Determination of the effective charge of individual colloidal particles

Strubbe, Filip; Beunis, Filip; Neyts, Kristiaan

doi:10.1016/j.jcis.2006.04.034

Cited by 48 publications

(45 citation statements)

References 28 publications

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“…Data shown in Fig. 8 are averages over some 120-150 colloid particles of PS4 and PS10 assembled at different splinters of average diameters of (40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50) µm. We also show data for PS2, which does not form a ring.…”

Section: Methodsmentioning

confidence: 99%

Controlled assembly of single colloidal crystals using electro-osmotic micro-pumps

Niu

Oğuz

Müller

et al. 2017

Phys. Chem. Chem. Phys.

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Abstract:We assemble charged colloidal spheres at deliberately chosen locations on a charged unstructured glass substrate utilizing ion exchange based electro-osmotic micro-pumps.Using microscopy, a simple scaling theory and Brownian Dynamics simulations, we systematically explore the control parameters of crystal assembly and the mechanisms through which they depend on the experimental boundary conditions. We demonstrate that crystal quality depends crucially on the assembly distance of the colloids. This is understood as resulting from the competition between inward transport by the electro-osmotic pump flow and the electro-phoretic outward motion of the colloids. Optimized conditions include substrates of low and colloids of large electro-kinetic mobility. Then a sorting of colloids by size is observed in binary mixtures with larger particles assembling closer to the ion exchanger beads. Moreover, mono-sized colloids form defect free single domain crystals which grow outside a colloid-free void with facetted inner crystal boundaries centred on the ion exchange particle. This works remarkably well, even with irregularly formed ion exchange resin splinters.

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Section: Methodsmentioning

confidence: 99%

Controlled assembly of single colloidal crystals using electro-osmotic micro-pumps

Niu

Oğuz

Müller

et al. 2017

Phys. Chem. Chem. Phys.

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“…In dispersions where ζ is smaller than 25 mV, particles tend to agglomerate, while for ζ >30 mV, particles in dispersions tend to repel each other sufficiently strongly to do not agglomerate [27,28]. The determined values of the ζ-potential of the encapsulated PR112 with the BA-MMA and St-BA copolymer latexes are given in Table 5 and range between -39 and -43 mV.…”

Section: Stability and Aging Of The Encapsulated Pr112 Inksmentioning

confidence: 99%

Development of self-curable hybrid pigment inks by miniemulsion polymerization for inkjet printing of cotton fabrics

2016

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“…Thus, while matter can be expected to be strongly charged in water (ε s ∼ 80), an ionizable surface should carry much less charge in a nonpolar medium with ε s ∼ 5. Although electrostatic interactions in apolar media are indeed weak relative to the aqueous phase, [2][3][4][5][6][7] the repulsion is often regarded as negligible 8,9 mainly on the basis of solvation energy arguments. Generally efforts are invested in enhancing repulsions in apolar media by the addition of micelle-forming surfactants that stabilize potentialdetermining ions [2][3][4][5][6][7]9 or by chemical modification of the surface.…”

Section: Introductionmentioning

confidence: 99%

“…Although electrostatic interactions in apolar media are indeed weak relative to the aqueous phase, [2][3][4][5][6][7] the repulsion is often regarded as negligible 8,9 mainly on the basis of solvation energy arguments. Generally efforts are invested in enhancing repulsions in apolar media by the addition of micelle-forming surfactants that stabilize potentialdetermining ions [2][3][4][5][6][7]9 or by chemical modification of the surface. 3,4,9 Electrostatic interactions in nonpolar media have been exploited in model systems for atomic crystals 10,11 in a) G. Kokot and M. I. Bespalova contributed equally to this work.…”

Section: Introductionmentioning

confidence: 99%

Measured electrical charge of SiO2 in polar and nonpolar media

Kokot

Bespalova

Krishnan

2016

The Journal of Chemical Physics

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We present measurements of the net electrical surface charge of silicon dioxide (SiO2) in contact with solvents of dielectric constants between 5 and 80. Our experimental approach relies on observing the thermal motion of single silica particles confined in an electrostatic fluidic trap created by SiO2 surfaces. We compare the experimentally measured functional form of the trapping potential with that from free energy calculations and thereby determine the net surface charge in the system. Our findings clearly demonstrate that contrary to popular perception, even in the absence of surfactants, the net electrical charge of ionizable surfaces in contact with apolar solvents can be large enough to lead to significant repulsive forces. A charge regulation model for SiO2 surfaces with a single tunable parameter explains our measurements. This model may find general applicability in estimating the net charge of ionizable surfaces, given system parameters such as the dissociation or association constants of the ionizable groups and the pH, ionic strength, and dielectric constant of the solvent phase. We present measurements of the net electrical surface charge of silicon dioxide (SiO 2 ) in contact with solvents of dielectric constants between 5 and 80. Our experimental approach relies on observing the thermal motion of single silica particles confined in an electrostatic fluidic trap created by SiO 2 surfaces. We compare the experimentally measured functional form of the trapping potential with that from free energy calculations and thereby determine the net surface charge in the system. Our findings clearly demonstrate that contrary to popular perception, even in the absence of surfactants, the net electrical charge of ionizable surfaces in contact with apolar solvents can be large enough to lead to significant repulsive forces. A charge regulation model for SiO 2 surfaces with a single tunable parameter explains our measurements. This model may find general applicability in estimating the net charge of ionizable surfaces, given system parameters such as the dissociation or association constants of the ionizable groups and the pH, ionic strength, and dielectric constant of the solvent phase. Published by AIP Publishing. [http://dx

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Determination of the effective charge of individual colloidal particles

Cited by 48 publications

References 28 publications

Controlled assembly of single colloidal crystals using electro-osmotic micro-pumps

Controlled assembly of single colloidal crystals using electro-osmotic micro-pumps

Development of self-curable hybrid pigment inks by miniemulsion polymerization for inkjet printing of cotton fabrics

Measured electrical charge of SiO2 in polar and nonpolar media

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