Flexible Wheat Bran Aerogel-Based Phase Change Composites for Wearable Thermotherapy Management

Abstract

Phase change materials (PCMs) offer great potential for wearable personal thermotherapy management (PTM) due to superior thermal energy storage and a consistent phase change temperature. Nevertheless, leakage during solid–liquid phase change and the intrinsic solid rigidity of PCMs are long-standing challenges in practical applications. Herein, we report a facile and cost-effective strategy to develop a multifunctional and flexible phase change composite (PCC) consisting of a modified wheat bran (MWB) aerogel and a styrene–isoprene–styrene block copolymer/poly(ethylene glycol) (SIS/PEG) blend. The MWB was first acquired by combining starch gelatinization, chemical cross-linking, conductive reinforcement of a nanofiller (MWCNT/OH), and freeze-drying. Then, the (final) flexible PCC was fabricated through MWB incorporating a phase change dispersion solution (SPEG) that was obtained by blending SIS with PEG. The resultant PCC exhibited excellent leakage-proof properties and good shape stability. The incorporation of SIS enabled MWB/SPEG to maintain superior mechanical flexibility and elastic recovery in both nonphase change and phase change states. The MWB/SPEG displayed high heat enthalpy of melting/crystallization values of 94.9 and 80.8 J/g, respectively. The integration of MWB/SPEG with conductive fabrics achieved residual heat storage/release and maintained the human body’s comfortable temperature in thermotherapy simulation. It provided promising potential in wearable thermal management for this flexible composite.