Robust nanoporous alumina monoliths by atomic layer deposition on low-density carbon-nanotube scaffolds

• Published in: Carbon (New York) 2014-07, Vol.73 (C), p.443-447
• Main Authors: Shin, S.J., Tran, I.C., Willey, T.M., van Buuren, T., Ilavsky, J., Biener, M.M., Worsley, M.A., Hamza, A.V., Kucheyev, S.O.
• Format: Article
• Language: English
• Subjects: Aerogels; Aluminum oxide; Carbon; Chemistry; Colloidal state and disperse state; Cross-disciplinary physics: materials science; rheology; Density; Deposition; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; General and physical chemistry; MATERIALS SCIENCE; Morphology; Nanoscale materials and structures: fabrication and characterization; NANOSCIENCE AND NANOTECHNOLOGY; Nanostructure; Nanotubes; Physics; Porous materials; Scaffolds; Specific materials
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2014.03.006

Synthesis of nanoporous alumina monoliths with controlled morphology and density is a challenge. Here, we demonstrate mechanically robust alumina monoliths synthesized by conformal overcoating of graphitic nanoligaments of low-density carbon-nanotube-based aerogels (CNT-CAs) by using atomic layer deposition. Young’s modulus of resultant monoliths increases superlinearly with the monolith density with an exponent of ∼2.4, defined by the morphology and connectivity of the CNT-CA scaffold. As a result, for a given monolith density, alumina-carbon composites have moduli comparable to those of CNT-CAs and significantly superior to those of pure alumina aerogels reported previously.