Nanomechanical Property Analysis of Polymer Surfaces by Atomic Force Microscopy

Abstract

Atomic force microscopy (AFM) is now recognized as one of the major tools to investigate the structural and mechanical properties of polymer surfaces. We were particularly interested in information obtained from force-distance curves of rubbery or melt state samples. By analyzing the force-distance curves, the sample deformation by the force applied on the surface and the resultant real height free from sample deformation were estimated. The force-distance curves also gave us Young's modulus by analyzing curves with Hertz theory. Thus, when force-distance curve measurements were performed on every point of the sample (force-volume measurements), we could obtain a sample deformation image, a real height image, and a Young's modulus image simultaneously. We demonstrated the application of this method on the blend of unvulcanized natural rubber and ethylene-propylene diene elastmer.