Phase-Changeable Metafabric Enables Dynamic Subambient Humidity and Thermal Regulation.

Abstract

A promising approach to prevent heat- and cold-related illnesses is the integration of zero-energy input control technology into personal thermal management (PTM) systems while reducing energy consumption. However, achieving optimal wearing comfort while maintaining subambient metabolic temperatures using thermally regulating materials without an energy supply remains challenging. In this study, we provide a simple and reliable methodology to produce a phase-changeable metafabric made of thermoplastic polyurethane and phase change capsule (PCC) particles with high moisture permeability and thermal comfort. This approach skillfully incorporates spray-formed PCC particles into a three-dimensional nanofibrous aggregate, forming a stable self-entangled network structure in a single step through simultaneous humidity-assisted electrospraying and electrospinning processes. Additionally, the metafabric demonstrates prominent water resistance and superhydrophobicity, which are attributed to the integration of PCC particles and nanofibers, resulting in the formation of a microporous/nanoporous structure resembling the surface of a lotus leaf. As a result, the phase-changeable metafabric shows an active and passive thermal control performance, with a water vapor transmittance rate of 13.1 kg m-2 d-1 and a phase change enthalpy of 115.05 J g-1 even after 100 thermal cycles. Furthermore, it displays excellent waterproofing capability, characterized by a water contact angle of 158.7° and the ability to withstand a high hydrostatic pressure of 87 kPa. In addition, the metafabric exhibits a good mechanical performance, boasting a tensile strength of 10.5 MPa. Overall, the proposed economical metafabric is an exemplary candidate material for next-generation PTM systems.