Surface force spectroscopy of elastomeric nanoscale films

We studied nanomechanical properties for a series of ultrathin films of ela stomeric materials from polyisoprene rubbers and triblock styrene-butadiene -styrene copolymer, SEES. As we observed, the Hertzian approximation for el astic mechanical deformation of double layer films can be used for the anal ysis of force-distance data at modest indentation depths and film thickness higher than 3 nm. For thinner films, the influence of solid substrate beco mes very significant. On the other hand, the applicability of the Hertzian approximation is limited by the rate dependent elastomeric deformation. We demonstrated that Johnson modification of the contact mechanics model that includes a viscoelastic contribution could be utilized to obtain reasonable fitting of loading data for elastomeric materials.