Influence of graphene oxide additives on the filler structure and the physical and mechanical properties of carbon-graphite nanocomposite

In this work, the influence of graphene oxide (GO) additives on the structure and morphology of graphite filler, as well as the strength characteristics of final carbon-graphite composites, is investigated. The formulation of prototype charge samples was selected using the mathematical method of experiment planning and the Hartley plan. The granulometric composition of the initial and modified charge samples, along with their adsorption capacity with respect to pitch, was determined. Scanning electron microscopy, Raman spectroscopy, XRD analysis, vibration density measurements, and specific surface area analysis (via BET) were used to evaluate the structure and morphology of the filler particles. It was found that when 0.9 wt. % GO is added to the filler composition, a denser grain structure with fewer voids is formed. At the same time, the specific surface area decreases by a factor of 3.6, while the sorption capacity for pitch, on the contrary, increases by a factor of 2.7, indicating a change in the chemical composition of the filler particle surfaces. According to Raman spectroscopy data, the modified charge samples exhibit a higher D/G ratio, the presence of functional groups on the particle surface, and a predominance of edge defects. Physical and mechanical testing of the samples after firing revealed that the introduction of 0.9 wt. % graphene oxide increases the compressive strength from 35.5 to 97.5 MPa. These results are significant for the development of new composite materials for tribotechnical applications.