Rheological Behavior of Colloidal Silica Dispersion: Irreversible Aging and Thixotropy
arXiv:2511.01212 · doi:10.1021/acs.langmuir.5c02136
Abstract
In this work, we study the rheological behavior of colloidal dispersion of charge-screened nanoparticles of silica suspended in aqueous media that exhibits soft solid-like consistency. We observe that the system shows various characteristics of physical aging wherein it undergoes time evolution of rheological properties such as elastic modulus, relaxation time, and yield stress subsequent to shear melting of the same. Notably, the relaxation time increases more strongly than linearly with time, which is suggestive of hyper-aging dynamics. When considered along with the time-dependent yield stress, this behavior indicates the steady state shear stress-shear rate flow curve to be non-monotonic with a negative slope in a lower shear rate region. Performing shear melting on this system at a later date since the preparation of the dispersion (rest time) results in higher viscosity as well as yield stress, and the corresponding evolution of the elastic modulus shifts to lower times. This implies that physical aging in studied silica dispersion, while reversible over short time scales (of the order of hours), becomes irreversible over longer durations (days) owing to the inability of strong shear to break interparticle bonds that have strengthened over long durations. We also develop a thixotropic structural kinetic model within a time-dependent Maxwell framework that captures the experimentally observed rheological behavior well.
References in corpus (20)
- The Physics of the Colloidal Glass Transition
- Ageing and Rheology in Soft Materials
- Slow dynamics in glassy soft matter
- Rejuvenation and overaging in a colloidal glass under shear
- Irreversible Aging Dynamics and Generic Phase Behavior of Aqueous Suspensions of Laponite
- Prediction of long and short time rheological behavior in soft glassy materials
- Avalanche-like fluidization of a non-Brownian particle gel
- Hyper-aging Dynamics of Nano-clay Suspension
- Ductile-to-brittle transition and yielding in soft amorphous materials: perspectives and open questions
- Signatures of Physical Aging and Thixotropy in Aqueous Dispersion of Carbopol
- Distinguishing thixotropy from viscoelasticity
- On the Nature of Flow Curve and Categorization of Thixotropic Yield Stress Materials
- A Model for Aging under Deformation Field, Residual Stresses and Strains in Soft Glassy Materials
- Aging after shear rejuvenation in a soft glassy colloidal suspension: evidence for two different regimes
- Linear Viscoelasticity of Soft Glassy Materials
- Residual stresses and shear-induced overaging in boehmite gels
- Thixotropy, non-monotonic stress relaxation, and the second law of thermodynamics
- Delayed solidification of soft glasses: New experiments, and a theoretical challenge
- Long Time Response of Aging Glassy Polymers
- Effect of sodium pyrophosphate and understanding microstructure of aqueous LAPONITE(R) dispersion using dissolution study