Interfacial energy characterization in hydroxyapatite-modified natural fiber reinforced composite: experimental measurement and computational modeling

Natural fiber-reinforced composites are increasingly recognized for their sustainability and cost-effectiveness, making them popular in a wide range of applications. To fully unlock their potential in mechanical performance, nanomaterials are explicitly incorporated to enhance the fiber–matrix interface. One of the key factors in improving the interface is the fiber-nanomaterial surface energy, which governs fiber adhesion and stress transfer between the fibers and the matrix. Despite its importance, characterizing surface energy at the interface is challenging due to the need for specialized instrumentation and the complexity of nanoscale interactions. This further hinders the development of computational models that target the critical interfacial region. This study presents an experimentation-facilitated computational modeling approach to investigate adhesion at the fiber–nanomaterial interface. Hydroxyapatite nanocrystals were synthesized in situ on jute fibers using a low-temperature hydrothermal method, and adhesion was experimentally characterized through nanoscratch tests, yielding quantitative insights into the fiber-nanomaterial adhesion. Sensitivity analysis indicated that surface energy is more critical than elastic properties in determining interfacial adhesion. This integrated approach provides a robust framework for designing high-performance composite interfaces.