Sliding Friction between Polymer-brush-bearing Surfaces: Crossover from Brush-brush Interfacial Shear to Polymer-substrate Slip.

2000 ◽  
Vol 651 ◽  
Author(s):  
Jacob Klein
Keyword(s):  
Polymer Brushes ◽  
Shear Force ◽  
Reasonable Agreement ◽  
Sliding Friction ◽  
Polymer Brush ◽  
Interfacial Shear ◽  
Force Response ◽  
Shear Forces ◽  
Stick Slip ◽  
Frictional Forces

AbstractA model is presented for the shear (or frictional) forces Fs between two surfaces a distance D apart as they slide past each other while bearing mutually compressed polymer brushes, on the assumption that sliding takes place at the brush-brush interface. The predictions of the model for the rapid increase in Fs at increasing compressions are in reasonable agreement with experiments on polystyrene brushes immersed in toluene over two decades in Fs. At higher compressions (smaller D) the experimental shear forces increase only slowly, and diverge from the calculated ones which continue to increase rapidly; at the same time the form of the shear force response at these higher compressions reverts from a viscous-like one to a stick-slip behaviour. These observations strongly indicate that at sufficiently high compressions the plane of slip crosses over from the brush-brush interface to the polymer-solid surface.

scholarly journals Determination of the Shear Force at the Balance between Bacterial Attachment and Detachment in Weak-Adherence Systems, Using a Flow Displacement Chamber

2007 ◽  
Vol 74 (3) ◽  
pp. 916-919 ◽  
Author(s):  
M. Reza Nejadnik ◽  
Henny C. van der Mei ◽  
Henk J. Busscher ◽  
Willem Norde
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Shear Force ◽  
Polymer Brush ◽  
Bacterial Attachment ◽  
Adhesion Forces ◽  
Shear Forces ◽  
Flow Displacement

ABSTRACT We introduce a procedure for determining shear forces at the balance between attachment and detachment of bacteria under flow. This procedure can be applied to derive adhesion forces in weak-adherence systems, such as polymer brush coatings, which are currently at the center of attention for their control of bacterial adhesion and biofilm formation.

Sliding Friction Under Extreme Pressures—1

1946 ◽  
Vol 13 (2) ◽  
pp. A148-A156
Author(s):  
S. J. Dokos
Keyword(s):  
Elevated Temperatures ◽  
Sliding Friction ◽  
Normal Load ◽  
Functional Relation ◽  
Sliding Velocity ◽  
Stick Slip ◽  
Wide Range ◽  
Frictional Forces ◽  
Contact Pressures ◽  
Very High

Abstract The program of this investigation on sliding friction is concerned with the evaluation of the frictional forces which occur under very high contact pressures and under varying conditions of speed, temperature, and lubrication. The work presented herein covers the experiments which have been made on sliding friction at normal temperatures. Further experiments on boundary lubrication at normal temperatures and sliding friction at elevated temperatures will be reported in a second paper. This report indicates the behavior of sliding friction when large normal loads react between surfaces in contact over a wide range of sliding velocities. At velocities less than one inch per second magnified photographs of the ruptured surfaces indicate clearly this phenomenon of stick-slip. From the experimental records obtained it was possible to show that a functional relation exists between the following variables: (1) The sliding velocity, (2) the normal load, and, (3) the frequency of stick-slip. New experimental evidence is presented indicating that the natural frequency of the apparatus involved influences the phenomenon of stick-slip.

scholarly journals Shear Resistance Capacity of Interface of Plate-Studs Connection between CFST Column and RC Beam

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Qianqian Wang ◽  
Hua Ma ◽  
Zhenbao Li ◽  
Zhenyun Tang ◽  
Haiyan Chen ◽  
...  
Keyword(s):  
Shear Force ◽  
Concrete Slab ◽  
Theoretical Calculations ◽  
Steel Tube ◽  
Interfacial Shear ◽  
Vertical Shear ◽  
Structural Performance ◽  
Steel Beam ◽  
Rc Beam ◽  
Shear Forces

The combination of a concrete-filled steel tube (CFST) column and reinforced concrete (RC) beam produces a composite structural system that affords good structural performance, functionality, and workability. The effective transmission of moments and shear forces from the beam to the column is key to the full exploitation of the structural performance. The studs of the composite beam transfer the interfacial shear force between the steel beam and the concrete slab, with the web bearing most of the vertical shear force of the steel beam. In this study, the studs and vertical steel plate were welded to facilitate the transfer of the interfacial shear force between the RC beam and CFST column. Six groups of a total of 18 specimens were used to investigate the shear transfer mechanism and failure mode of the plate-studs connection, which was confirmed to effectively transmit the shear forces between the beam and column. The results of theoretical calculations were also observed to be in good agreement with the experimental measurements.

Some Consequences of Coulomb Friction in Modeling Longitudinal Traction

1990 ◽  
Vol 18 (1) ◽  
pp. 13-65 ◽  
Author(s):  
W. W. Klingbeil ◽  
H. W. H. Witt
Keyword(s):  
Shear Force ◽  
Coulomb Friction ◽  
Interfacial Shear ◽  
Force Generation ◽  
Behavior Patterns ◽  
Inflation Pressure ◽  
Friction Law ◽  
The Coefficient Of Friction ◽  
Coulomb Friction Law ◽  
Perfect Adhesion

Abstract A three-component model for a belted radial tire, previously developed by the authors for free rolling without slip, is generalized to include longitudinal forces and deformations associated with driving and braking. Surface tractions at the tire-road interface are governed by a Coulomb friction law in which the coefficient of friction is assumed to be constant. After a brief review of the model, the mechanism of interfacial shear force generation is delineated and explored under traction with perfect adhesion. Addition of the friction law then leads to the inception of slide zones, which propagate through the footprint with increasing severity of maneuvers. Different behavior patterns under driving and braking are emphasized, with comparisons being given of sliding displacements, sliding velocities, and frictional work at the tire-road interface. As a further application of the model, the effect of friction coefficient and of test variables such as load, deflection, and inflation pressure on braking stiffness are computed and compared to analogous predictions on the braking spring rate.

