Janus liquid metal@MXene/Fe3O4 nanofiber membranes with polydopamine -confined liquid metal for electromagnetic interference shielding and infrared control

Electromagnetic interference (EMI) increasingly constrains the development of flexible and multifunctional electronics materials, yet asymmetric structural design and functional integration remain limited. Here we report a Janus hierarchical membrane, liquid metal@polydopamine-MXene/Fe 3 O 4 @cellulose polyacrylonitrile nanofibers (LM@PDA-MXene/Fe 3 O 4 @CPNF), fabricated by electrospinning a Fe 3 O 4 -doped cellulose/Polyacrylonitrile nanofiber scaffold and vacuum-assisted assembly of MXene intercalated with core-shell LM@PDA nanoparticles. The multiscale architecture couples three loss pathways: a percolated MXene network for conductive loss, LM@PDA spacers that suppress restacking and form microcapacitors for interfacial and dipolar polarization, and a porous magnetic entrance that improves impedance matching. In the X-band, a single 70 μm layer achieved an average EMI shielding effectiveness (SET) of 45.1 dB and a thickness-normalised specific shielding effectiveness (SSE/t) = 8.87 × 10 3 dB cm 2 g -1 , stacking four layers raised SET to 70.8 dB. The membrane also provided orientation-dependent thermal functions, this ultrathin, eco-friendly, and lightweight membrane integrates absorption-dominant EMI shielding with bidirectional thermal management in a single platform, offering a practical route toward electromagnetic protection and infrared control in next-generation wearable electronics.