Related papers: Friction of polymers: from PDMS melts to PDMS elas…
\textbf{Background} Hydrogels are crosslinked polymer networks that can absorb and retain a large fraction of liquid. Near a critical sliding velocity, hydrogels pressed against smooth surfaces exhibit time-dependent frictional behavior…
The progressive onset of slip at the wall, which corresponds to a slip length increasing with the solicitation time before reaching a plateau, has been investigated for model viscoelastic polymer solutions, allowing one to vary the longest…
When injected through a contraction, high molecular weight polymer solutions exhibit a sharp increase of apparent viscosity which originates from stretching polymer chains above a critical extension rate. This chain stretching can also…
We investigated the frictional properties of sodium polystyrene sulfonate (NaPSS) brushes in water by frictional force microscopy (FFM). Polyelectrolyte brushes were prepared on silicon wafers by the grafting-to method. The brushes…
We consider the response of an adsorbed polymer that is pulled by an AFM within a simple geometric framework. We separately consider the cases of i) fixed polymer-surface contact point, ii) sticky case where the polymer is peeled off from…
We present an experimental investigation of the non stationary frictional properties of multicontact interfaces between rough elastomers and rough hard glass at low velocities (<= 200 mu m s^{-1}). These systems, for which the deformation…
Nanometer-thick supported lms of polymer melts spontaneously form and spread around sessile droplets that are deposited on oxidized silicon wafers. At steady state, the lms become dense and adopt a uniform thickness which is equal to twice…
We probe the temperature dependence of friction at the interface between a glassy poly(methylmethacrylate) lens and a flat substrate coated with a methyl-terminated self-assembled monolayer. The monolayer exhibits density defects which act…
Using molecular dynamics (MD) we study the dependency of the contact mechanics on the sliding speed when an elastic block (cylinder) with a ${\rm cos} (q_0 x)$ surface height profile is sliding in adhesive contact on a rigid flat…
By solving the equilibrium equations for a polymer in a neutral polymer brush, the degree of interpenetration of two polymer brushes in contact and near contact is calculated. These results are used to calculate values of the force of…
The dynamics of flexible polymer molecules are often assumed to be governed by hydrodynamics of the solvent. However there is considerable evidence that internal dissipation of a polymer contributes as well. Here we investigate the dynamics…
Adhesion control at the interface of two surfaces is crucial in various applications, including the design of micro- and nanodevices such as microfluidic devices, triboelectric nanogenerators, biochips, and electronic sensors. Several…
We present an experimental method allowing to quantify slip at the wall in viscous polymer fluids, based on the observation of the evolution under simple shear flow of a photobleached pattern within a fluorescent labeled polymer melt. This…
We study the possibility for a semi-infinite block of linear viscoelastic material, in homogeneous frictional contact with a non-deformable one, to slide under shear via a periodic set of ``self-healing pulses'', i.e. a set of drifting slip…
Following up a recent paper on grafted sliding polymer layers (Macromolecules 2005, 38, 1434-1441), we investigated the influence of the sliding degree of freedom on the self-assembly of sliding polymeric surfactants that can be obtained by…
There is ample evidence that polymer brushes reduce friction between surfaces. Several industrial applications take advantage of this fact, such as those in plastic bag production, where the brushes act as slip agents; however, the complex…
We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate, and (b) polymer sliding on…
Nonequilibrium molecular dynamics simulations are used to study the shear thinning behavior of immiscible symmetric polymer blends. The phase separated polymers are subjected to a simple shear flow imposed by moving a wall parallel to the…
We report on the frictional behaviour of thin poly(dimethylacrylamide) (PDMA) hydrogels films grafted on glass substrates in sliding contact with a glass spherical probe. Friction experiments are carried out at various velocities and…
We report on the frictional properties of a single contact between a glassy polymer lens and a flat silica substrate covered either by a disordered or by a self-assembled alkylsilane monolayer. We find that, in contrast to common belief,…