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 ...

We study the existence of global-in-time weak solutions to a coupled microscopicmacroscopic bead-spring model with microscopic cut-off, which arises from the kinetic theory of dilute solutions of polymeric liquids with noninteracting polymer chains. The model consists of the unsteady incompressible Navier–Stokes equations in a bounded domain Ω ⊂ Rd, d = 2 or 3, for the velocity and the pressure...

We report here the first experimental measurements of nonlinear rheological material properties of hagfish slime, a hydrated biopolymer/biofiber network, and develop a microstructural constitutive model to explain the observed nonlinear viscoelastic behavior. The linear elastic modulus of the network is observed to be G′ ≈ 0.02 Pa for timescales 0.1 s ≤ t ≤ 10 s, making it one of the softest el...

In this paper, the two-dimensional Kelvin–Helmholtz (KH) instability occurring in shear flow of polymer fluids is modeled by dissipative particle dynamics (DPD) method at coarse-grained molecular level. A revised FENE model proposed to properly describe chains. model, elastic repulsion and tension are both considered between adjacent beads, bond length which set as one segment’s equilibrium len...

A multi-scale phase-field approach, which couples the mesoscopic crystallization with the microscopic orientation of chain segments and macroscopic viscoelastic melt flow, is proposed to study how the crystal growth of semi-crystalline polymers is affected by flows. To make the simulation feasible, we divide the problem into three parts. In the first part, a finitely extensible nonlinear elasti...

Aqueous surfactant solutions are known to form elongated micelles under certain thermodynamic conditions characterized by surfactant concentration, salinity or temperature [1,2]. In the semidilute regime these linear and flexible particles, with persistence lengths varying from 15 to 150 nm [3], form an entangled viscoelastic network. Recently observed phenomena such as shear banding structure,...