Polymer-derived ceramic/graphene oxide architected composite with high electrical conductivity and enhanced thermal resistance

摘要

A low temperature method for the fabrication of architected ceramic composites contining graphene is developed based on the infiltration of lightweight graphene oxide (GO) micro-lattices with a preceramic polymer. Self-supported highly porous three-dimensional (3D) GO structures fabricated by direct ink writing are infiltrated with a liquid organic-polysilazane (a compound of Si, C, H, N), and subsequently pyrolyzed at temperatures of 800-1000 degrees C to activate the ceramic conversion. These ceramic composites replicate the patterned GO skeleton and, whereas the graphene network provides the conductive path for the composite (electrical conductivity in the range 0.2-4 S cm(-1)), the ceramic wrapping serves as a protective barrier against atmosphere, temperature (up to 900 degrees C in air) and even direct flame. These structured composites also show hydrophobicity (wetting angle above 120 degrees) and better load bearing capacity than the corresponding 3D GO lattice. The process is very versatile, being applicable to different liquid precursors.