相关论文: Ring-Driven Shear Thickening in Wormlike Micelles?
The past few years have seen many advances in our understanding of the dynamics of polymeric fluids. These include improvements on the successful reptation theory; an emerging molecular theory of semiflexible chain dynamics; and an…
Suspensions are of wide interest and form the basis for many smart fluids. For most suspensions, the viscosity decreases with increasing shear rate, i.e. they shear thin. Few are reported to do the opposite, i.e. shear thicken, despite the…
Flow-induced configuration dynamics and scission of rodlike micelles are studied for the first time using molecular dynamics simulations in presence of explicit solvent and salt. Predicted dependence of tumbling frequency and orientation…
We study the dynamics of a spherical steel ball falling freely through a solution of entangled wormlike-micelles. If the sphere diameter is larger than a threshold value, the settling velocity shows repeated short oscillatory bursts…
Giant micelles are elongated, polymer-like objects created by the self-assembly of amphiphilic molecules (such as detergents) in solution. Giant micelles are typically flexible, and can become highly entangled even at modest concentrations.…
In the past fifteen years, flow instabilities reminiscent of the Taylor-like instabilities driven by hoop stresses, have been observed in wormlike micelles based on surfactant molecules. In particular, purely elastic instabilities and…
We study the rheology of cornstarch suspensions, a dense system of non-Brownian particles that exhibits shear thickening, i.e. a viscosity that increases with increasing shear rate. Using MRI velocimetry we show that the suspension has a…
Shear thickening, an increase of viscosity with shear rate, is a ubiquitous phenomena in suspended materials that has implications for broad technological applications. Controlling this thickening behavior remains a major challenge and has…
We use a hybrid method that combines the Multiparticle collision dynamics (MPCD) for solvent particles with the molecular dynamics for equilibrium polymers to simulate the shearing of the equilibrium polymers (or Wormlike micelles) at a…
Despite the extensive research that has been conducted for decades on the behavior of confined liquids, detailed knowledge of this phenomenon, particularly in the mixed/boundary lubrication regime, remains limited. This can be attributed to…
Hypotheses: The aggregation number and length of spherocylindrical (rodlike, wormlike) micelles in solutions of an ionic surfactant and salt can be predicted knowing the molecular parameters and the input concentrations of the species. This…
Hypothesis Understanding the scission of rod-like micelles under mechanical forces is crucial for optimizing their stability and behavior in industrial applications. This study investigates how micelle length, flexibility, and external…
The interplay between shear band (SB) formation and boundary conditions (BC) is investigated in wormlike micellar systems (CPyCl--NaSal) using ultrasonic velocimetry coupled to standard rheology in Couette geometry. Time-resolved velocity…
The influence of a stationary shear flow on the crystallization in a glassy system is studied by means of molecular dynamics simulations and subsequent cluster analysis. The results reveal two opposite effects of the shear flow on the…
Several surfactant molecules self-assemble in solution to form long, cylindrical, flexible wormlike micelles. These micelles can be entangled with each other leading to viscoelastic phases. The rheological properties of such phases are very…
We investigate wrinkling of two-dimensional random and triangular semiflexible polymer networks under shear. Both types of semiflexible networks exhibit wrinkling above a small critical shear angle, which scales with an exponent of the…
We investigate the nucleation and propagation of cracks in self-assembled viscoelastic fluids, which are made of surfactant micelles reversibly linked by telechelic polymers. The morphology of the micelles can be continuously tuned, from…
Microrheology experiments show that viscoelastic media composed by wormlike micellar networks display complex relaxations lasting seconds even at the scale of micrometers. By mapping a model of patchy colloids with suitable mesoscopic…
We report the flow dynamics of two shear-banding wormlike micellar solutions with distinct surfactant chemistries in a Taylor-Couette (TC) setup following a startup shear. The solutions, formulated with CTAB/NaSal and CPyCl/NaSal, exhibit…
We develop a microscopic picture of shear thickening in dense suspensions which emphasizes the role of frictional forces, coupling rotational and translational degrees of freedom. Simulations with contact forces and viscous drag only,…