Gelation on the microscopic scale.

Size dependence of microprobe dynamics during gelation of a discotic colloidal clay

oft materials, such as gels and colloidal glasses, often exhibit different rheological properties at ulk and microscopic scales as a result of their complex microstructure. This phenomenon has ecently been demonstrated for a gel-forming aqueous dispersion of Laponite clay Oppong et al. hys. Rev. E 78, 021405 2008 . For this material, microrheology reveals a significantly weaker el and a longer ...

Ultra-long-range dynamic correlations in a microscopic model for aging gels.

We use large-scale computer simulations to explore the nonequilibrium aging dynamics in a microscopic model for colloidal gels. We find that gelation resulting from a kinetically arrested phase separation is accompanied by "anomalous" particle dynamics revealed by superdiffusive particle motion and compressed exponential relaxation of time correlation functions. Spatiotemporal analysis of the d...

Reversible Gelation and Glass Transition: Towards a microscopic model of reversible polymer gel

Gelation Time of Hexamethylenetetramine Polymer Gels Used in Water Shutoff Treatment

Among the methods available to reduce water production, injecting a gelling system composed of a polymer and a crosslinker has been widely used. In this work, a hydrogel was prepared by crosslinking of an aqueous solution containing hexamethylenetetramine (HMTA) as crosslinker, hydrochloric acid (HCl) as an activator, and the co-polymer of 2-acrylamido-2methyl-propanesulfonic-acid sodium salt (...

Glasslike kinetic arrest at the colloidal-gelation transition.

We show that gelation of weakly attractive colloids is remarkably similar to the colloidal glass transition. Like the glass transition, dynamic light scattering functions near gelation scale with scattering vector, and exhibits a two-step decay with a power-law divergence of the final decay time. Like the glass transition, static light scattering does not change upon gelation. These results sug...