Reduced Graphene Oxide-Induced Polyethylene Crystallization in Solution and Nanocomposites

Abstract

We report epitaxial crystallization of polyethylene (PE) on reduced graphene oxide (RGO) nanosheets via a controlled solution crystallization method. Polarized light microscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were used to investigate morphology of RGO-induced PE crystals. The PE edge-on crystals formed from randomly distributed rodlike nuclei on the basal plane of RGO nanosheets and further grew into larger lamellae with an average dimension of a few hundreds of nanometers. Selected area electron diffraction (SAED) pattern revealed that the c-axis of polymer chain is parallel to the basal plane of the RGO nanosheets. PE/RGO nanocomposites (PGNs) with different RGO loadings were fabricated through solution crystallization/precipitation using the PE-decorated RGO hybrid as the precursor. Both nonisothermal and isothermal crystallization behaviors of PGNs were studied using differential scanning calorimetry (DSC). Crystallization kinetics of PGNs was substantially accelerated in the presence of 2D RGO nanosheets. Dramatic improvement of thermal stability was found for PE in the presence of a small amount of RGO nanosheets.

Synthesis, characterization and crystallization kinetics of nanocomposites prepared by in situ polymerization of ethylene and graphene

“…Cheng et al reported a strong nucleation effect of reduced graphene oxide (rGO) and polyethylene nanocomposites. Contrary to our results, the authors observed a decrease in the value of n, but this decrease was attributed to the growth of numerous spherulites at or near the rGO surface, which impinge with each other at early stages of crystallization and form a quasi-2D layer of spherulites [25]. Similarly, the nucleation effect of graphene and functionalized graphene has been reported for many other polymers, e.g., polypropylene [34,35] and polyphenylene sulfide [36].…”

“…The insignificant change in the crystalline melting temperature indicates that the reduction in crystallinity may be due to restriction of chain movements by graphene. Shan et al also reported insignificant changes in T m for reduced graphene oxide and polyethylene nanocomposites [25]. The chain heterogeneity and microstructure can be analyzed by CRYSTAF.…”

The Influence of Epitaxial Crystallization on the Mechanical Properties of Polyamide 66/Reduced Graphene Oxide Nanocomposite Injection Bar

“…The orientation of crystals in PCL/RGO nanocomposites obviously enhances, and its mechanical property significantly improves. Analogously, another high crystallization polyethylene (PE) can epitaxially grow on the interface of laminated RGO and the mechanical properties of PE/RGO nanocomposite were improved [33,34]. However, the influence of epitaxial crystallization in a semi-crystalline polymer with H-bond and RGO nanocomposites is rarely mentioned in industrial production modeling.…”

Novel stearic acid/graphene core–shell composite microcapsule as a phase change material exhibiting high shape stability and performance

“…For a solid-liquid PCM utilizing crystallization-melting, the latent heat depends on the crystallinity of the active material. The crystallization of a matrix material can be accelerated by the presence of heterogeneous fillers because of their nucleating effect [36]. Whereas the structural characteristics of the fillers or the strong interactions between the fillers and the matrix material at the interface can inhibit the crystallization of the matrix material [37,38].…”