Mechanically\nStable Thermally Crosslinked Poly(acrylic\nacid)/Reduced Graphene Oxide Aerogels

Abstract

Graphene oxide (GO) aerogels, high\nporosity (>99%) low density\n(∼3–10 mg cm^–3) porous materials with\nGO pore walls, are particularly attractive due to their lightweight,\nhigh surface area, and potential use in environmental remediation,\nsuperhydrophobic and superoleophilic materials, energy storage, etc.\nHowever, pure GO aerogels are generally weak and delicate which complicates\ntheir handling and potentially limits their commercial implementation.\nThe focus of this work was to synthesize highly elastic, mechanically\nstable aerogels that are robust and easy to handle without substantially\nsacrificing their high porosity or low density. To overcome this challenge,\na small amount of readily available and thermally cross-linkable poly­(acrylic\nacid) (PAA) was intermixed with GO to enhance the mechanical integrity\nof the aerogel without disrupting other desirable characteristic properties.\nThis method is a simple straightforward procedure that does not include\nmultistep or complicated chemical reactions, and it produces aerogels\nwith mass densities of about 4–6 mg cm^–3 and\n>99.6% porosity that can reversibly support up to 10 000\ntimes\ntheir weight with full recovery of their original volume. Finally,\npressure sensing capabilities were demonstrated and their oil absorption\ncapacities were measured to be around 120 g oil per g aerogel^–1 which highlights their potential use in practical\napplications.