Stabilization of Colloidal Dispersions

Electrosteric Stabilization of Colloidal Dispersions

Absorption of Polyelectrolytes on Colloidal Surfaces as Studied by Electrophoretic and Dynamic Light-Scattering Techniques

Systematic modification of the rheological properties of colloidal suspensions with polyelectrolyte multilayers

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