Multifunctional hybrid composite for structural-electromagnetic applications: a comparative study of rGO-ferrite and graphite-ferrite reinforcements in glass fiber/epoxy

This study introduces a novel, comprehensive evaluation of hybrid composites built on glass fiber-reinforced epoxy, incorporating ferrite-based hybrid fillers: NiFe2O4/CoFe2O4 dispersed in reduced graphene oxide (rGO), benchmarked against graphite matrices. The ferrites were initially synthesized via chemical solution route, further NiFe2O4/CoFe2O4-rGO was prepared using a solvothermal reduction method. Microstructural analysis confirmed the successful deposition of spinel-structure ferrites on rGO. The rGO-based hybrid composites suggested to be superior multifunctional performance across dielectric, mechanical, and dynamic properties. Dielectric impedance spectroscopy revealed a lower dielectric loss (tandelta < 0.07) and a higher Q factors (>24) for rGO systems, signifying superior dielectric efficiency. While graphite systems showed higher overall electromagnetic interference (EMI) shielding due to absorption, the rGO-ferrite systems maintained low reflection and effective impedance matching across the X-band. Crucially, dynamic analysis and tensile testing confirmed the structural advantages of the rGO hybrids. The rGO composites exhibited improved stiffness and vibration resistance with higher natural frequencies and lower damping. Specifically, CoFe2O4-rGO composites achieved the highest mechanical strength 138.37 MPa and ductility, supported by enhanced interfacial adhesion shown in SEM fractography. These findings underscore the multifunctional advantage of rGO-based hybrid ferrite composites, establishing them as compelling candidates for advanced structural, dielectric, and EMI shielding applications that demand a refined balance of mechanical integrity, electrical performance, and vibrational stability.