Investigation of a dilute polymer solution in confined geometries

TL;DR

This paper reviews theoretical, numerical, and experimental studies on the behavior of dilute polymer solutions and colloids confined in restricted geometries, highlighting complex physical effects and practical applications.

Contribution

It applies the massive field theory approach in three dimensions to analyze polymer and colloid behavior in confined spaces, providing new insights and quantitative results.

Findings

Polymer chains exhibit nontrivial behavior under confinement.

Depletion interactions depend on surface properties and geometry.

Results align with previous theories, simulations, and experiments.

Abstract

The paper presents a short overview of the theoretical, numerical and experimental works on the critical behavior of a dilute polymer solution of long-flexible polymer chains confined in semi-infinite space restricted by a surface or in a slit geometry of two parallel walls with different adsorbing or repelling properties in respect for polymers as well as in a solution of mesoscopic spherical colloidal particles of one sort or two different sorts. We discuss the application of the massive field theory approach in a fixed space dimensions d=3 up to one loop order for such topics as:(a) the investigation of the elastic properties of real polymer chain immersed in a good solvent and anchored by one end to the surface and with other end being under tension of the external applied force;(b) the calculation of the monomer density profiles, the depletion interaction potentials and the depletion forces which arise in a dilute polymer solution immersed in confined geometries, like slit of two parallel walls with different adsorbing or repelling properties in respect for polymers or in the polymer-colloid mixtures with mesoscopic spherical colloidal particles of one sort or two different sorts. The presented results give possibility better to understand the complexity of physical effects arising from confinement and indicate about the interesting and nontrivial behavior of linear polymer chains in confined geometries and are in good qualitative and quantitative agreement with previous theoretical investigations, results of DFT, MC simulations and experimental data based on the AFM and TIRM. Besides, the obtained results have important practical applications for better understanding of the elastic properties of the individual macromolecules, networks, gels and brush layers as well as indicate about possibility of application in production of new types of nano- and micro-electromechanical devices.