Synergistic Multifunctional Optimization of Carbon Fiber/Phenolic Composites via a Hierarchical ZnO @C/Graphene Interface Design

ABSTRACT Carbon fiber reinforced phenolic resin matrix composites (CP) are widely used in the field of electronic devices, which require superior mechanical characteristics, electromagnetic shielding capability, as well as thermal management performance. Optimizing the interfacial architecture offers a viable strategy to simultaneously enhance these key properties. In this work, carbon‐coated ZnO‐graphene (ZnO@C‐GE) was successfully introduced into CP. ZnO@C‐GE constructs a hierarchically porous architecture that synergistically enhances mechanical interlocking (via resin infiltration), electromagnetic wave attenuation (through multi‐scale scattering), and thermal transport (by reducing interfacial voids). Consequently, the tensile strength of ZnO@C‐GE reinforced CP (ZnO@C‐GE‐CP) reaches 168.8 ± 1.7 MPa, representing a 51% enhancement over pure CP. This structural design simultaneously achieves an X‐band electromagnetic interference shielding efficiency (EMI SE) of 43 dB (47% improvement) and thermal conductivity of (8.47 ± 0.11) × 10 −1 W(m·K) −1 (71% increase), attributed to optimized electromagnetic dissipation pathways and reduced interfacial thermal resistance between carbon fibers and resin. These multifunctional advances position ZnO@C‐GE‐CP as a promising candidate for next‐generation electromagnetic shielding.