Formation of Single-Walled Aluminosilicate Nanotubes from Molecular Precursors and Curved Nanoscale Intermediates.
We report the identification and elucidation of the mechanistic role of molecular precursors and nanoscale (1-3 nm) intermediates with intrinsic curvature in the formation of single-walled aluminosilicate nanotubes. We characterize the structural and compositional evolution of molecular and nanoscal...
| Publicado en: | Journal of the American Chemical Society Vol. 133; no. 14; pp. 5397 - 5413 |
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| Autores principales: | , , , , , |
| Formato: | Artículo |
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American Chemical Society
4/13/2011
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=60459653&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 60459653 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 4/13/2011 vid: 133 iid: 14 pid: 997 pub: American Chemical Society artinfo: ui: 60459653 10.1021/ja111055q ppf: 5397 ppct: 16 formats: tig: atl: Formation of Single-Walled Aluminosilicate Nanotubes from Molecular Precursors and Curved Nanoscale Intermediates. aug: au: Yucelen, G. Ipek Choudhury, Rudra Prosad Vyalikh, Anastasia Scheler, Ulrich Beckham, Haskell W. Nair, Sankar affil: School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States Leibniz-Institut flit Polymerforschung Dresden e.V., D-01069 Dresden, Germany School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States su: Nanotubes Aluminum silicates Electrospray ionization mass spectrometry Intermediates (Chemistry) Nuclear magnetic resonance spectroscopy sug: subj: Nanotubes Aluminum silicates Electrospray ionization mass spectrometry Intermediates (Chemistry) Nuclear magnetic resonance spectroscopy ab: We report the identification and elucidation of the mechanistic role of molecular precursors and nanoscale (1-3 nm) intermediates with intrinsic curvature in the formation of single-walled aluminosilicate nanotubes. We characterize the structural and compositional evolution of molecular and nanoscale species over a length scale of 0.1-100 nm by electrospray ionization mass spectrometry, nuclear magnetic resonance spectroscopy (Al liquid-state, Al and Si solid-state MAS), and dynamic light scattering. Together with structural optimization of key experimentally identified species by solvated density ftmnctional theory calculations, this study reveals the existence of intermediates with bonding environments, as well as intrinsic curvature, similar to the structure of the final nanotube product. We show that "proto-nanotube-like" intermediates with inherent curvature form in aqueous synthesis solutions immediately after initial hydrolysis of reactants, disappear from the solution upon heating to 95 °C due to condensation accompanied by an abrupt pH decrease, and finally form ordered single-walled aluminosiicate nanotubes. Detailed quantitative analysis of NMR and ESI-MS spectra from the relevant aluminosilicate, aluminate, and silicate solutions reveals the presence of a variety of monomeric and polymeric aluminate and aluminosiicate species (AlSiχ-AlSiχ), such as Keggin ions [AlOAl(OH)(HO)] and polynuclear species with a six-membered Al oxide ring unit. Our study also directly reveals the complexation of aluminate and aluminosiicate species with perchiorate species that most likely inhibit the formation of larger condensates or nontubular structures. Integration of all of our results leads to the construction of the first molecular-level mechanism of single-walled metal oxide nanotube formation, incorporating the role of monomeric and polymeric aluminosilicate species as well as larger nanoparticles. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2011 holdings: @attributes: islocal: N |
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