A dual cooling composite film by subtly combining phase change materials and thermally conductive fillers for efficient thermal management

It is a long-term bottleneck to reasonably balance heat conduction and heat absorption for cost-effective thermal management applications. In the current study, a dual cooling polylactic acid (PLA) composite film was fabricated by subtly coating phase change materials of polyethylene glycol (PEG) onto the surface of thermally conductive fillers of hexagonal boron nitride (h-BN) (PEG@BN), where the thermal conductivity was greatly improved by decreasing the interfacial thermal resistance and the thermal transition of PEG was accelerated without any leakage. The thermal conductivity of (PEG@BN)/PLA at a low h-BN loading of 15.0 wt% was as high as 3.94 W m −1 K −1 , which was enhanced by 87.6% and 1131.3% relative to uncoated PEG/BN/PLA and pure PLA, respectively. Meanwhile, the latent heat of (PEG@BN)/PLA at a PEG content of 20.0 wt% was 12.1 J g −1 , exhibiting stable thermal performance. These results provide a paradigmatic strategy to develop dual cooling materials for efficient thermal management. Graphical abstract