Keywords and Phrases
Aerogels; Boric Acid; Mineral Acids; Ferrocene; Heterogeneous Catalysis; Isocyanates; Porous Polyamide; Polyurea; Polyimide
"Aerogels are low-density materials consisting of 3D assemblies of nanoparticles with high open porosities and surface areas. Inspired by the extraordinary mechanical strength of polymer crosslinked aerogels, our recent attention is focused on inexpensive multifunctional isocyanates reacting with a variety of aromatic, organometallic and inorganic monomers. Three such systems discussed here are:
(A) Polymeric aerogels synthesized via a room temperature reaction of an aromatic triisocyanate with pyromellitic acid. Using solid-state CPMAS 13C and 15N NMR, it was found that the skeletal framework was a statistical co-polymer of polyamide, polyurea and polyimide. Stepwise pyrolytic decomposition followed by reactive etching of those components yielded microporous carbon aerogels with good gas sorption selectivities that may find application in CO2 capture and sequestration.
(B) Ferrocene-polyamide aerogels prepared in one pot via reaction of an aromatic triisocyanate and ferrocene dicarboxylic acid. Upon pyrolysis (≥800 ⁰C / H2), monolithic Fe(0)-doped C-aerogels were obtained followed by quantitative transmetalation with noble metals (M: Au, Pt, Pd). The latter were demonstrated as heterogeneous catalysts in high yield reduction, oxidation and Heck coupling reactions. The monolithic catalysts were reused several times without loss of activity.
(C) Polyureas formed via reaction of an aromatic isocyanate with several mineral acids, (H3BO3, H3PO4, H3PO3, H2SeO3, H6TeO6, H5IO6 and H3AuO3). The residual boron in the H3BO3 model system was very low (≤0.05 % w/w), leaving pure polyurea as product and ruling out any process, in analogy to that with carboxylic acids, for systematic incorporation of H3BO3 in the polymeric chains"--Abstract, page v.
Al-Dahhan, Muthanna H.
Ph. D. in Chemistry
United States. Army Research Office
BASF Polyurethanes GmbH
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- Selective CO2 sequestration with monolithic bimodal micro/macroporous carbon aerogels derived from polyamide-polyimide-polyurea random co-polymers
- Reuseable monolithic nanoporous graphite-supported nanocatalysts (Fe, Au, Pt, Pd, Ni and Rh) from pyrolysis and galvanic transmetalation of ferrocene-based polyamide aerogels
- Nanoporous polyurea from a triisocyanate and boric acid: A paradigm of a general reaction pathway for isocyanates and mineral acids
xx, 261 pages
© 2016 Malik Adnan Saeed, All rights reserved.
Dissertation - Open Access
Aerogels -- Design
Electronic OCLC #
Saeed, Malik Adnan, "Functional nanoporous polyamide aerogels" (2016). Doctoral Dissertations. 2546.