Surface Segregation of Cyclic Chains in Binary Melts of Thin Polymer Films: The Influence of Constituent Concentration.

Francis Gaitho,Genene Mola,Mesfin Tsige,Giuseppe Pellicane

doi:10.3390/polym10030324

Francis Gaitho, Genene Mola + Show 2 more

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https://doi.org/10.3390/polym10030324

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Abstract

We carry out extensive molecular dynamics simulations of thin films of bead-spring models of binary mixtures composed of cyclic and linear polymer chains. We study the equilibrium behavior of the polymer chains for two very different chain lengths, which resemble short (10-mers) and long (100-mers) chains, at different concentrations of the binary mixture. We clearly show how the concentration variable affects the enrichment of either of the two polymer species at the interface, and also how the chain length influences this process.

Highlights

The dynamics and phase separation of binary polymer blends is in general dependent on the concentration of one of the two molecular species in the medium
The main aim of this paper is to fill the gap of knowledge regarding the effect of concentration on interfacial properties of cyclic-linear polymer mixtures exposed to vacuum, by performing extensive molecular dynamics (MD) simulations
We found that cyclic chains are more enhanced at the interface, but the concentration of cyclic chains becomes less enhanced upon increase of their concentration

Summary

Introduction

The dynamics and phase separation of binary polymer blends is in general dependent on the concentration of one of the two molecular species in the medium. Gaining microscopic insight into how the change in concentration affects interfacial properties is necessary to predict mechanical and electrical behavior of polymeric materials, as well as to control many processes of industrial interest, including chemisorption, oxidation, and corrosion [10,11]. Several computational [12,13,14,15,16,17,18,19,20] and experimental [21,22,23,24,25] investigations of interfacial properties of thin films of binary polymer blends have been reported in recent literature. One system that has been subject of intense study is a blend of linear and cyclic polymers, where the strategy of mixing up a closed-loop

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