Fiber matrix interfaces driven mechanisms for enhanced electromagnetic wave attenuation in composite materials

Electromagnetic interference is a persistent challenge for modern electronic systems, as it deteriorates signal reliability and complicates compliance with electromagnetic compatibility standards, especially in compact devices. Conventional shielding materials, although functional, often display shortcomings such as excessive mass, tendency to oxidize, rigidity, high manufacturing cost, and poor environmental adaptability. To overcome these issues, a sustainable and lightweight composite was engineered using chemically treated Moringa oleifera fibers as reinforcement combined with reduced graphene oxide dispersed in a resin matrix, referred to as rGEPMF. Structural and thermal analyses confirmed strong bonding between phases and uniform distribution of nanofillers. The numerous interfaces created within the hybrid structure intensified interfacial polarization, promoting additional scattering and absorption of incoming electromagnetic waves. Tests performed in the gigahertz range with a vector network analyzer revealed shielding effectiveness close to 20 dB, arising from a balance of absorption and reflection mechanisms. The material also exhibited electrical conductivity of 0.60 S/m, attenuation coefficient of 50 dB/m, skin depth of 0.0064 mm and improved impedance compatibility compared to the variant without rGO. These enhancements are mainly due to the establishment of a conductive network and efficient interface-driven polarization, enabling significant dissipation of electromagnetic energy through dielectric and conductive losses.