Synthetic hectorite clay Laponite RD/XLG is composed of disk-shaped nanoparticles that acquire dissimilar charges when suspended in an aqueous medium. Owing to their property spontaneously self-assemble, used as a rheology modifier variety commercial water-based products. In particular, dispersion undergoes liquid-to-solid transition at about 1 vol % concentration. The evolution the physical properties transforms solid state reminiscent aging molecular well colloidal glasses. corresponding...

In this paper, the ageing behaviour of suspensions laponite with varying salt concentration is investigated using rheological tools. It observed that accompanied by an increase in complex viscosity. The creep experiments performed at various ages show damped oscillations strain. characteristic time scale oscillations, retardation time, shows a prominent decrease increasing age system. However, dependence weakens concentration, which known to change microstructure system from glass like gel...

Thixotropy is a phenomenon related to time dependent change in viscosity the presence or absence of flow. The yield stress, on other hand, represents minimum value stress above which steady flow can be sustained. In addition, material may also as function time. Both these characteristic features strongly influence state curve same. This study aims understand interrelation between thixotropy, and their relation with curve. this regard, we five thixotropic materials that show stress....

An aqueous dispersion of Laponite® has been studied in the literature for over past three decades. Typically, undergoes incessant evolution its microstructure, wherein elastic modulus and mean relaxation time show a continuous increase as function time. A considerable amount discussion revolved around nature this dispersion, specifically whether it can be classified repulsive Wigner glass state, characterized by disconnected particles stabilized electrostatic repulsions, or an attractive gel...

We study the aging behavior of aqueous suspension Laponite having 2.8 wt % concentration using rheological tools. At various salt all samples demonstrate orientational order when observed crossed polarizers. In experiments we observe inherent irreversibility in dynamics which forces system not to rejuvenate same state shear melting experiment carried out at a later date since preparation. The extensive as function time elapsed preparation self-similar trend irrespective salt. that...

We study aging behavior of an aqueous suspension Laponite as a function concentration Laponite, salt, time elapsed since preparation (idle time), and temperature by carrying extensive rheological conductivity experiments. observe that temporal evolution elastic moduli, which describes structural build-up aging, shifts to low times for experiments carried out higher greater temperature, longer idle while preserving the curvature in solid regime (elastic modulus than viscous modulus)....

The evolution of viscoelastic properties near the sol-gel transition is studied by performing oscillatory rheological measurements on two different types systems: a colloidal dispersion and thermo-responsive polymer solution under isothermal non-isothermal conditions. While undergoing transition, both systems pass through critical point. An approach to point characterized in terms divergence zero shear viscosity subsequent appearance low frequency modulus. In vicinity gel state, modulus show...

In this work, we study the rheological behavior of aqueous solution poly(vinyl alcohol) (PVOH) having different molecular weights and concentrations, which are subjected to freeze–thaw process. We observe that, during freezing step, PVOH undergoes a sol–gel transition upon decreasing temperature as defined by Winter criterion, wherein at critical point dynamic moduli show identical power-law dependence on frequency. During thawing with an increase in temperature, material gel–sol but higher...

Owing to nonlinear viscoelasticity, materials often show characteristic features that resemble those of thixotropy. This issue has been debated in the literature over past several decades, and experimental protocols have proposed distinguish thixotropy from viscoelasticity. In this work, we assess these by carrying out experiments using polymer solutions, thixotropic clay dispersions, modeling their behavior, respectively, FENE-P constitutive equation a viscoelastic aging model. We find...

We study the aging behavior of aqueous laponite suspension, a model soft glassy material, in creep. observe that viscoelastic is time dependent and strongly influenced by deformation field; effect known to arise due rejuvenation. show irrespective strength field (shear stress) age, when imposed scale normalized with dominating relaxation mode system, universal obtained, demonstrating time-stress superposition, phenomenon may be generic variety materials.

We present an effective time approach to predict long and short rheological behavior of soft glassy materials from experiments carried out over practical scales. Effective takes advantage relaxation dependence on aging that allows time-aging superposition even when occurs the experimental Interestingly, a variety demonstrate successfully predicts for diverse regimes ranging subaging hyperaging behaviors. This can also be used any response function in molecular as well spin glasses.

We investigate the stress relaxation behavior on application of step strains to aging aqueous suspensions synthetic clay Laponite. The exhibits a two-step decay, from which slow modes are extracted as functions sample ages and applied strain deformations. Interestingly, time scales that we estimate show dramatic enhancement with increasing amplitudes. argue system ends up exploring deeper sections its energy landscape following strain.

The interparticle interactions in colloidal suspensions of charged disks Laponite clay water were investigated using dynamic light scattering (DLS) and Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. We studied the effects concentration (CL), externally added salt (CS), temperature (T) on microscopic dynamics suspensions. fast (τ1) mean slow relaxation times (⟨τww⟩) extracted from intensity autocorrelation functions measured at different waiting (tw) after sample preparation. Comprehensive...

Investigating microstructure of suspensions with particles having anisotropic shape that share complex interactions is a challenging task leading to competing claims. This work investigates phase behavior one such system: aqueous Laponite suspension, which highly contested in the literature, using rheological and microscopic tools. Remarkably, we observe over broad range (1.4 4 weight %) salt concentrations (0 7 mM), system overwhelmingly demonstrates all characteristics sol-gel transition...

In this work, we investigate signatures of physical aging in an aqueous dispersion Carbopol that shows yield stress and weak enhancement elastic modulus as a function time. We observe the creep curves, well strain recovery, show significant dependence on waiting time elapsed since shear melting. The corrected strain, which is excess recovered has been observed to time–waiting superposition effective domain, wherein normalized by dependent relaxation power-law dependence. corresponding power...