Published online by Cambridge University Press: 15 October 2013
Atomic force microscopy (AFM) and Raman spectroscopy were used to characterize the morphology and the local mechanical properties of polypropylene-based graphene nanocomposites. Amplitude Modulated AFM was used to perform phase angle measurements to estimate the loss tangent, along with the local elastic modulus of the nanocomposite’s surface as a function of graphene content. We have observed an increasing trend in phase angle as the graphene content increased. We also identified wrinkled graphene flakes embedded in the polymer matrix. The graphene corrugation and mismatched strain between polymer and graphene sheets show a variation in the phase angle that is corroborated with Raman measurements. Mechanically exfoliated graphene on SiO2 was characterized as a baseline to understand the effect of graphene wrinkles compared to graphene surfaces on phase angle. The Raman results revealed that there are changes in the crystalline morphology of the polymer with the addition of graphene.