Weavable phase change fibers with wide thermal management temperature range, reversible thermochromic and triple shape memory functions towards human thermal management

Developing multifunctional phase change materials that could be employed in human thermal management is of great significance for enhancing personal comfort. However, limited thermal management temperature range, strong rigidity and lack of effective visual thermal management approach still hinder their extensive application. In this work, flexible phase change fibers (PCFs) were fabricated by encapsulating the phase change mixtures blended with paraffin wax (PW, Tm = 62.0 °C), nonadecane (NO, Tm = 31.9 °C), and thermochromic agent (TA) into polydimethylsiloxane (PDMS) hollow tubes via a vacuum injection method. PW/NO/PDMS PCFs possessed dual phase change temperature regions around 31.9 °C and 62.0 °C, which broadened the thermal management temperature range. TA realized the visualization of the phase transition of NO and PW via the red-yellow-green color evolution. Combined the dual phase transitions of PW/NO with the elastic PDMS tube, the PCFs exhibited excellent triple shape memory effects. Fabrics woven with PCFs can provide intelligent thermal management functions to keep the temperature constant and improve comfort of humans in hot/cold situations. Therefore, this study provides a facile strategy for fabricating weavable PCFs with wide thermal management temperature range, thermochromic and triple shape memory properties, which have great potential in intelligent thermal management for humans.