Pore ordering in mesoporous matrices induced by different directing agents
| Autor: | Cătălin Ianăşi, Kinga Noémi Székely, Liviu Sacarescu, László Almásy, Cecilia Savii, Jiri Plocek, Ana-Maria Putz, Paula Sfârloagă, Zoltán Dudás |
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| Rok vydání: | 2017 |
| Předmět: |
inorganic chemicals
Condensed Matter - Materials Science Materials science Scanning electron microscope Mechanical Engineering Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Mesoporous silica Catalysis Tetraethyl orthosilicate chemistry.chemical_compound chemistry Chemical engineering Mechanics of Materials Bromide General Materials Science Mesoporous material Porosity Thermal analysis |
| DOI: | 10.48550/arxiv.1702.00366 |
| Popis: | Mesoporous silica particles of MCM-41 type were synthesized by sol-gel method from tetraethyl orthosilicate (TEOS) in 2-methoxyethanol and deionized water mixture in base conditions at room temperature. Ammonia or sodium hydroxides were used as catalysts and cetyl-trimethylammonium bromide (CTAB) and n-dodecyl-trimethylammonium bromide (DTAB) as structure directing agents. The porosities and the ordered structure have been analyzed using transmission and scanning electron microscopy, small angle neutron and X-ray diffraction, nitrogen adsorption, thermal analysis and FTIR spectroscopy. The samples consist of spherical particles of sub-micrometer size, with radially arranged pores. The comparison of the effect of the different surfactants and catalysts shows that by varying the surfactant type and their proportion, the pore sizes can be controlled. As compared to the commonly used ammonia catalyst, the use of NaOH as catalyst results in a much smaller porosity of the as-prepared materials. These materials are not resisting to the heat treatment at 700 C used for the template removal, and the ordered porous structure is completely lost. |
| Databáze: | OpenAIRE |
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