Engineered ambient-pressure-dried TOCNF/CGG aerogel with dual crosslinking strategy and its performance in electromagnetic interference shielding

Amid the global drive towards green development, biomass aerogels have garnered significant attention in the domain of electromagnetic interference (EMI) shielding materials due to their abundant sources, high porosity, and large specific surface area. Nevertheless, the development of an easy-to-operate and eco-friendly method for large-scale production of biomass aerogels remains a formidable challenge. Herein, a dual crosslinking system assisted ambient pressure drying strategy is proposed to fabricate biomass EMI shielding aerogels without specialized conditions and equipment. Specifically, TEMPO-oxidized cellulose nanofiber (TOCNF) combines with cationic guar gum (CGG) and Fe 3+ to form a double crosslinked network through the electrostatic interaction and ionic bonding, yielding hydrogels that encapsulate carbon nanotube (CNT). The resulting hydrogels were sequentially subjected to freeze-thaw cycles, solvent replacement and ambient pressure drying to obtain TOCNF/CGG/Fe 3+ /CNT (TCFC) aerogel. The TCFC aerogel delivered good EMI shielding effectiveness (EMI SE) of 62.65 dB at a density of 0.1071 g cm −3 with the SSE (SE/density) of 584.98 dB cm 3 g −1 . Moreover, the incorporation of polydimethylsiloxane further protects the aerogels in complex environments to maintain their EMI shielding performance. This work provides a novel strategy for the construction of ambient-pressure-dried biomass aerogels, potentially inspiring new directions in the development of EMI shielding aerogels.