3D-printable Boron Nitride/Polyacrylic Hydrogel Composites with High Thermal Conductivities

Polyacrylic acid (PAA) hydrogel composites with different hexagonal boron nitride (h-BN) fillers were synthesized and successfully 3D-printed while their thermal conductivity was systematically studied. With the content of h-BN increasing from 0.1 wt% to 0.3 wt%, the thermal conductivity of the 3D-printed composites has been improved. Moreover, through the shear force given by the 3D printer, a complete thermal conductivity path is obtained inside the hydrogel, which significantly improves the thermal conductivity of the h-BN hydrogel composites. The maximum thermal conductivity is 0.880 8 W/(m·K), leading to a thermal conductive enhancement of 1 000%, compared with the thermal conductivity of pure PAA hydrogels. This study shows that using h-BN fillers can effectively and significantly improve the thermal conductivity of hydrogel-based materials while its 3D-printable ability has been maintained.