Particle structuring under the effect of an uniaxial deformation in soft/hard nanocomposites

A model nanocomposite sample, made of rigid monodisperse spherical inclusions in a deformable matrix, was uniaxially stretched. The displacement field of the particles at the sample surface is analyzed using atomic force microscopy. It is shown that its 2D structure factor presents most of the characteristic features previously described from scattering experiments on similar materials. At the scale of the particles, distortions from affinity are observed. They can be explained by the radial interactions between neighboring inclusions, related to the mechanical confinement of the matrix between particles. At larger scales, remarkable alignments of particles are observed along a direction which is roughly perpendicular to the stretching direction. We show that this effect is found in other soft/hard nanocomposites. It may contribute to the mechanical properties of this class of heterogeneous materials.