Abstract
Introduction: Graphene is flat monolayer of carbon atoms (one atom thick), covalently bonded to three other atoms in tightly packed two-dimensional (2D) hexagonal single layer stable crystalline honeycomb lattice structure. In this paper, In-situ amine functionalized exfoliated graphene with multiple layers (3-6) with low defect contents and average aspect ratio upto 10 microns (average X and Y dimensions) and thickness upto 2-3 nm (average Z-direction) which have been produced with the combined effort of chemical vapor deposition (CVD) and chemical graphite exfoliation method.
Methods: This paper also focuses on the effect of the reinforcement of amine functionalized multiple graphene layers (AF-MGL) on the mechanical and visco-elastic properties of epoxy composites. AFMGL/ epoxy composites (AF-MGL/EpC) were prepared with graphene fractions ranging from 0.5 to 2.0 wt%. The four different samples were prepared using an amount of graphene as 0.0, 0.5, 1.5, and 2.0. A series of tensile three point bend tests were performed on the different AFMGL/epoxy composites. Optical and scanning electron microscopy (SEM) was used to examine the micro structural features and fractured surfaces of AF-MGL/EpC.
Results: Increased graphene content results in improved tensile strength and the modulus of an epoxy matrix when compared with the pure epoxy matrix. The 1.5 wt% AF-MGL/EpC showed an increase in tensile strength and modulus by 50.2 and 52.8% respectively. However, a shrink was noticed beyond 1.5 wt.% samples of AF-MGL/EpC composite. Moreover, an improvement of 28.8% in the storage modulus was also recorded when compared with epoxy composites.
Conclusion: The effect of the amine functional group on the mechanical and viscoelastic properties was also explored using molecular dynamics (MD) simulations and predicted results were then compared with experimental results.
Keywords: Graphene, functionalization, epoxy, mechanical properties, composites, microscopy.
Graphical Abstract