(464i) The Rheology and Microstructure of an Aging Thermoreversible Colloidal Gel
In this work, we quantitatively relate rheological aging to structural aging by simultaneously measuring the bulk properties and gel microstructure using rheometry and small angle neutron scattering (Rheo-SANS), respectively . Specifically, we develop a quantitative and predictive relationship between the macroscopic properties and the underlying microstructure (i.e.the effective strength of attraction) of an aging colloidal gel, which is independent of the gelâ??s thermal and shear history. Analysis with mode coupling theory is consistent with local particle rearrangements as the mechanism of aging, which lead to monotonically increasing interaction strengths in a continuously evolving gel and strongly support aging as a trajectory in the free energy landscape. The analyses and conclusions of this study may be 1) industrially relevant to products that age on commercial timescales, such as paints and pharmaceuticals, 2) applicable to other dynamically arrested systems, such as metallic glasses, and 3) used in the design of new materials.
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 Gordon, M.B., Kloxin, C.J., and Wagner, N.J., "Rheology and Microstructure of an Aging Thermoreversible Colloidal Gel," Journal of Rheology. Submitted.