Association Colloids and their Equilibrium Modelling

Leermakers, F.A.M.; Eriksson, Jan Christer; Lyklema, J.

doi:10.1016/s1874-5679(05)80008-x

Cited by 40 publications

(43 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[24] The carboxylic group X ¼ COO dissociates with corresponding operational dissociation constant p Table 1 and is inspired by earlier (surfactant) micellization studies. [28,29] A negative value for a x parameter indicates attractive interactions, whereas positive values for x parameters indicate repulsive interactions. Interactions with the solvent are important and are chosen such that polar groups have a small or negative x, whereas the apolar ones have a large positive value as detailed below.…”

Section: Modeling Parametersmentioning

confidence: 99%

See 1 more Smart Citation

Self-Organization of Polyurethane Pre-Polymers as Studied by Self-Consistent Field Theory

Tuinier

Casteren

et al. 2015

Macromol. Theory Simul.

View full text Add to dashboard Cite

Using self‐consistent field (SCF) theory, we studied the self‐assembly characteristics of polyurethane pre‐polymer dispersions in aqueous solutions. With a molecularly detailed model implementing the Scheutjens–Fleer discretization scheme, it is shown how the stability, equilibrium size, and internal structure of the (swollen) micelles in polyurethane (PU) dispersions depend on the chemical structure and the molecular composition of the charged pre‐polymer mixtures. The stability region of these micelles is found to increase when acid groups become deprotonated and when the ionic strength is lowered. Insight into the physical–chemical behavior of PU pre‐polymer dispersions is important for the subsequent process of film formation from the PU dispersions for the final coating properties.

show abstract

Section: Modeling Parametersmentioning

confidence: 99%

“…We further implemented a small repulsion between C and R, which is not uncommon as, e.g., CH 3 and CH 2 also appear to repel each other. [28,29] Further, there is a significant repulsion between O units and apolar units:…”

Section: Modeling Parametersmentioning

confidence: 99%

Self-Organization of Polyurethane Pre-Polymers as Studied by Self-Consistent Field Theory

Tuinier

Casteren

et al. 2015

Macromol. Theory Simul.

View full text Add to dashboard Cite

show abstract

“…SCF theory has been extensively discussed elsewhere [21][22][23][24][25]. The calculations yield, e.g., electrostatic potential and concentration profiles, chemical potentials, and the free energy of the system.…”

mentioning

confidence: 99%

On the Repulsive Interaction Between Strongly Overlapping Double Layers of Charge-regulated Surfaces

Philipse

Tuinier

Kuipers

et al. 2017

Colloid and Interface Science Communications

View full text Add to dashboard Cite

A B S T R A C TThe Donnan equilibrium is employed to evaluate the entropic repulsion between two charged plates that feature charge regulation and are in equilibrium with a reservoir solution of monovalent salt. This approach represents the zero-field limit of the Poisson-Boltzmann equation, valid for strongly overlapping electrical double layers. We show that this scenario features an intrinsic length scale, which serves as the unscreened pendant of the Debye length for strongly overlapping double layers. In general, the scaling of the disjoining pressure with interplate distance is dependent on the boundary conditions (constant charge, constant potential, or charge regulation). Surprisingly, here we find for sufficiently low potentials the same inverse-square decay as for constant charge surfaces. We test the validity of the zero-field limit by comparison with self-consistent field lattice computations that invoke the full Poisson equation for finitely sized ions between two charge-regulated plates.The electrical double-layer repulsion between two charged surfaces in equilibrium with a salt reservoir is conventionally [1-10] evaluated under the assumption that surfaces are sufficiently far apart such that their double-layers only weakly interact. This so-called 'weak-overlap approximation' [4] implies that the electrical potential in the mid-plane between the two surfaces is small (though surface potentials, nevertheless, may be high). Within this weak-overlap approximation, the Poisson-Boltzmann (PB) equation eventually yields osmotic disjoining pressures that decay exponentially; the typical decay length being the Debye screening length κ −1 which measures the thickness of a diffuse electrical double-layer in solution. Together with Van der Waals attractions, one arrives at the exponentially screened, classical DLVO potential [1][2][3][4], which is applicable to dilute colloidal fluids in which the average colloid-colloid distance is (much) larger than κ −1 .When distances between charged surfaces are comparable to or less than κ −1 such that double-layers strongly overlap and the weak-overlap approximation breaks down, one must resort to more complicated solutions containing elliptic functions [11] or to numerical solutions. For low surface potentials with plates in close proximity and in presence of background salt, analytical approximations exist featuring a peculiar inverse square decay of the disjoining pressure with the inter-plate separation [11]. To the best of our knowledge, however, these approximations are only known for the boundary condition of constant surface charge [11-13], but not for surfaces featuring charge regulation, even though these boundary conditions in general do not lead to the same scaling behavior of the disjoining pressure [14]. It should be mentioned that an inverse square decay is also known for the salt-free (counter-ion only) limit at large separations, even in case of charge regulation [11,15]. Here we demonstrate a relatively straightforward and analytical treatment of th...

show abstract

“…From the above it is evident that it is necessary to analyze the grand potential Ω of the micelle as a function of g [1,31]. In Fig.2 we present, as an example, SF-SCF results for the grand potential for a spherical micelle composed with g PLGA 60 PEO 60 PLGA 60 copolymers.…”

Section: Grand Potential and Equilibrium Micellementioning

confidence: 99%

Self-consistent field predictions for quenched spherical biocompatible triblock copolymer micelles

et al. 2013

View full text Add to dashboard Cite

We have used the Scheutjens-Fleer self-consistent field (SF-SCF) method to predict the self-assembly of triblock copolymers with a solvophilic middle block and sufficiently long solvophobic outer blocks. We model copolymers consisting of polyethylene oxide (PEO) as solvophilic block and poly(lactic-co-glycolic) acid (PLGA) or poly(ǫ-caprolactone) (PCL) as solvophobic block. These copolymers form structurally quenched spherical micelles provided the solvophilic block is long enough. Predictions are calibrated on experimental data for micelles composed of PCL-PEO-PCL and PLGA-PEO-PLGA triblock copolymers prepared via the nanoprecipitation method. We establish effective interaction parameters that enable us to predict various micelle properties such as the hydrodynamic size, the aggregation number and the loading capacity of the micelles for hydrophobic species that are consistent with experimental finding.

show abstract

Association Colloids and their Equilibrium Modelling

Cited by 40 publications

References 7 publications

Self-Organization of Polyurethane Pre-Polymers as Studied by Self-Consistent Field Theory

Self-Organization of Polyurethane Pre-Polymers as Studied by Self-Consistent Field Theory

On the Repulsive Interaction Between Strongly Overlapping Double Layers of Charge-regulated Surfaces

Self-consistent field predictions for quenched spherical biocompatible triblock copolymer micelles

Contact Info

Product

Resources

About