Freeze-Casting Produces a Graphene Oxide Aerogel with a Radial and Centrosymmetric Structure
Citations Over TimeTop 1% of 2018 papers
Abstract
We report the assembly of graphene oxide (G-O) building blocks into a vertical and radially aligned structure by a bidirectional freeze-casting approach. The crystallization of water to ice assembles the G-O sheets into a structure, a G-O aerogel whose local structure mimics turbine blades. The centimeter-scale radiating structure in this aerogel has many channels whose width increases with distance from the center. This was achieved by controlling the formation of the ice crystals in the aqueous G-O dispersion that grew radially in the shape of lamellae during freezing. Because the shape and size of ice crystals is influenced by the G-O sheets, different additives (ethanol, cellulose nanofibers, and chitosan) that can form hydrogen bonds with H2O were tested and found to affect the interaction between the G-O and formation of ice crystals, producing ice crystals with different shapes. A G-O/chitosan aerogel with a spiral pattern was also obtained. After chemical reduction of G-O, our aerogel exhibited elasticity and absorption capacity superior to that of graphene aerogels with "traditional" pore structures made by conventional freeze-casting. This methodology can be expanded to many other configurations and should widen the use of G-O (and reduced G-O and "graphenic") aerogels.
Related Papers
- → Current status, opportunities, and challenges in fuel cell catalytic application of aerogels(2019)44 cited
- → Synthesis of aerogel foams through a pressurized sol-gel method(2020)18 cited
- → Utilization of aerogel in building construction –A Review(2020)19 cited
- → Dynamic behaviors of fiber reinforced aerogel and Mg/aerogel composites(2011)
- Aerogel + Aerogel = Aerogel²Developments on Aerogel-Aerogel Composites(2011)