Monday, December 18, 20063:00 PM - 4:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Stressing Glasses with Gels
Dan BlairHarvard University
We employ a novel technique to for the application of external stress on glassy suspensions of colloidal particles. By placing a confined Poly-NIPAM hydrogel in contact with a colloidal glass, uniaxial strains of up to ten percent are imposed. This external strain subsequently increases the overall volume fraction above the glass transition, and approaches the close packed limit. Using laser scanning confocal microscopy, we directly measure the local strain tensor, and the dynamics of localized shear/compressive transformations. We observe the appearance of strain heterogeneities that grow with increased strain. We will present results on the analysis of the local volume and dynamical properties of these heterogeneities and postulate their equivalence to characteristic features of analogous systems near the jamming transition.
Host: Robert Ecke, T-CNLS