Using Self-Consistent-Field Theory to Understand Enhanced Steric Stabilization by Casein-Like Copolymers at Low Surface Coverage in Mixed Protein Layers

2005 ◽  
Vol 6 (6) ◽  
pp. 3018-3029 ◽  
Author(s):  
Emma L. Parkinson ◽  
Rammile Ettelaie ◽  
Eric Dickinson
Keyword(s):  
Field Theory ◽  
Surface Coverage ◽  
Steric Stabilization ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Self Consistent Field Theory ◽  
Mixed Protein

scholarly journals Potential of Mean Force between Bare or Grafted Silica/Polystyrene Surfaces from Self-Consistent Field Theory

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1197
Author(s):  
Aristotelis P. Sgouros ◽  
Constantinos J. Revelas ◽  
Apostolos T. Lakkas ◽  
Doros N. Theodorou
Keyword(s):  
Field Theory ◽  
Molecular Weight ◽  
Potential Of Mean Force ◽  
Steric Stabilization ◽  
Nonbonded Interactions ◽  
Grafting Density ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Self Consistent Field Theory

We investigate single and opposing silica plates, either bare of grafted, in contact with vacuum or melt phases, using self-consistent field theory. Solid–polymer and solid–solid nonbonded interactions are described by means of a Hamaker potential, in conjunction with a ramp potential. The cohesive nonbonded interactions are described by the Sanchez-Lacombe or the Helfand free energy densities. We first build our thermodynamic reference by examining single surfaces, either bare or grafted, under various wetting conditions in terms of the corresponding contact angles, the macroscopic wetting functions (i.e., the work of cohesion, adhesion, spreading and immersion), the interfacial free energies and brush thickness. Subsequently, we derive the potential of mean force (PMF) of two approaching bare plates with melt between them, each time varying the wetting conditions. We then determine the PMF between two grafted silica plates separated by a molten polystyrene film. Allowing the grafting density and the molecular weight of grafted chains to vary between the two plates, we test how asymmetries existing in a real system could affect steric stabilization induced by the grafted chains. Additionally, we derive the PMF between two grafted surfaces in vacuum and determine how the equilibrium distance between the two grafted plates is influenced by their grafting density and the molecular weight of grafted chains. Finally, we provide design rules for the steric stabilization of opposing grafted surfaces (or fine nanoparticles) by taking account of the grafting density, the chain length of the grafted and matrix chains, and the asymmetry among the opposing surfaces.

scholarly journals RuSseL: A Self-Consistent Field Theory Code for Inhomogeneous Polymer Interphases

Computation ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 57
Author(s):  
Constantinos J. Revelas ◽  
Aristotelis P. Sgouros ◽  
Apostolos T. Lakkas ◽  
Doros N. Theodorou
Keyword(s):  
Field Theory ◽  
Polymer Melt ◽  
Polymer Chains ◽  
Solid Polymer ◽  
One Dimensional ◽  
Consistent Field ◽  
Adsorbed Polymer ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Self Consistent Field Theory

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.

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