The Effect of Ball Pad Metallurgy and Ball Composition on Solder Ball Integrity of Plastic Ball Grid Array Packages

1998 ◽  
Author(s):  
C.H. Zhong ◽  
Sung Yi
Keyword(s):  
Failure Mode ◽  
Barrier Layer ◽  
Shear Force ◽  
Solder Ball ◽  
Ball Grid Array ◽  
Reliability Test ◽  
Shear Forces ◽  
Ball Shear ◽  
Plastic Ball ◽  
Plastic Ball Grid Array

Abstract Ball shear forces of plastic ball grid array (PBGA) packages are found to decrease after reliability test. Packages with different ball pad metallurgy form different intermetallic compounds (IMC) thus ball shear forces and failure modes are different. The characteristic and dynamic process of IMC formed are decided by ball pad metallurgy which includes Ni barrier layer and Au layer thickness. Solder ball composition also affects IMC formation dynamic process. There is basically no difference in ball shear force and failure mode for packages with different under ball pad metallurgy before reliability test. However shear force decreased and failure mode changed after reliability test, especially when packages exposed to high temperature. Major difference in ball shear force and failure mode was found for ball pad metallurgy of Ni barrier layer including Ni-P, pure Ni and Ni-Co. Solder ball composition was found to affect the IMC formation rate.

Frictional Behavior of Textile Fabrics Part I: Sliding Phenomena of Fabrics on Metallic and Polymeric Solid Surfaces

1997 ◽  
Vol 67 (11) ◽  
pp. 793-802 ◽  
Author(s):  
Luis Virto ◽  
Arun Naik
Keyword(s):  
Sliding Friction ◽  
Solid Material ◽  
Solid Surfaces ◽  
Friction Behavior ◽  
Stick Slip ◽  
Compression Load ◽  
Physical Description ◽  
Frictional Behavior ◽  
Textile Fabrics ◽  
Polymeric Solid

This paper presents experimental results on the sliding of fabrics on metallic and polymeric solid surfaces, showing the influence of the compression load at the solid-fabric interface and the nature of the solid material, and the effect of sliding speed on the sliding friction coefficient. At the same time, a physical description of the sliding phenomenon is given. On the basis of these observations, a theoretical approach is developed to explain the sliding friction behavior of fabrics on solid surfaces. Part II will deal with the waving and stick-slip phenomena, which are evident in the sliding process under certain conditions.

Polymer Brushes: High-Resolution, Large-Area, Serial Fabrication of 3D Polymer Brush Structures by Parallel Dip-Pen Nanodisplacement Lithography (Small 23/2012)

Small ◽  
2012 ◽  
Vol 8 (23) ◽  
pp. 3567-3567 ◽  
Author(s):  
Xuechang Zhou ◽  
Zhilu Liu ◽  
Zhuang Xie ◽  
Xuqing Liu ◽  
Zijian Zheng
Keyword(s):  
High Resolution ◽  
Polymer Brushes ◽  
Polymer Brush ◽  
Large Area

scholarly journals Theory of Lubrication due to Poly-Electrolyte Polymer Brushes

2007 ◽  
Vol 1049 ◽  
Author(s):  
Jeffrey B. Sokoloff
Keyword(s):  
Field Theory ◽  
Osmotic Pressure ◽  
Dry Friction ◽  
Polymer Brushes ◽  
Mean Field Theory ◽  
Polymer Brush ◽  
Mean Field ◽  
The Mean ◽  
Coated Surfaces

AbstractIt is shown using a method based on the mean field theory of Miklavic Marcelja that it should be possible for osmotic pressure due to the counterions associated with the two polyelectrolyte polymer brush coated surfaces to support a reasonable load (i.e., about 105 Pa) with the brushes held sufficiently far apart to prevent entanglement of polymers belonging to the two brushes, thus avoiding what is likely to be the dominant mechanisms for static and dry friction.

The structure of polymer brushes near the transition from dilute to dense systems. A computer simulation study

Soft Matter ◽  
2021 ◽  
Author(s):  
Piotr Polanowski ◽  
Andrzej Sikorski
Keyword(s):  
Computer Simulation ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Simulation Study ◽  
Polymer Brushes ◽  
Polymer Brush ◽  
Coarse Grained ◽  
Computer Simulation Study ◽  
Coarse Grained Model ◽  
Cooperative Motion

Monodisperse polymer brushes were studied by means of Monte Carlo simulations. A coarse-grained model of a polymer brush was designed in order and the Cooperative Motion Algorithm was employed to...

Evolution and Applications of Polymer Brush Hypersurface Photolithography

2021 ◽  
Author(s):  
Daniel Valles ◽  
Yerzhan Zholdassov ◽  
Adam Braunschweig
Keyword(s):  
Polymer Brushes ◽  
Polymer Brush ◽  
Printing Method

Hypersurface Photolithography (HP) is a printing method for fabricating structures and patterns composed of polymer brushes, and can be used to create patterns with complex topologies or for rapidly accelerating...

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