Fabrication of Graphene Nanoplatelet/Epoxy Nanocomposites for Lightweight and High‐Strength Structural Applications

Abstract

Graphene nanoplatelets (GNPs), the most important mass‐produced graphene, are fabricated as a mechanical reinforcement for epoxy matrix nanocomposites. Current performance of GNPs as a reinforcing filler is limited by their agglomeration and weak interfacial interaction with certain polymer matrices. Herein, an approach to produce noncovalently functionalized GNPs (F‐GNPs) is reported that can be extended to the industrial level of mass production. The one‐step functionalization process uses melamine, a low‐cost chemical, to improve the interfacial adhesion and dispersion in an epoxy matrix. The mechanical properties of nanocomposites prepared with the F‐GNP flakes are much better (94.3% and 35.3% enhancements in Young's modulus and tensile strength, respectively) than those of the unfilled pure epoxy. Experimental data are analyzed using the Halpin–Tsai model. The fabrication process developed in this paper provides a strategy to use GNPs at the industrial level in lightweight and high‐strength structural applications.

Electrical Conductivity and Compressive Strength of Cement Paste with Multiwalled Carbon Nanotubes and Graphene Nanoplatelets

“…Although some studies showed that excessive functionalization treatment adversely affected the strength of cementitious composites by causing physical damage to the surface of the CBNs, no such defects were found in this study [36]. This may have been because the MWCNTs and GNPs were noncovalently functionalized through the aromatic ring in melamine via π-π interactions that did not change the surfaces, unlike covalent functionalization [30]. Figure 6 shows the effect of the hybridizations of MWCNTs and GNPs on the compressive strength.…”

“…This study investigated the effect of securing dispersibility through functionalization on conductivity. The MWCNTs and GNPs were noncovalent functionalized using the process proposed by Kim et al [30]. The functionalization process performed in this study is shown in Figure 1.…”

“…Kim et al [30] proposed a method for the noncovalent functionalization of GNPs using a ball-milling process with melamine to improve their interfacial adhesion and dispersion in an epoxy matrix. In this study, the method suggested by Kim et al was used to homogeneously disperse the MWCNT or GNP in a cement paste matrix and compared this approach with ultrasonication, which is the most common dispersing method [30]. Most of the existing studies investigated the properties of cementitious composites by individually incorporating MWCNTs or GNPs.…”

Fabrication of Eco-Friendly Graphene Nanoplatelet Electrode for Electropolishing and Its Properties

“…We used a one-step ball milling process for the melamine functionalization process. The ball milling process for graphene functionalization has advantages on mass production for defect-free graphenes [11]. The functionalization of GNPs was verified by spectroscopic analysis.…”

Graphene nanoplatelets/epoxy nanocomposites: A review on functionalization, characterization techniques, properties, and applications

“…62 Non-covalent functionalization is a suitable technique because it does not modify the edges of GNPs. For this reason, it completely preserves the surface and has no effect on the ultimate material structure 63 and makes it more compatible than covalent functionalization. Although this functionalization process preserves graphene's original structure, the interactions between functionalities and the graphene surface are relatively weak.…”