Construction of sub‐micron eccentric Ag@PANI particles by interface and redox potential engineering

Benefitting from the tunable heterogeneous interface and electronic interaction, metal-polymer-based hybrid composites have attracted wide attention. It is highly desired to develop advanced synthesis methodology and understand the structure-performance relationship. Herein, with the aniline oligomer as the key enabler, we resolve the inferior dynamics issue in the Ag+-aniline reaction system, and successfully fabricate a sub-micron anisotropic eccentric Ag@polyaniline (PANI) particle (an average size up to 340 nm) at room temperature. We demonstrate the synergy mechanism of polyvinyl pyrrolidone and in-situ generated PANI for modifying the dynamic reaction interface. We further clarify the H+ concentration and the surfactant types serve as main descriptors to tune the reaction dynamics. Besides, by applying other aniline oligomers, a series of similar eccentric structures can also be obtained, indicative of the good applicability of our strategy. Such a sub-micron eccentric structure furnishes the Ag@PANI composites with sound performance for microwave absorption, as demonstrated by a minimum reflection loss (RL) value of −35 dB with an effective absorption bandwidth of 3.7 GHz. This study provides an inspiring scope/concept of eccentric microstructure engineering for better meeting the demands in the high-tech military, energy, environment fields, and beyond.