Aging after shear rejuvenation in a soft glassy colloidal suspension: Evidence for two different regimes

Abstract

The aging dynamics after shear rejuvenation in a glassy, charged clay suspension have been investigated through dynamic light scattering (DLS). Two different aging regimes are observed: one is attained if the sample is rejuvenated before its gelation and one after the rejuvenation of the gelled sample. In the first regime, the application of shear fully rejuvenates the sample, as the system dynamics soon after shear cessation follow the same aging evolution characteristic of normal aging. In the second regime, aging proceeds very fast after shear rejuvenation, and classical DLS cannot be used. An original protocol to measure an ensemble averaged intensity correlation function is proposed and its consistency with classical DLS is verified. The fast aging dynamics of rejuvenated gelled samples exhibit a power law dependence of the slow relaxation time on the waiting time.

Statistical properties of entropy-consuming fluctuations in jammed states of laponite suspensions: Fluctuation relations and generalized Gumbel distribution

“…At low values of applied stress, the viscosity increases with time (called aging), whereas at higher stress values, the viscosity decreases with time (called rejuvenation) [19]. Other rheological studies of laponite suspensions focusing on thixotropy, aging, and rejuvenation under applied shear have been widely studied in the past few years [20][21][22][23][24][25][26][27][28].…”

Shear-induced fragmentation of laponite suspensions

“…The nonlinear rheology of Laponite suspensions has also been intensively studied with emphasis on thixotropy and ageing or rejuvenation under shear [27,44,45,46,47,48,49,50,51]. A few experiments have hinted to the presence of shear localization in the vicinity of the yield stress in Laponite samples [19,52,53], which provided support for discontinuous models of the yielding transition [10,26].…”

Measurement of the Four-Point Susceptibility of an Out-of-Equilibrium Colloidal Solution of Nanoparticles Using Time-Resolved Light Scattering

“…The experiment is performed on an aging low-concentration colloidal solution of Laponite, which is a synthetic clay that has been studied intensively for its rich dynamic and structural behavior [9,10] as well as numerous applications [11]. Due to its simple preparation procedure, this colloidal system is useful for experimentally elucidating the basic physics soft materials with complex viscoelasticity [12].…”