Interfacial Synthesis of Polyaniline/Graphene Oxide Composites for Tunable Electromagnetic Wave Absorption

Conventional methods for preparing polyaniline/graphene composites often suffer from issues such as insufficient intermolecular crosslinking and uncontrollable morphological microstructure, leading to long-standing application limitations in the field of electromagnetic wave absorption. This study successfully achieved the controlled composite of polyaniline (PANI) on the surface of graphene oxide (GO) nanosheets using a one-pot interfacial synthesis method. It efficiently exfoliated the expanded layer structure of GO nanosheets and formed a three-dimensional interpenetrating network structure. This structural feature together with the interaction between PANI and GO significantly enhanced the electromagnetic loss capability of the composite material. When the PANI/GO molar ratio was optimized to 3:1, the reflection loss (RL) of the composite reached − 48 dB, and the effective absorption bandwidth (RL ≤ -10 dB) extended to 4.8 GHz. By constructing multiphase heterogeneous interface, the composite achieved ideal impedance matching characteristics and multiple polarization relaxation mechanisms, which were verified by measured input impedance curves and Cole-Cole semicircular curves. When the sample thickness was adjusted within the range of 2.2-5.0 mm, its effective absorption bandwidth could reach 11 GHz (5–16 GHz), demonstrating excellent broadband wave absorption performance. This study provides a reference for designing novel electromagnetic functional composite materials with multi-heterogeneous and hierarchical structures. The tunable nanostructure of the PANI/GO composite prepared via interfacial synthesis holds promise in providing solutions in the development of electromagnetic wave absorption technology.