Jamming phase diagram for attractive particles
Original Entry: Nick Chisholm, AP 225, Fall 2009
Authors: V. Trappe, V. Prasad, Luca Cipelletti, P.N. Segre, and D. A. Weitz
Publication: Nature 411 772-775 (2001)
Soft Matter Keywords
Colloid, Elastic Modulus, Jamming Transition, Stress, Viscosity
In this article, the authors present experimental evidence supporting theoretical proposals (see Figure 1) suggesting that a jamming phase diagram could be used in order to describe attractive particle systems, where the attractive interactions play a role similar to that of confining pressure. The fluid-to-solid transition of weakly attractive colloid particles is studied in detail, and the results conclude that they undergo a similar gelation behavior (when compared to granular media, colloidal suspensions, and molecular systems which are described by jamming phase diagrams) with increasing concentration and decreasing thermalization or stress. The authors thus claim that their results support the idea of a jamming phase diagram for attractive colloid particles, providing a unifying link between the glass transition, gelation, and aggregation.
Please see the definition of Jamming Transition before continuing to read this article review.
Soft Matter Discussion
The authors used data from three very different colloid systems (namely, carbon black, polymethyl methacrylate (PMMA), and polystyrene) in order to create the phase diagram as shown in Figure 2. As is very clear from the diagram, it was found that as one increases density, or decreases temperature or applied stress, the particles jam. The solvent is treated as an inert background, and thus the density is set explicitly by the volume fraction <math>\phi</math>.
 V. Trappe, V. Prasad, Luca Cipelletti, P.N. Segre, and D. A. Weitz, "Jamming phase diagram for attractive particles," Nature 411 772-775 (2001).