scholarly journals Microgels as viscosity modifiers influence lubrication performance of continuum

Soft Matter ◽  
2019 ◽  
Vol 15 (47) ◽  
pp. 9614-9624 ◽  
Author(s):  
Efren Andablo-Reyes ◽  
Demetra Yerani ◽  
Ming Fu ◽  
Evangelos Liamas ◽  
Simon Connell ◽  
...  
Keyword(s):  
Tribological Performance ◽  
High Shear ◽  
Shear Rheology ◽  
Lubrication Performance ◽  
Viscosity Modifiers ◽  
High Shear Rheology ◽  
The Continuum

Biocompatible microgels modify the rheology of continuum acting as thickening or thinning agents. Here, the influence of high shear rheology of microgels on tribological performance of the continuum is demonstrated.

High Shear Rheology and Anisotropy in Concentrated Solutions of Monoclonal Antibodies

2013 ◽  
Vol 102 (8) ◽  
pp. 2538-2549 ◽  
Author(s):  
Isidro E. Zarraga ◽  
Rosalynn Taing ◽  
Jonathan Zarzar ◽  
Jacob Luoma ◽  
Jenny Hsiung ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
High Shear ◽  
Concentrated Solutions ◽  
Shear Rheology ◽  
High Shear Rheology

Rheology of Nanofluids in Microchannels

2008 ◽  
Author(s):  
Fre´de´ric Ayela ◽  
Olivier Tillement ◽  
Julien Chevalier
Keyword(s):  
Rheological Properties ◽  
Peclet Number ◽  
High Shear ◽  
Shear Rheology ◽  
Péclet Number ◽  
Shear Rates ◽  
High Shear Rates ◽  
On Chip ◽  
Very High ◽  
High Shear Rheology

Microfluidics is often presented for applications where only microliters sample volumes are available. But the benefits of microchannels do not reduce to a low consumption of fluids. From a physical and mechanical point of view, microfluidics can offer high shear rates combined with low Reynolds number and low viscous heating. It becomes possible to explore high shear rheology on a lab-on-chip. We have micromachined microviscometers to study the rheological properties of nanofluids under very high shear rates conditions. Nanofluids are fluid suspensions of solid nanoparticles. Recent experiments have indicated an anomalous increase in thermal conductivity of these suspensions. But less attention has been payed to the rheological properties of nanofluids. The few results concerning the viscosity of nanofluids exhibit scattered values higher than those of fluid suspensions of microparticles, because of a higher rate of collisions due to Brownian motion and shearing motion which enhance aggregation. These experiments were performed with commercially available rheometers over a limited range of shear rates. Our viscometers on chip are silicon — Pyrex microchannels (H ≈ 10 – 20 μm) equipped with local pressure drop sensors. Nanofluids under test were ethanol-based SiO2 nanoparticles. For particle sizes from 20 nm to 190 nm, and solid volume fractions from 1.4% to 7%, a newtonian behaviour has been observed up to 5.104 s−1. High shear rheology is the only way to reach high Peclet number values with nanoparticles in a laminar flow. It was possible to cover a wide range of Peclet number and to have Pe > 1 with diameter in the tens of nanometers range. Our results have demonstrated that an apparent solid volume fraction φa > φ, due to aggregation, was responsible of the increment of viscosity. More important was the demonstration that the shape of the clusters could be modified and that the ratio φa/φ could be lowered by a very high shear rate. Very high shearing rates in microchannels appear to be a way for nanofluids to converge to a well-defined value of viscosities.

The high shear rheology of lithographic emulsions

2000 ◽  
Vol 83 (5) ◽  
pp. 234-239 ◽  
Author(s):  
M. J. Thompson ◽  
M. R. Mackley ◽  
J. A. Nimmo
Keyword(s):  
High Shear ◽  
Shear Rheology ◽  
High Shear Rheology

High shear rheology of paper coating colors - more than just viscosity

1997 ◽  
Vol 20 (8) ◽  
pp. 557-563 ◽  
Author(s):  
Norbert Willenbacher ◽  
Haryutum Hanciogullari ◽  
Hans G. Wagner
Keyword(s):  
High Shear ◽  
Paper Coating ◽  
Shear Rheology ◽  
High Shear Rheology

High shear rheology of shear banding fluids in microchannels

2008 ◽  
Vol 93 (20) ◽  
pp. 204102 ◽  
Author(s):  
Philippe Nghe ◽  
Guillaume Degré ◽  
Patrick Tabeling ◽  
Armand Ajdari
Keyword(s):  
Shear Banding ◽  
High Shear ◽  
Shear Rheology ◽  
High Shear Rheology

A Review of Surface Texture of Tribological Interfaces

2010 ◽  
Vol 37-38 ◽  
pp. 41-45 ◽  
Author(s):  
Zhi Wei Wang ◽  
Mei Wei Chen ◽  
Jian Wei Wu ◽  
Hai Hui Zheng ◽  
Xiao Feng Zheng
Keyword(s):  
Modeling And Simulation ◽  
Surface Texture ◽  
Review Paper ◽  
Tribological Performance ◽  
Current Status ◽  
Comprehensive View ◽  
Lubrication Performance ◽  
Mechanical Components ◽  
Friction And Lubrication

Surface texture of tribological interfaces has the potential to improve friction and lubrication performance of various mechanical components. This review paper emphasizes on the current status of the research of surface texture, including the features, the effects on tribological performance, the forming techniques, and the modeling and simulation of surface texture. It is intended to help readers to gain a more comprehensive view on surface texture of tribological interfaces.

Some Aspects of Nonlinear Behavior in Lubricants Under Extreme Stress

1968 ◽  
Vol 90 (3) ◽  
pp. 549-552
Author(s):  
F. W. Smith
Keyword(s):  
Shear Stress ◽  
Nonlinear Behavior ◽  
High Shear ◽  
High Shear Stress ◽  
Arrhenius Activation Energy ◽  
Flow Process ◽  
Molecular Fluids ◽  
Extreme Stress ◽  
General Basis ◽  
The Continuum

A general basis for discussing nonlinearity in the flow of molecular fluids consists in applying the continuum mechanics of Coleman and Noll to a flow process governed by an Arrhenius activation energy equation. The theory predicts the familiar exponential increase of viscosity with pressure and a decrease in viscosity with high shear stress, and also predicts the existence of “normal stresses” under high shear stress. Schematic calculations are presented for the behavior of a lubricant under extreme stress.

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