Tracer-diffusion in binary colloidal hard-sphere suspensions

2002 ◽  
Vol 117 (12) ◽  
pp. 5908-5920 ◽  
Author(s):  
Haiyan Zhang ◽  
Gerhard Nägele
Keyword(s):  
Hard Sphere ◽  
Tracer Diffusion ◽  
Sphere Suspensions

scholarly journals Anomalous tracer diffusion in hard-sphere suspensions

2021 ◽  
Author(s):  
Stephen Peppin
Keyword(s):  
Hard Sphere ◽  
Structural Heterogeneity ◽  
Tracer Diffusion ◽  
Host Matrix ◽  
Uphill Diffusion ◽  
Cross Diffusion ◽  
Coupled Equations ◽  
Tracer Particles ◽  
Sphere Suspensions ◽  
Matrix Concentration

Coupled equations describing diffusion and cross-diffusion of tracer particles in hard-sphere suspensions are derived and solved numerically. In concentrated systems with strong excluded volume and viscous interactions the tracer motion is subdiffusive. Cross diffusion generates transient perturbations to the host-particle matrix, which affect the motion of the tracer particles leading to nonlinear mean squared displacements. Above a critical host-matrix concentration the tracers experience clustering and uphill diffusion, moving in opposition to their own concentration gradient. A linear stability analysis indicates that cross diffusion can lead to unstable concentration fluctuations in the suspension. The instability is a potential mechanism for the appearance of dynamic and structural heterogeneity in suspensions near the glass transition.

Theory of tracer diffusion in concentrated hard-sphere suspensions

2019 ◽  
Vol 870 ◽  
pp. 1105-1126 ◽  
Author(s):  
S. S. L. Peppin
Keyword(s):  
Glass Transition ◽  
Hard Sphere ◽  
Volume Fraction ◽  
Pore Space ◽  
Particle Volume Fraction ◽  
Tracer Diffusion ◽  
Tracer Diffusivity ◽  
Particle Volume ◽  
Cross Diffusion ◽  
Sphere Suspensions

A phenomenological theory of diffusion and cross-diffusion of tracer particles in concentrated hard-sphere suspensions is developed. Expressions for the diffusion coefficients as functions of the host particle volume fraction are obtained up to the close-packing limit. In concentrated systems the tracer diffusivity decreases because of the reduced pore space available for diffusion. The tracer diffusivity can be modelled by a Stokes–Einstein equation with an effective viscosity that depends on the pore size. Tracer diffusion and segregation during sedimentation cease at a critical trapping volume fraction corresponding to a tracer glass transition. The tracer cross-diffusion coefficient, however, increases near the glass transition and diverges in the close-packed limit.

The first normal stress difference of non-Brownian hard-sphere suspensions in the oscillatory shear flow near the liquid and crystal coexistence region

Soft Matter ◽  
2020 ◽  
Vol 16 (43) ◽  
pp. 9864-9875
Author(s):  
Young Ki Lee ◽  
Kyu Hyun ◽  
Kyung Hyun Ahn
Keyword(s):  
Shear Flow ◽  
Normal Stress ◽  
Hard Sphere ◽  
Normal Stress Difference ◽  
Oscillatory Shear ◽  
Stress Difference ◽  
Large Amplitude Oscillatory Shear ◽  
First Normal Stress Difference ◽  
Oscillatory Shear Flow ◽  
Sphere Suspensions

The first normal stress difference (N1) as well as shear stress of non-Brownian hard-sphere suspensions in small to large amplitude oscillatory shear flow is investigated.

Three-particle contribution to sedimentation and collective diffusion in hard-sphere suspensions

2002 ◽  
Vol 117 (3) ◽  
pp. 1231-1241 ◽  
Author(s):  
B. Cichocki ◽  
M. L. Ekiel-Jeżewska ◽  
P. Szymczak ◽  
E. Wajnryb
Keyword(s):  
Hard Sphere ◽  
Sphere Suspensions

Viscosity of Hard-Sphere Suspensions:  Can We Go Lower?

2006 ◽  
Vol 45 (21) ◽  
pp. 6906-6914 ◽  
Author(s):  
Vijay Gopalakrishnan ◽  
Charles F. Zukoski
Keyword(s):  
Hard Sphere ◽  
Sphere Suspensions

Dynamic Simulations of Hard-Sphere Suspensions Under Steady Shear

1993 ◽  
Vol 21 (3) ◽  
pp. 363-368 ◽  
Author(s):  
J. M. V. A Koelman ◽  
P. J Hoogerbrugge
Keyword(s):  
Hard Sphere ◽  
Steady Shear ◽  
Dynamic Simulations ◽  
Sphere Suspensions
Sign in / Sign up

Export Citation Format

Share Document