Versatile and Comfortable Janus Fabrics for Switchable Personal Thermal Management and Electromagnetic Interference Shielding

Existing personal thermal regulating fabrics fall short of meeting the demands for sustainable and protective outdoor temperature management. Here, a versatile and comfortable Janus fabric has been developed by embedding boron nitride nanosheets within a porous polyurethane matrix (BNNS@TPU) and introducing Ti 3 C 2 T x MXene into another layer of TPU pores (MXene/TPU). The well-distributed BNNS in porous TPU matrix enhances refractive index difference, increases porosity and optimizes pore size distribution, resulting in an excellent solar reflectivity ( R  = 94.22%), while the distinct distribution of MXene in porous TPU effectively improves solar absorptivity ( α  = 93.57%) and enhances the conduction loss of electromagnetic waves due to multiple scattering and reflection effects. With a simple flip, Janus fabric can switch between sub-ambient cooling of ~ 7.2 °C and super-ambient heating of ~ 46.0 °C to adapt to changing weather and seasonal conditions. The fabric achieves an electromagnetic interference shielding efficiency of 36 dB, protecting the human body from electromagnetic radiation, attributed to the hierarchical distribution of highly conductive MXene. Furthermore, Janus fabric offers excellent comfort, abrasion resistance, washability, and flame retardancy for practical wear. This study presents an effective strategy for developing personal thermal regulating fabrics with adaptability to environmental changes and resistance to electromagnetic radiation. Graphical abstract