Adhesion of Filled Rubber at the Nanoscale.

Adhesion of soft materials to surfaces is significant, considering many industrial applications. Here, we present a computational study for a fundamental understanding of contact and adhesion of filled rubber at the nanoscale. The study includes consideration of the local nanoscale roughness of the filled rubber surface and the underlying substrate. A rubber surface-substrate interaction model is created. Contact area and adhesion energies are determined for different local stress and local temperature values. We performed two different sets of computer simulations. The first set or the homogeneous medium set shows the importance of local surface topography at the nanometer length scales. The second set or the heterogeneous set shows the importance of local elastic properties in conjunction with the local surface topography. The increase in the local temperature softens the rubber surface and increases the contact area and the adhesion energy. If the filler concentration is large, the contact area and adhesion energy abruptly reduce to almost zero in aggregate and agglomerate surface regions with the increase in concentration.