Three-dimensional (3D) ultrathin foams of two-dimensional (2D) materials hold high potential for a variety of applications, including structure reinforcement, thermal management, and energy storage. However, their industrial adoption has been limited due to the substantial difficulties in controlling the pore size and strut wall thickness of the foams to desired dimensions with existing materials processing technologies. This award supports research to address this challenge, by investigating an original and novel process that can lead to highly controllable growth of 3D foams with tunable pore sizes. This research will accelerate the processing technology of 3D porous materials with substantial impact on an array of applications including energy storage, thermal management, and flexible electronics. It will also provide opportunities for educating the next generation workforce to enhance the competitiveness of the US in materials processing and manufacturing technologies.
The goal of this research is to investigate an innovative process for manufacturing 3D foam architectures of 2D ultrathin graphite (UG) as well as similar foams of dielectric 2D hexagonal boron nitride (h-BN) with controllable pore sizes between 1 micon and 100 microns, and tunable strut wall thickness from 1 to 1000 nm. The materials processing method consists of a new approach for fabricating Ni foams as catalytic templates with reduced pore sizes or multiple level porosity, an energy effective and rapid RF induction heating method for growth of large-scale UG and h-BN materials, and an efficient Ni etching process. This work will also establish a fundamental understanding of the effects of pore size, wall thickness, grain boundaries and structure on the thermal properties of UG and h-BN foams and composites. New knowledge in materials processing will be obtained for manufacturing 3D multilevel porous UG and h-BN materials with enhanced thermal management properties. The understanding and knowledge resulting from this work will also potentially lead to a general approach for manufacturing a variety of other 2D materials into 3D foam structures.