Synthesis and Characterization of Graphene-Oxide Reinforced Copper Matrix Composite

Abstract

In this study, eletrolitical copper powder (Cu) was initially mixed with the aqueous solution of graphene oxide (GO); later, the mixture underwent mechanical stirring for 1 h, vacuum filtration, and drying for 42 h. The final concentration of GO in the composite was 0.3%wt. Through scanning electron microscopy (SEM), it was possible to observe the homogeneous dispersion of graphene sheets between copper particles, without the presence of agglomerates. In addition, X-ray diffraction (XRD) of the pure samples and after mixing revealed that there was no oxidation of the copper and the absence of peaks related to other elements, confirming the high purity of the copper used. Still, by XRD, it was possible to analyze that the graphene oxide produced was formed by stacking layers of graphene owing to the appearance of a diffraction peak referring to the plane (002), which was confirmed by Raman spectroscopy performed in GO from the appearance of the 2D bands. Fourier transform infrared spectroscopy (FTIR) allowed the identification of the vibrational spectra referring to the hydroxyl, carbonyl, and epoxy functional groups in GO, confirming that the oxidation process was effective in inserting functional groups in the basal graphical plane. Through the GO thermogravimetric analysis (TGA), it was possible to identify a significant loss of mass of approximately 30% at temperatures below 100 °C; referring to the elimination of water molecules, the most stable functional groups were eliminated at temperatures between 600 °C and 800 °C.

Synthesis and Characterization of Some Graphene Oxide Powders Used as Additives in Hydraulic Mortars

“…They are more prominent in the GO-ZnO powder spectrum and can be associated with the OH group, indicating the hydrophilic character of this powder. The prominent peaks observed at 3365 cm −1 in the GO-Zn spectrum, and at 3363 cm −1 in the GO-ZnO-APTES spectrum can be attributed to the stretching vibrations specific to the OH group and to the N-H stretching vibration, respectively [15,33,39]. The small peaks at 2987 cm −1 and 2900 cm −1 in the GO-ZnO spectrum, which could be also noticed at 2932 cm −1 and 2885 cm −1 in the GO-ZnO-APTES spectrum can be ascribed to the C-H stretching vibration of the alkane group [40].…”

“…The broadband between 3000-3700 cm −1 from the GO-Ag and GO-Ag-APTES spectra can be attributed to the oxygen groups, mainly to the hydroxyl groups located both on the surface and at the edge of GO sheets [24]. The peak at 1621 cm −1 can be assigned to the stretching vibrations of C=O [33], while the one at 1373 cm −1 can be due to the O-H bending vibration [34]. The peak at 1288 cm −1 corresponds to the -C-N bond (characteristic of PVP −1 In the GO-Ag spectrum, the peaks at 3850 cm −1 and at 3733 cm −1 can be assigned to the absorbed water due the stretching vibration of O-H group of carboxyl, alcohol and absorbed water molecules (some also noticed in the GO-Ag-APTES spectrum) [32].…”

Optical and structural properties of graphene oxide-incorporated polyvinylpyrrolidone/copper ternary nanocomposites (PVP/Cu/GO) films

“…These findings suggest that during the film formation process, the Cu nanoparticles may have interacted with the oxygen in the reacting environment, resulting in copper oxidation and the formation of CuO [22]. The lack of a GO diffraction peak in the XRD pattern indicates that the GO sheets are uniformly distributed in the nanocomposites with negligible aggregation [36]. The ob-served sharp peaks indicate that the synthesized films have good crystallinity [37].…”