3D-Printed Bentonite-Graphite Composite Materials Inspired by Pencil Lead

Traditional 3D-printed conductive composites face limitations in widespread application due to the weak heat resistance, poor corrosion resistance, and high cost of their matrix material. Inspired by pencil lead, 3D-printable bentonite-graphite (HB) composite inks have been developed. Ammonium sulfate (AS) solution is selected to increase graphite content and achieve uniform drying shrinkage. The 3D-printed greenware is sintered at a high temperature of 1000°C to obtain a composite clay with shape stability and functional diversity. Notably, the 3D-printed H8B2 clay with 60% infill density exhibits a compressive strength of 3.5 MPa, resistivity of 3.77 Ω·cm and a surface resistance of 108.63 Ω. Based on the formability and high conductivity of HB composites, multifunctional 3D-printed lightweight products with high specific surface areas and complex shape designs play a crucial role in fields such as thermal management, electromagnetic protection, electrolytic hydrogen, adsorption filtration, and energy batteries.