The growing awareness of socioeconomic and environmental issues and the high percentage of petroleum resources consumed and new environmental regulations have fueled efforts to develop innovative, cutting-edge, environmentally friendly materials with a wide range of applications. Due to environmental and sustainability concerns, the advancement of biocomposites has resulted in tremendous breakthroughs in green materials in this century. Their primary goal is to replace current synthetic petroleum-based composites with natural resources. Materials derived from nonrenewable petroleum-based sources are hazardous and expensive to produce; on the other hand, biocomposites derived from natural sources are biodegradable, recyclable, non-abrasive, and compostable and have properties comparable to synthetic fiber composites. Natural fibers are low-cost, lightweight, biodegradable, renewable, and environmentally friendly alternatives to synthetic fibers like glass and carbon fiber. The long-term viability of natural fiber-based composite materials has led to increased use in various production industries. However, the manufacturing process of natural fiber-based biocomposites is still plagued by some difficulties, such as poor adhesive propensity, moisture absorption, poor fire resistance, low impact strength, and low durability. This review provides a panoramic view to provide insight into different aspects of biocomposites based on natural fibers and polymers in terms of properties and applications, which will pave the way for future biocomposites research in academic and commercial contexts.

Graphene nanoplatelets (GNPs) have received immense attention from the global scientific research community in the 21st century due to their two-dimensional planar structure, high surface area, functionalization abilities, and notable thermal-mechanical-electrical properties. When appropriately integrated into polymer matrices, graphene nanosheets improve the mechanical performance of polymer under static and high-strain rate loading. On the other hand, surface modification of GNPs through functionalization enhances dispersibility and interfacial strength of GNPs/polymer composites. Computational methods for GNPs-based nanocomposites considering micromechanical and multiscale modeling were also developed to predict their thermo-mechanical and electrical properties. These nanocomposite materials have been identified as having a wide range of applications in aerospace, automotive, construction, biomedical, energy storage, sensor, and textiles. In this review paper, recent advances of GNPs/epoxy nanocomposites, including their functionalization processes, characterization techniques, production methods, properties, and potential applications, have been comprehensively explained. Furthermore, it attempts to provide a complete framework for researchers by summarizing and evaluating the extensive literature on these nanocomposite materials.

In this paper, graphene, graphene/matrix, and graphene/fiber nanocomposites, including their synthesis process, fabrication, properties, and potential applications, were reviewed. It was found that several synthesis techniques for nanographene were developed, such as liquid-phase exfoliation and chemical vapor deposition. In addition, some fabrication processes of graphene/matrix and graphene/fiber-based nanocomposites were made, including in-situ polymerization, nanostitching in that single layer nano graphene plate could be interconnected by means of carbon nanotube stitching, resin transfer molding, and vacuum-assisted resin transfer molding. Several properties, including mechanical, thermal, and electrical, on the graphene nanoplatelets materials were summarized in this review paper. It was realized that graphene, graphene/matrix, and graphene/fiber nanocomposites have extraordinary mechanical, thermal, and electrical properties used in advanced engineering applications, including soft robotics, microelectronics, energy storage, biomedical and biosensors as well as textile industry.

This paper presents an experimental investigation of nanocomposites composed of three ratios of epoxy/graphene nanoplatelets (GNPs) by weight. The 0.1, 0.2, and 0.3 wt.% specimens were carefully manufactured, and their mechanical and thermal conductivity properties were examined. The tensile strength and modulus of epoxy/GNPs were enhanced by the large surface area of graphene nanoplatelets, causing crack deflection that created new fracture fronts and friction because of the rough fracture surface. However, the compressive strength was gradually reduced as GNP loading percentages increased. This was probably due to severe plastic yielding on the epoxy, leading to catastrophic axial splitting caused by premature fractures. Furthermore, the highest thermal conductivity was 0.1283 W/m-K, representing a 20.92% improvement over neat epoxy (0.1061 W/m-K) when 0.3 wt.% GNPs were added to the epoxy. This was because of efficient heat propagation in the GNPs due to electron movement through percolative paths. The tensile failure mode in epoxy/GNP nanocomposites showed a few deflected and bifurcated rough cracks and brittle, dimple-like fractures. Contrarily, compressive failure mode in GNP-added epoxy showed plastic flexural buckling and brittle large-axial splitting. The epoxy/GNP nanocomposites were considered a damage-tolerant material.