Effects of graphene, alumina, and their hybrid on dynamic mechanical behavior of epoxy-based nanocomposites

Graphene has excellent mechanical and thermal properties, while alumina has inexpensive and strong thermal stability, making it ideal for electronic packaging applications. The current work examines the effects of modest loadings of reduced graphene oxide (rGO), alumina (Ala), and their hybrids on the dynamic mechanical characteristics and thermal transitions of epoxy-based nanocomposites. The rGO was made using a modified Hummers’ method. Alumina nanoparticles were used as received. Various epoxy nanocomposite samples with 1 wt% of rGO, 1 wt% of Ala, and 0.5 wt% each of rGO and Ala were created. Then, Raman spectroscopy, XRD, FTIR, XPS, TEM, AFM, and SEM were used to analyze the fillers and their hybrid and epoxy-based nanocomposites. Dynamic mechanical analysis was used to examine the hybrid epoxy-based nanocomposites’ dynamic mechanical behavior. It has been demonstrated that different epoxy nanocomposites with 1 wt% Ala and 1 wt% rGO have higher elastic moduli than those with 0.5 wt% rGO and 0.5 wt% Ala. The rGO-Ala hybrid nanocomposites, on the other hand, exhibit moderate damping and glass transition temperatures. The reason for that may be because Ala filler increases the contact area between the rGO sheets and serves as a bridge between the two fillers, decreasing the resistance to deformation. This may enhance the possibility that these stress concentrations will weaken the composites.

Study on Thermal Conductivity of P-Phenylenediamine Modified Graphene/Epoxy Composites

Thermal management has become an important requirement for many types of electrical equipment due to the development of integrated circuits. In this study, modified and reduced graphene fillers were synthesized in two steps, and then epoxy resin was filled through the evaporation of the solvent. The interfacial thermal resistance between the filler and matrix material was lowered by including amino groups to improve graphene compatibility in the epoxy resin. Furthermore, the reduction procedure was shown to have the potential to fix graphene oxide flaws, thereby improving thermal stability, electrical conductivity, and thermal conductivity of the composites. As a result, the thermal conductivity of the composite reached 1.7 W/mK, which is 750% higher than that of pure epoxy resin, and it was still insulated.

Mixed sp2-sp3 Nanocarbon Materials: A Status Quo Review

Carbon nanomaterials with a different character of the chemical bond-graphene (sp2) and nanodiamond (sp3)-are the building bricks for a new class of all-carbon hybrid nanomaterials, where the two different carbon networks with sp3 and sp2 hybridization coexist, interacting and even transforming into one another. The extraordinary physiochemical properties defined by the unique electronic band structure of the two border nanoallotropes ensure the immense application potential and versatility of these all-carbon nanomaterials. The review summarizes the status quo of sp2 - sp3 nanomaterials, including graphene/graphene-oxide-nanodiamond composites and hybrids, graphene/graphene-oxide-diamond heterojunctions, and other sp2-sp3 nanocarbon hybrids for sensing, electronic, and other emergent applications. Novel sp2-sp3 transitional nanocarbon phases and architectures are also discussed. Furthermore, the two-way sp2 (graphene) to sp3 (diamond surface and nanodiamond) transformations at the nanoscale, essential for innovative fabrication, and stability and chemical reactivity assessment are discussed based on extensive theoretical, computational and experimental studies.

Epoxy Nanocomposites Filled with Carbon Nanoparticles

Over the past decades, the development of high performance lightweight polymer nanocomposites and, in particular, of epoxy nanocomposites has become one the greatest challenges in material science. The ultimate goal of epoxy nanocomposites is to extrapolate the exceptional intrinsic properties of the nanoparticles to the bulk matrix. However, in spite of the efforts, this objective is still to be attained at commercially attractive scales. Key aspects to achieve this are ultimately the full understanding of network structure, the dispersion degree of the nanoparticles, the interfacial adhesion at the phase boundaries and the control of the localization and orientation of the nanoparticles in the epoxy system. In this Personal Account, we critically discuss the state of the art and evaluate the strategies to overcome these barriers.