Publications
Inorganic-organic hybrid materials through post-synthesis modification: Impact of the treatment with azides on the mesopore structure
- Author(s)
- Miriam Keppeler, Jürgen Holzbock, Johanna Akbarzadeh, Herwig Peterlik, Nicola Hüsing
- Abstract
Hybrid, hierarchically organized, monolithic silica gels, comprising periodically arranged mesopores and a cellular macroscopic network, have been prepared through a co-condensation reaction of tetrakis(2-hydroxyethyl)orthosilicate with chloromethyl-trimethoxysilane or 3-(chloropropyl)-triethoxysilane. Subsequent conversion of the chloro groups into azido groups, by nucleophilic substitution with NaN3 in N,N-dimethylformamide, was conducted upon preservation of the monolithic structure. However, treatment with NaN3 had a strong influence on the structure in the mesoporous regime, with changes such as an increase of mesopore diameter, pore volume and lattice constants, as well as a concomitant decrease of the pore wall thickness, as confirmed by small angle X-ray scattering, transmission electron microscopy, and nitrogen sorption analysis. Similar effects were observed for unmodified silica gels by simple ageing in azide-containing media, whether a relatively small or a sterically demanding counter ion (Na+ or (H3C)4N+) was used. The structural modification did not seem to depend greatly on whether an organic aprotic solvent (N,N-dimethylformamide, 1,1,3,3-tetramethylurea, 1,3-dimethyl-2-imidazolidinone) or a protic solvent that can form hydrogen bonds, such as water, was used.
- Organisation(s)
- Dynamics of Condensed Systems
- External organisation(s)
- Universität Ulm, Paris-Lodron Universität Salzburg
- Journal
- Beilstein Journal of Nanotechnology
- Volume
- 2
- Pages
- 486-498
- No. of pages
- 12
- DOI
- https://doi.org/10.3762/bjnano.2.52
- Publication date
- 2011
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103015 Condensed matter, 103018 Materials physics
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/inorganicorganic-hybrid-materials-through-postsynthesis-modification-impact-of-the-treatment-with-azides-on-the-mesopore-structure(b47bdd6b-8c02-4aff-9767-3db6b9def624).html