Research subject: Cellulosic nanomaterials, including cellulose nanocrystals, cellulose nanofibers, and bacterial cellulose, have attracted significant attention as reinforcing agents in epoxy matrices due to their low density, high mechanical strength, suitable elastic modulus, and renewable nature. However, the inherent hydrophilicity of cellulose nanoparticles and their poor interfacial adhesion with epoxy resins impose critical limitations on the mechanical and thermal performance of epoxy nanocomposites. Consequently, surface modification of cellulosic nanomaterials has emerged as a key strategy to enhance interfacial compatibility and improve the overall properties of epoxy-based nanocomposites.
Research approach: This study presents a comprehensive review and analysis of research published between 2023 and 2025, focusing on various surface modification techniques for cellulosic nanomaterials. These techniques include silane treatments, hydrophobic coatings, esterification reactions, and other chemical modifications. The primary objective of these approaches is to reduce the hydrophilicity of cellulose nanofibers, enhance interfacial adhesion between the reinforcing phase and the epoxy matrix, and promote uniform dispersion of nanomaterials within the nanocomposite structure.
Main results: The results of this study demonstrate that surface modification of cellulose nanoparticles significantly enhances their interfacial interactions and dispersion within the epoxy matrix, leading to a noticeable increase in the onset and peak thermal degradation temperatures, a reduction in the thermal degradation rate, and a measurable increase in char residue at elevated temperatures. Improved dispersion and reduced agglomeration of nanofibers result in substantial enhancements in mechanical properties, including tensile strength, elastic modulus, and stiffness, along with improved fracture behavior and effective inhibition of crack propagation. Quantitative analysis indicates that the surface modification method, functional group chemistry and density, nanofiber loading level, and dispersion uniformity play decisive roles in optimizing both thermal stability and mechanical performance. Overall, this work provides a systematic, quantitatively driven engineering framework for the design of durable, high-performance epoxy nanocomposites suitable for high-temperature and demanding industrial applications.