Molecular ordering of mixed surfactants in mesoporous silicas: A solid-state NMR study
| Autor: | Shy-Guey Wang, Marek Pruski, Victor S.-Y. Lin, Takeshi Kobayashi, Kanmi Mao |
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| Rok vydání: | 2011 |
| Předmět: |
Nuclear and High Energy Physics
Radiation Inorganic chemistry General Chemistry Nuclear magnetic resonance spectroscopy Mesoporous silica Crystallography chemistry.chemical_compound chemistry Heteronuclear molecule Solid-state nuclear magnetic resonance Bromide Magic angle spinning Mesoporous material Instrumentation Two-dimensional nuclear magnetic resonance spectroscopy |
| Zdroj: | Solid State Nuclear Magnetic Resonance. 39:65-71 |
| ISSN: | 0926-2040 |
| DOI: | 10.1016/j.ssnmr.2011.02.001 |
| Popis: | The use of mixed surfactants in the synthesis of mesoporous silica nanoparticles (MSNs) is of importance in the context of adjusting pore structures, sizes and morphologies. In the present study, the arrangement of molecules in micelles produced from a mixture of two surfactants, cetyltrimethylammonium bromide (CTAB) and cetylpyridinium bromide (CPB) was detailed by solid-state NMR spectroscopy. Proximities of methyl protons in the trimethylammonium headgroup of CTAB and protons in the pyridinium headgroup of CPB were observed under fast magic angle spinning (MAS) by {sup 1}H-{sup 1}H double quantum (DQ) MAS NMR and NOESY. This result suggested that CTAB and CPB co-exist in the pores without forming significant monocomponent domain structures. {sup 1}H-{sup 29}Si heteronuclear correlation (HETCOR) NMR showed that protons in the headgroups of CTAB are in closer proximity to the silica surface than those in the CPB headgroups. The structural information obtained in this investigation leads to better understanding of the mechanisms of self-assembly and their role in determining the structure and morphology of mesoporous materials. |
| Databáze: | OpenAIRE |
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