Gelation in Model Colloid−Polymer Mixtures

Bergenholtz, Johan; Poon, Wilson; Fuchs, Matthias

doi:10.1021/la0340089

Cited by 183 publications

(191 citation statements)

References 87 publications

Supporting

Mentioning

176

Contrasting

Order By: Relevance

“…Indeed, in the gel phase, x 1 *(t) is approximately the range of attractive depletion potential. Localization on this scale is predicted by mode coupling theories of gelation [27,58].…”

Section: Discussionmentioning

confidence: 91%

Structure and dynamics of colloidal depletion gels: Coincidence of transitions and heterogeneity

2006

View full text Add to dashboard Cite

Transitions in structural heterogeneity of colloidal depletion gels formed through short-range attractive interactions are correlated with their dynamical arrest. The system is a density and refractive index matched suspension of 0.20 volume fraction poly(methyl methacyrlate) colloids with the non-adsorbing depletant polystyrene added at a size ratio of depletant to colloid of 0.043. As the strength of the short-range attractive interaction is increased, clusters become increasingly structurally heterogeneous, as characterized by number-density fluctuations, and dynamically immobilized, as characterized by the single-particle mean-squared displacement. The number of free colloids in the suspension also progressively declines. As an immobile cluster to gel transition is traversed, structural heterogeneity abruptly decreases. Simultaneously, the mean single-particle dynamics saturates at a localization length on the order of the short-range attractive potential range. Both immobile cluster and gel regimes show dynamical heterogeneity. Non-Gaussian distributions of single particle displacements reveal enhanced populations of dynamical trajectories localized on two different length scales. Similar dependencies of number density fluctuations, free particle number and dynamical length scales on the order of the range of short-range attraction suggests a collective structural origin of dynamic heterogeneity in colloidal gels.

show abstract

“…Indeed, in the gel phase, x 1 *(t) is approximately the range of attractive depletion potential. Localization on this scale is predicted by mode coupling theories of gelation [27,58].…”

Section: Discussionmentioning

confidence: 91%

Structure and dynamics of colloidal depletion gels: Coincidence of transitions and heterogeneity

2006

View full text Add to dashboard Cite

show abstract

“…This framework comprises colloid-polymer mixtures (Trappe et al, 2001;Dawson, 2002;Bergenholtz et al, 2003).…”

Section: Aggregation and Gelationmentioning

confidence: 99%

“…Figure 3 constitutes a phase diagram for the aggregated emulsions, since data plotted defines the boundary between fluid and solid-like states. It should be mentioned that typical diagrams of colloid-polymer mixtures are usually presented as volume fraction vs. polymer concentration (see, for instance, Bergenholtz et al, 2003). On the basis of the quantitative correlation given by Eq.…”

Section: Phase Behaviormentioning

confidence: 99%

“…Nevertheless, the lack of a coherent understanding of the phenomena involved usually led to semiempirical interpretations. The conceptual framework proposed in the recent literature clearly defines the role of particle concentration, interaction forces and shear stress in the aggregation and gelation of colloids (Trappe et al, 2001;Dawson, 2002;Bergenholtz et al, 2003). Relevant efforts have also been made to attain quantitative predictions of the rheometric functions in terms of colloidal interactions (see, for instance, Quemada and Berli, 2002).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Rheology and phase behavior of aggregating emulsions related to droplet-droplet interactions

Berli

2007

Braz. J. Chem. Eng.

View full text Add to dashboard Cite

-The present work deals with the relationship between colloidal interactions and physical properties of emulsions, in particular rheology and gel transition. Experimental data on protein-stabilized oil-in-water emulsions are considered. In this system, the excess of protein in the aqueous phase yields reversible droplet aggregation by the mechanism of depletion. Thus both phase and flow behaviors can be controlled by changing protein concentration, ionic strength and temperature. Calculations of the potential of interaction between droplets are carried out in the framework of colloid science. Particular emphasis is placed on the role that droplet-droplet interaction plays in defining the morphology of the aggregates, hence the microstructure and finally, the bulk physical properties. This understanding offers new perspectives in the study of complex food systems.

show abstract

“…Yet, the mechanisms of solidification at intermediate attraction strengths and low to intermediate densities are still not completely understood [16,17]. Especially the interplay of equilibrium phase transitions and aggregation effects is presently under scrutiny [7,8,18,19,20].…”

Section: Introductionmentioning

confidence: 99%

Bond formation and slow heterogeneous dynamics in adhesive spheres with long-ranged repulsion: Quantitative test of mode coupling theory

et al. 2007

Self Cite

View full text Add to dashboard Cite

A colloidal system of spheres interacting with both a deep and narrow attractive potential and a shallow long-ranged barrier exhibits a prepeak in the static structure factor. This peak can be related to an additional mesoscopic length scale of clusters and/or voids in the system. Simulation studies of this system have revealed that it vitrifies upon increasing the attraction into a gel-like solid at intermediate densities. The dynamics at the mesoscopic length scale corresponding to the prepeak represents the slowest mode in the system. Using mode coupling theory with all input directly taken from simulations, we reveal the mechanism for glassy arrest in the system at 40% packing fraction. The effects of the low-q peak and of polydispersity are considered in detail. We demonstrate that the local formation of physical bonds is the process whose slowing down causes arrest. It remains largely unaffected by the large-scale heterogeneities, and sets the clock for the slow cluster mode. Results from mode-coupling theory without adjustable parameters agree semi-quantitatively with the local density correlators but overestimate the lifetime of the mesoscopic structure (voids).

show abstract

Gelation in Model Colloid−Polymer Mixtures

Cited by 183 publications

References 87 publications

Structure and dynamics of colloidal depletion gels: Coincidence of transitions and heterogeneity

Structure and dynamics of colloidal depletion gels: Coincidence of transitions and heterogeneity

Rheology and phase behavior of aggregating emulsions related to droplet-droplet interactions

Bond formation and slow heterogeneous dynamics in adhesive spheres with long-ranged repulsion: Quantitative test of mode coupling theory

Contact Info

Product

Resources

About