Production of a cellular structure in carbon nanotube/natural rubber composites revealed by nanomechanical mapping

Composites based on an elastomer, natural rubber (NR), and pristine multiwalled carbon nanotubes (MWCNTs) were prepared using a two-roll mill mixer. The high shear stress produced a homogeneous dispersion of CNTs in the NR matrix. Using an atomic force microscopy nanomechanical mapping technique, the structure and nanoscale mechanical properties of the resulting composites were investigated in term of CNT loading. Topography, elastic modulus, and adhesive energy distribution maps of the materials were obtained at the same point and at the same time in a single scan. Such maps were used to identify and characterize the CNT, NR, and mechanical interfacial regions formed around the CNTs. The mechanical interfacial regions together with the CNTs divide the elastomer matrix into small “cells”. We claim that the cellular structure is produced in the CNTs/NR composites.