Changes in the structure of tethered chain molecules as predicted by density functional approach

TL;DR

This study uses density functional theory to analyze how tethered chain molecules' structure changes with chain length, surface density, and temperature, revealing novel effects like layer height minima and temperature-induced height decreases.

Contribution

It introduces a density functional approach to predict new phenomena in tethered chain layers, including height minima and temperature effects not previously observed.

Findings

Layer height can reach a minimum at certain conditions.

Layer height may decrease with increasing temperature.

New effects not seen in prior studies.

Abstract

We use a version of the density functional theory to study the changes in the height of the tethered layer of chains built of jointed spherical segments with the change of the length and surface density of chains. For the model in which the interactions between segments and solvent molecules are the same as between solvent molecules we have discovered two effects that have not been observed in previous studies. Under certain conditions and for low surface concentrations of the chains, the height of the pinned layer may attain a minimum. Moreover, for some systems we observe that when the temperature increases, the height of the layer of chains may decrease.