Biomimetic Ambient‐Pressure‐Dried Aerogels with Oriented Microstructures for Enhanced Electromagnetic Shielding

• Published in: Advanced functional materials Vol. 35; no. 5
• Main Authors: Zhang, Yu‐Chuan, Ding, Rong, Su, Peng‐Gang, Zeng, Fu‐Rong, Jia, Xu‐Xu, Hu, Zai‐Yin, Wang, Yu‐Zhong, Zhao, Hai‐Bo
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.01.2025
• Subjects: aerogel; Aerogels; Alginates; ambient pressure drying; Biomimetic materials; Compressive strength; Drying; Electromagnetic interference; Electromagnetic shielding; Functional materials; Microstructure; oriented microstructures; Polyanilines; Prepolymers; Pressure; Surface tension; Ultrawideband
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202414683

Oriented aerogels, emerging as a new generation of lightweight electromagnetic interference (EMI) materials, often face complex synthesis processes. While creating an orderly oriented microstructure for EMI aerogels through ambient pressure drying (APD) shows promise, it remains a significant challenge. Here, inspired by the directional grown structure of the plant, a new strategy that employs rapid precursor orientation followed by slow cross‐linking to achieve the APD of directional EMI aerogels is proposed. This approach demonstrates that low‐temperature oriented polymerization of polyaniline enables strong cross‐linking with poly(3,4‐ethylenedioxythiophene) and alginate, forming a robust conductive directional skeleton and mitigating surface tension issues during mild drying. The resulting aerogel features high conductivity (48.84 S m−1), excellent flame retardancy, and impressive compressive strength. Notably, its sturdy frame allows for further enhancement with other functional materials, such as Mxene, through re‐processing and re‐drying. The tree‐branch‐like aerogel achieves a significantly improved EMI shielding effectiveness of 50.3 dB across an ultrawideband range of 8.2–40 GHz. This strategy offers a new idea for the straightforward preparation of functional aerogels with programmability and oriented microstructures using ambient drying. Inspired by the directional growth of plants, an ambient‐pressure‐dried strategy to synthesize electromagnetic interference aerogels with oriented microstructures is demonstrated. Low‐temperature polymerization of polyaniline enables cross‐linking with poly(3,4‐ethylenedioxythiophene) and alginate, forming a robust conductive directional skeleton and mitigating surface tension during drying. The aerogel is redryable and reprocessable, achieving an impressive shielding effectiveness across an ultrawideband range.