Graphene, a two-dimensional (2D) form of carbon, has generated extreme excitement since its discovery in 2004, due to its startling electrical, mechanical, and thermal properties. Yet, difficulties in realizing large-scale manufacturability of graphene has hindered mass adoption into target applications such as nanoelectronics, batteries, sensing and composites. Graphene aerogels, a class of materials made of 2D graphene sheets covalently crosslinked into a three-dimensional (3D) structure, largely retain many of the extraordinary properties of their graphene building blocks but are limited in size only by the container used during synthesis. In this work, graphene-based hydrogel synthesis in gravity (on Earth) and microgravity (on the International Space Station, ISS) conditions will be examined. Through experimentation in microgravity on the ISS, gravity-driven processes such as sedimentation and buoyancy-driven convection will be hindered, and underlying phenomena contributing to graphene aerogel assembly (e.g., random Brownian motion) will be isolated and investigated for the first time. This collaborative program also aims to reach elementary school students, undergraduate students, graduate students and the general public to raise awareness of the fields of nanotechnology and aerospace engineering, as well as careers in academia.
To extend the knowledge of space-produced aerogel, we will compare the properties of microgravity-synthesized graphene aerogels to Earth-synthesized aerogels. The objectives are two-fold: (1) to study the growth behavior (cross-linking, agglomeration, drying) of graphene aerogels (GA) synthesis outside the presence of gravity; and (2) to examine and explain the influence of microgravity-based synthesis on the 3-dimensional (3D) mesostructure and multi-physical properties (thermal transport, mechanical behavior, and electrical characteristics) of GAs. Ultimately, this work will provide the foundation for engineering of graphene aerogels (and other aerogels) with highly homogenous microstructures and correspondingly superior electrical, mechanical, and thermal properties to enable a wide variety of Earth and space applications, such as, ultra-lightweight structural materials, supercapacitor and battery electrodes, hydrogen storage, and water treatment membranes. In addition, in-space production of aerogels on the ISS may enable direct use of materials and devices by ISS researchers and for future space missions.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
