Gelation as arrested phase separation in short-ranged attractive colloid--polymer mixtures
نویسندگان
چکیده
We present further evidence that gelation is an arrested phase separation in attractive colloid-polymer mixtures, based on a method combining confocal microscopy experiments with numerical simulations recently established in Nature 453, 499 (2008). Our results are independent of the form of the interparticle attractive potential, and therefore should apply broadly to any attractive particle system with short-ranged, isotropic attractions. We also give additional characterization of the gel states in terms of their structure, inhomogeneous character and local density.
منابع مشابه
Crystallization and gelation in colloidal systems with short-ranged attractive interactions.
We systematically study the relationship between equilibrium and nonequilibrium phase diagrams of a system of short-ranged attractive colloids. Using Monte Carlo and Brownian dynamics simulations we find a window of enhanced crystallization that is limited at high interaction strength by a slowing down of the dynamics and at low interaction strength by the high nucleation barrier. We find that ...
متن کاملThe role of long-range forces in the phase behavior of colloids and proteins
The role of long-range forces in the phase behavior of colloids and proteins. Abstract. – The phase behavior of colloid-polymer mixtures, and of solutions of globular proteins, is often interpreted in terms of a simple model of hard spheres with short-ranged attraction. While such a model yields a qualitative understanding of the generic phase diagrams of both colloids and proteins, it fails to...
متن کاملStructure, dynamics, and rheology of colloid-polymer mixtures: from liquids to gels.
We investigate the structural, dynamical, and viscoelastic properties of colloid-polymer mixtures at intermediate colloid volume fraction and varying polymer concentrations, thereby tuning the attractive interactions. Within the examined range of polymer concentrations, the samples varied from fluids to gels. In the liquid phase, an increasing correlation length of the density fluctuations when...
متن کاملGelation in Model Colloid-Polymer Mixtures
Mode coupling theory (MCT) is used to model gel formation in mixtures of colloidal particles and nonadsorbing polymer. The polymer induces an effective, short-range attraction among the colloids, which is modeled by a depletion attraction of the Asakura-Oosawa form. This enables the MCT to be solved analytically for dilute systems, leading to a prediction, free of adjustable parameters, of the ...
متن کاملThe role of polymer polydispersity in phase separation and gelation in colloid-polymer mixtures.
Mixtures of nonadsorbing polymer and colloidal particles exhibit a range of different morphologies depending on the particle and polymer concentrations and their relative size ratios. These can be very important for technological applications, where gelation can produce a weak solidlike structure that can help reduce phase separation, extending product shelf life. However, industrial products a...
متن کامل