Long-lived neighbors determine the rheological response of glasses

Abstract

Glasses exhibit a liquid-like structure but a solid-like rheological response with plastic deformations only occurring beyond yielding. Thus, predicting the rheological behavior from the microscopic structure is difficult, but important for materials science. Here, we consider colloidal suspensions and propose to supplement the static structural information with the local dynamics, namely the rearrangement and breaking of the cage of neighbors. This is quantified by the mean squared nonaffine displacement and the number of particles that remain nearest neighbors for a long time, i.e. long-lived neighbors, respectively. Both quantities are followed under shear using confocal microscopy and are the basis to calculate the affine and nonaffine contributions to the elastic stress, which is complemented by the viscous stress to give the total stress. During start-up of shear, the model predicts three transient regimes that result from the interplay of affine, nonaffine and viscous contributions. Our prediction quantitatively agrees with rheological data and their dependencies on volume fraction and shear rate.

5 pages, 3 figures, Accepted for publication in Phys. Rev. Lett. Supplemental Information available as ancillary file

References in corpus (10)

• In Search of Colloidal Hard Spheres
• Three-dimensional imaging of colloidal glasses under steady shear
• Stress localization, stiffening and yielding in a model colloidal gel
• Confocal microscopy of colloidal particles: towards reliable, optimum coordinates
• From Equilibrium to Steady State: The Transient Dynamics of Colloidal Liquids under Shear
• Relaxation in yield stress systems through elastically interacting activated events
• Overshoots in stress strain curves: Colloid experiments and schematic mode coupling theory
• Microscopic origin of nonlinear non-affine deformation and stress overshoot in bulk metallic glasses
• Start-up Shear of Concentrated Colloidal Hard Spheres: Stresses, Dynamics and Structure
• Yielding of binary colloidal glasses

Cited by in corpus (15)

• Plasticity in amorphous solids is mediated by topological defects in the displacement field
• Slow stretched-exponential and fast compressed-exponential relaxation from local event dynamics
• Stress Overshoots in Simple Yield Stress Fluids
• Nonlinear Oscillatory Shear Tests in Viscoelastic Holography
• Universal $L^{-3}$ finite-size effects in the viscoelasticity of confined amorphous systems
• Distance-as-time in physical aging
• Nonaffine deformation and tunable yielding of colloidal assemblies at the air-water interface
• Triple junction at the triple point resolved on the individual particle level
• Continuum modelling of shear start-up in soft glassy materials
• Fragility and thermal expansion control crystal melting and the glass transition
• Localized elasticity governs the nonlinear rheology of colloidal supercooled liquids
• Rheology of Hard Glassy Materials
• Connecting Shear Thinning and Dynamic Heterogeneity in Supercooled Liquids by Localized Elasticity
• Vibrational density of states of amorphous solids with long-ranged power-law correlated disorder in elasticity
• Understanding Flow Behaviors of Supercooled Liquids by Embodying Solid-Liquid Duality at Particle Level