Biopolymer-inspired sodium alginate-bridged MWCNT/basalt fiber fabric for integrated EMI shielding, sound absorption, and joule-heating capabilities.

With the widespread application of electronic devices in complex environments-facing multiple challenges such as chemical corrosion, noise and electromagnetic radiation pollution-developing new electromagnetic interference (EMI) shielding materials combining high performance with durability become an urgent requirement. To address this, this study utilized natural basalt fibers (BF) and sodium alginate (SA) as substrates to construct a nano-Fe₃O₄@CNT conductive-magnetic network, taking advantage of the cross-linking reaction between SA and Ca2+ via coordination interactions, which enabled the coating to adhere onto the surface of BF fabrics. This fabric exhibited outstanding comprehensive properties, achieving an excellent EMI shielding of 39.44 dB, an EMI shielding effectiveness per unit thickness of 788.8 dB·cm-1, a sound absorption coefficient of 0.87, a mechanical strength of 229 MPa and stable joule heating capacity (approximately 70 °C). More importantly, after immersion in seawater, HCl, and NaOH, its SE retention rates reached 88%, 72%, and 87%, respectively, and the average sound absorption coefficient remained nearly unchanged. The multifunctional fabrics, "derived from nature and designed for nature", will provide a material that combines electromagnetic and acoustic protection for wearable clothing as well as short-term protected environments such as ship compartments and offshore platforms.