Pseudomorphe Transformation mesostrukturierter Silikagele zu anderen Metalloxiden
Dissertation
Faculties
Fakultät für NaturwissenschaftenAbstract
Porous materials with high surface areas, well-defined pore sizes and long-range ordering of the packing of pores are of great importance in many applications. Sol-gel processing is a great tool towards the synthesis of highly porous featuring the above mentioned properties.
The aim of this work is the formation of macroporous magnesium oxide or titanium dioxide through one-step or multi-step gas-solid displacement reactions, using hierarchically organized silica monoliths as hard template.
In the first step, monolithic SiO2-preforms were prepared through sol-gel processing by using tetrakis(2-hydroxyethoxy)silane (EGMS) as precursor and the commercially available triblock copolymer Pluronic P123 (ethylene oxide)EO20(propylene oxide)PO70(ethylene oxide)EO20 as the structure-directing agent. The obtained SiO2-gels were dried by surface silylation treatment with trimethylchlorosilane and calcined at 650 °C.
For the transformation reactions magnesium powder or titanium(IV)fluoride were used as reagent. The influence of different reaction temperatures and conversion times were tested. The resulting chemical composition was analyzed by X-ray diffraction. The gel morphology and porosity were characterized by scanning and transmission electron microscopy and nitrogen physisorption.
Date created
2008
Subject headings
[GND]: Magnesiumoxid | Silicate | Siliciumdioxid | Titandioxid[LCSH]: Silicon dioxide
[Free subject headings]: Mesostrukturierte Silikagele | Pseudomorphe Transformation
[DDC subject group]: DDC 540 / Chemistry & allied sciences
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Please use this identifier to cite or link to this item: http://dx.doi.org/10.18725/OPARU-1121
Geist, Steffi (2008): Pseudomorphe Transformation mesostrukturierter Silikagele zu anderen Metalloxiden. Open Access Repositorium der Universität Ulm und Technischen Hochschule Ulm. Dissertation. http://dx.doi.org/10.18725/OPARU-1121
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