Publikationen

Nucleophilic substitution on silica surfaces

Autor(en)
Miriam Keppeler, Juergen Holzbock, Johanna Akbarzadeh, Herwig Peterlik, Nicola Huesing
Abstrakt

Azido-group functionalized, hierarchically organized meso-/macroporous silica gels have been prepared through co-condensation of tetrakis(2-hydroxyethyl)orthosilicate with chloromethyltrimethoxysilane or 3-(chloropropyl)-triethoxysilane and subsequent conversion of the chloro groups. Azido functionalities have been obtained by nucleophilic substitution of the surface-bound chloro moieties with NaN3 in N,N-dimethylformamide. A strong dependence of the later azide density (N-3 groups nm(-2)) in the final material on the reaction conditions, such as temperature and time, but also on the spacer length (methylene versus propyl) of the organofunctional silane has been observed. In principle, the nucleophilic substitution benefits from higher reaction temperatures and times. However, while gamma-azido groups seem to be stable over a wide range of reaction temperatures and longer reaction times, alpha-azido moieties tend to decompose at temperatures above 60 degrees C. The structural features of the monolithic gels and the azide functionalities on the surface were determined by IR-ATR-spectroscopy, elemental analyses, N-2-sorption analyses, small angle X-ray scattering and transmission electron microscopy.

Organisation(en)
Dynamik Kondensierter Systeme, Fakultätszentrum für Nanostrukturforschung
Externe Organisation(en)
Universität Ulm, Paris-Lodron Universität Salzburg
Journal
Journal of the Ceramic Society of Japan
Band
123
Seiten
764-769
Anzahl der Seiten
6
ISSN
1882-0743
DOI
https://doi.org/10.2109/jcersj2.123.764
Publikationsdatum
09-2015
Peer-reviewed
Ja
ÖFOS 2012
Materialphysik
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/nucleophilic-substitution-on-silica-surfaces(32ed063b-6361-42a4-a038-1fc279906c28).html