Origins of elastic properties in ordered nanocomposites

TL;DR

This paper predicts how adding spherical nanoparticles to lamellar diblock copolymer melts affects their elastic properties, decreasing tensile modulus but increasing shear modulus in single domains.

Contribution

It introduces a theoretical model explaining the impact of nanoparticle swelling and displacement on the elastic moduli of nanocomposites.

Findings

Tensile modulus decreases with nanoparticle addition.

Shear modulus increases significantly in single domains.

Nanoparticle swelling influences elastic behavior.

Abstract

We predict a diblock copolymer melt in the lamellar phase with added spherical nanoparticles that have an affinity for one block to have a lower tensile modulus than a pure diblock copolymer system. This weakening is due to the swelling of the lamellar domain by nanoparticles and the displacement of polymer by elastically inert fillers. Despite the overall decrease in the tensile modulus of a polydomain sample, the shear modulus for a single domain increases dramatically.