A density functional study of the structure of tethered chains in a binary mixture

TL;DR

This study uses density functional theory to analyze how various parameters influence the structure of tethered chain layers in a binary mixture, focusing on brush height and component adsorption.

Contribution

It provides a detailed theoretical analysis of tethered chain structures in mixtures, considering interaction parameters and grafting density effects.

Findings

Brush height depends on mixture composition and interaction parameters.

Component adsorption correlates with changes in brush height.

Interactions with substrate significantly influence chain structure.

Abstract

A density functional study of the structure of a layer formed by chain molecules pinned to a solid surface is presented. The chains are modeled as freely joined spheres. Segments and all components interact via Lennard-Jones (12-6) potential. The interactions of fluid molecules with the wall are described by the Lennard-Jones (9-3) potential. We analyze how different parameters of the model affect the dependence of the brush height upon the mixture composition. We consider the effect of grafting density and the parameters characterizing the interactions of fluid molecules with the substrate and with the chains as well as interactions within the mixture. The changes in the brush height correlate with the adsorption of particular components.