Influence of chain stiffness, grafting density and normal load on the tribological and structural behavior of polymer brushes: a nonequilibrium-molecular-dynamics study

Singh, M. K., Ilg, P. ORCID: https://orcid.org/0000-0002-7518-5543, Espinosa-Marzal, R. M., Spencer, N. D. and Kroger, M. (2016) Influence of chain stiffness, grafting density and normal load on the tribological and structural behavior of polymer brushes: a nonequilibrium-molecular-dynamics study. Polymers, 8 (7). 254. ISSN 2073-4360 doi: 10.3390/polym8070254

Abstract/Summary

We have performed coarse-grained molecular-dynamics simulations on both flexible and semiflexible multi-bead-spring model polymer brushes in the presence of explicit solvent particles, to explore their tribological and structural behaviors. The effect of stiffness and tethering density on equilibrium-brush height is seen to be well reproduced within a Flory-type theory. After discussing the equilibrium behavior of the model brushes, we first study the shearing behavior of flexible chains at different grafting densities covering brush and mushroom regimes. Next, we focus on the effect of chain stiffness on the tribological behavior of polymer brushes. The tribological properties are interpreted by means of the simultaneously recorded density profiles. We find that the friction coefficient decreases with increasing persistence length, both in velocity and separation-dependency studies, over the stiffness range explored in this work.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/66143
Identification Number/DOI	10.3390/polym8070254
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Mathematics and Statistics
Publisher	MDPI
Download/View statistics	View download statistics for this item