Dual-functional phase change hydrogels with boron nitride networks: High-Performance thermal interface materials for electronics cooling

With the rapid development of high-frequency 5G communication technologies, thermal management demands for electronics have surged, posing critical challenges for thermal interface materials (TIMs), including insufficient thermal conductivity, excessive interfacial thermal resistance, and phase-change material leakage. To address these, this study designed a boron nitride (BN)-reinforced composite phase-change hydrogel: Polyvinyl alcohol (PVA)/sodium alginate (SA)/BN/OP44. Thermal conduction pathways were built based on a 3D PVA/SA network via gradient BN filling, and OP44 was encapsulated within a PVA/SA cross-linked network, addressing the trade-off between heat transfer, storage, and stability. Results show the optimized composite with 14 BN mass fraction (wt%) BN (PS–O–B₄) achieves a thermal conductivity of 1.16 W/(m·K) (346 % enhancement over pure OP44), low thermal resistance of 27.63 (°C cm²)/W, and mass retention >96.5 % after 8 thermal cycles. DSC confirms a melting range (39.1–40 °C) matching chip conditions, with latent heat retention >97.5 %. Thermal simulation shows the material delays temperature rise via phase-change and enables steady dissipation via the BN network. This work provides a novel paradigm for designing TIMs with high conduction, low resistance, and stability, advancing practical dynamic thermal management. The material demonstrates commercialization potential for high-power 5G devices.