Shear-induced stretching of adsorbed polymer chains

Soft Matter ◽  
2009 ◽  
Vol 5 (16) ◽  
pp. 3014 ◽  
Author(s):  
Gui-Li He ◽  
René Messina ◽  
Hartmut Löwen ◽  
Anton Kiriy ◽  
Vera Bocharova ◽  
...  
Computation ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 57
Author(s):  
Constantinos J. Revelas ◽  
Aristotelis P. Sgouros ◽  
Apostolos T. Lakkas ◽  
Doros N. Theodorou

In this article, we publish the one-dimensional version of our in-house code, RuSseL, which has been developed to address polymeric interfaces through Self-Consistent Field calculations. RuSseL can be used for a wide variety of systems in planar and spherical geometries, such as free films, cavities, adsorbed polymer films, polymer-grafted surfaces, and nanoparticles in melt and vacuum phases. The code includes a wide variety of functional potentials for the description of solid–polymer interactions, allowing the user to tune the density profiles and the degree of wetting by the polymer melt. Based on the solution of the Edwards diffusion equation, the equilibrium structural properties and thermodynamics of polymer melts in contact with solid or gas surfaces can be described. We have extended the formulation of Schmid to investigate systems comprising polymer chains, which are chemically grafted on the solid surfaces. We present important details concerning the iterative scheme required to equilibrate the self-consistent field and provide a thorough description of the code. This article will serve as a technical reference for our works addressing one-dimensional polymer interphases with Self-Consistent Field theory. It has been prepared as a guide to anyone who wishes to reproduce our calculations. To this end, we discuss the current possibilities of the code, its performance, and some thoughts for future extensions.


1999 ◽  
Vol 35 (1) ◽  
pp. 167-172 ◽  
Author(s):  
Linxi Zhang ◽  
Xianghong Wang ◽  
Haizhu Ma ◽  
Youxing Huang

2015 ◽  
Vol 5 (1) ◽  
pp. 45-49 ◽  
Author(s):  
He Zhu ◽  
Nishad Dhopatkar ◽  
Ali Dhinojwala

The configurational free energy of random flight polymer chains adsorbed by one end onto a plane surface as a function of the distance from a parallel plane surface is expressed to a good approximation in simple analytic form. The result is used to discuss the stabilization of a colloid suspension by adsorbed polymer. According to this theory two types of aggregation of colloid particles may occur. If LI < AS/2π 3 NkT , where l is the link length and L the contour length of a polymer chain, A is the Hamaker constant, N /S is the number of adsorbed polymer chains per unit area and kT is the Boltzman constant multiplied by temperature, the particles adhere closely, but if AS/2π 3 kT < IL < AS/nkT lg 2N a looser association is formed. It is expected that the presence of excluded volume effects would greatly increase the stability against the looser association.


Polymer-stabilized colloid particles are modelled theoretically by plane surfaces on to which polymer chains are adsorbed by one end only. Interactions between segments of the polymer are treated as an excluded volume effect. It is shown that for high surface densities the polymer distribution function exactly satisfies a one dimensional equation which is solved numerically for two values of excluded volume to give the polymer segment density distributions and the free energy of interaction for various separations of the plane surfaces. It is found that a positive value of excluded volume greatly increases the repulsive free energy compared with that for chains with zero excluded volume, particularly at large separation distances of the surfaces. Excluded volume effects must therefore play an important part in the stabilization of colloids by adsorbed polymer.


1996 ◽  
Vol 14 (4) ◽  
pp. 251-257 ◽  
Author(s):  
S. Minko ◽  
I. Luzinov ◽  
I. Evchuk ◽  
S. Voronov

A kinetic method for investigating the adsorbed layer structure of a polymer (the copolymer of styrene and maleic anhydride) on a ZnO powder surface was developed, the method is based on the model of the heterogeneously inhibited polymerization of styrene ‘filled’ with ZnO powder. The polymerization is preceded by an induction period. The length of this period depends on the concentration of inhibiting sites (n) on the surface of ZnO. The adsorbed polymer blocks such inhibiting sites and the induction period decreases. This model was used to estimate n. A peak was observed in the experimental relationship connecting n with the amount adsorbed. This peak was interpreted as the critical concentration for conformation transition brought about by the interaction of the polymer chains at the surface. Below this concentration adsorbed macromolecules are considered as isolated chains at the surface. This state is characterized by the poor mobility of segments.


2015 ◽  
Vol 38 (6) ◽  
Author(s):  
Fabrice Lapique ◽  
Jean Pierre Montfort ◽  
Christophe Derail

2007 ◽  
Vol 1056 ◽  
Author(s):  
Alireza Sarvestani ◽  
Esmaiel Jabbari

ABSTRACTA molecular model is proposed for the dynamics of polymer chains in dilute polymer solutions containing well-dispersed spherical particles. In the presence of short range energetic affinity between the monomers and filler surface, the equilibrium structure of the adsorbed polymer layer is determined by a scaling theory. The viscoelastic response of the suspension is studied by a Maxwell model. It is shown that the solid-like properties of polymer nanocomposites in low frequency regimes could be attributed to the slowdown of the relaxation process of polymer chains. This process is controlled by the monomer-particle frictional interactions, density of the adsorbed polymer chains on the particles surface (controlled by monomer-particle adsorption energy), and volume fraction of the interfacial layer which can be enhanced by reduction of filler size or increasing the filler concentration.


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