Triple-network synergistically enhanced polyurethane-based composite phase change materials for multi-source driven wearable thermal management

To address the growing demand for efficient energy conversion and storage materials in wearable personal thermal management (PTM), this study proposes a cooperative strategy of “molecular interface engineering + multi-scale structural design” to develop a flexible composite phase change material (PU-rG/Cu/C-PW) with a triple-network enhanced architecture. Using polyurethane foam (PU) as a scaffold, a uniform coating of reduced graphene oxide (rGO), copper nanowires (CuNWs), and carbon nanotubes (CNTs) was constructed via a cyclic impregnation-gradient reduction process, forming a “hard core-soft shell” porous micro/nano thermal conduction network. Paraffin wax (PW) was then stably encapsulated into the framework through vacuum melt infiltration. The resulting composite exhibits outstanding comprehensive properties: the mechanical strength of 128.44 kPa, the energy storage density of 159.81 J·g −1 , and the thermal conductivity of 0.702 W·m −1 K −1 , which is 331% higher than that of PW. The material maintains high flexibility and thermal reliability over 100 melting-solidification cycles. Moreover, under the conditions of 1.5 kW·m −2 simulated solar radiation and 10 V voltage, it demonstrated outstanding photothermal and electrothermal conversion efficiencies, reaching as high as 87.8% and 80.4% respectively. and has excellent multi-source drive thermal energy conversion capabilities. This work provides a novel material solution to overcome the long-standing challenges of leakage, low thermal conductivity, and poor mechanical strength in phase change materials (PCM), demonstrating great potential for applications in wearable electronics, solar energy utilization, and multi-source driven thermal management.