Additive Manufacturing Porous Carbon with Complex Geometries

Porous Carbon is important for applications such as filters, energy storage, and catalysts. Current manufacturing methods for producing these porous carbon structures are time and energy intensive, and use harmful chemicals. The popular Template method of porous carbon production is limited by the difficulty, inefficiency, and wastefulness of the template removal process. Alternatively, 3D printing aqueous inks loaded with polymeric carbon precursors offers a material-, cost-, and time-efficient route to mass producing carbon-based prints with complex geometries which yield carbon with tunable porosity upon heat treatment. Polyvinyl alcohol (PVA) is added for steric stabilization of the carbon precursors, in which the particles are coated with hydrophilic tails that prevent flocculation through weakening of the Van der Waals attractive forces between particles. This addition of PVA increases solids loading, which aids in mass manufacturing because it which reduces shrinkage upon drying, allowing for easy standardization amongst shape. A water solvation post-processing step removes the PVA to leave behind a geometry of carbon precursors. Upon this step we characterize the pore structure via micro-CT and SEM, and analyze the geometry with high precision 3D scanning, giving optimization parameters for finding the ideal PVA weight percent. In the future carbon doped with specific derivatives such as carbon black or CNTs can be added easily, allowing for other properties such as electrical conductivity to be altered.