Epitaxial Crystallization of Poly(ε-caprolactone) on Reduced Graphene Oxide at a Low Shear Rate by In Situ SAXS/WAXD Methods

Abstract

The interfacial interaction between polymers and reinforcements has a positive effect on the properties of polymer nanocomposites, and a further study on the evolution of this interfacial interaction under a shear field is conducive to reasonable regulation of the properties of polymer nanocomposites. For this purpose, epitaxial crystallization of poly(ε-caprolactone) (PCL) on reduced graphene oxide (RGO) is investigated by shearing at the shear rate of 3 s −1 by in situ synchrotron radiation. In situ two-dimensional small-angle X-ray scattering (2D SAXS) results suggest that the imposed shear field promotes the orientation of the polymer chains, resulting in the formation of a large periodic structure of PCL on the RGO surface. In addition, higher shear temperatures facilitate the conformational adjustment of the PCL molecular chain on RGO at the shear rate of 3 s −1 , resulting in the formation of thicker lamellae. In situ two-dimensional wide-angle X-ray diffraction (2D WAXD) results show that shear enhances the crystallinity of the PCL/RGO nanocomposite and promotes the oriented growth of epitaxial and bulk crystals. The current findings can improve the understanding of the structural evolution behavior of PCL/RGO nanocomposites after shear and especially enhance dramatically our understanding of the underlying mechanism of influence of shear on interfacial epitaxial crystallization in polymer/graphene nanocomposite systems.

The Impact of Graphene Oxide on Polycaprolactone PCL Surfaces: Antimicrobial Activity and Osteogenic Differentiation of Mesenchymal Stem Cell

“…In recent years, a large body of investigation has been dealing with nanofiller as a reinforcement to improve or introduce new properties at the nano-and macro-scale. Graphene-related materials, including graphene oxide (GO), reduced graphene oxide (rGO), or graphene nanoplates, were embedded in PCL to enhance the crystallization and orientation of polymer matrix or to make PCL conductive [8][9][10].…”