Issue 20, 2009

Materials properties of clay nanocomposites: onset of negative Poisson ratio in large-scale molecular dynamics simulation

Abstract

Clay-polymer nanocomposites are a new range of particle-filled composites possessing enhanced mechanical properties. Transmission electron microscopy studies reveal that many single and double clay sheets are bent when immersed in the polymer matrix. To understand the elastic properties of the sheets we investigate their behaviour under compression through molecular dynamics simulations in both aqueous and poly(ethylene oxide) environments. We examine the sheets before and after buckling and find that the elastic properties of the clay sheets are much reduced when buckled in each case. Buckling occurs with only small out-of-plane displacement and we ascertain that any observably bent sheet will have reduced elastic properties. The sheets possess a negative Poisson ratio during buckling, which allows the clay sheet to regain its uncompressed area. We present a simple analytical model which explains the buckling through the competition between in-plane strain energy and out-of-plane displacements. Knowledge of how the elastic properties of the clay sheets change with shape is important for the design of new nanocomposites.

Graphical abstract: Materials properties of clay nanocomposites: onset of negative Poisson ratio in large-scale molecular dynamics simulation

Article information

Article type
Paper
Submitted
16 Apr 2009
Accepted
23 Jun 2009
First published
30 Jul 2009

Soft Matter, 2009,5, 3896-3904

Materials properties of clay nanocomposites: onset of negative Poisson ratio in large-scale molecular dynamics simulation

J. L. Suter and P. V. Coveney, Soft Matter, 2009, 5, 3896 DOI: 10.1039/B907590A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements