Tunable porosity in bridged organosilicas using self-organizing precursors
Functionalized, mesoporous organosilicas with tunable porosity were prepared by a direct and simple approach from rationally designed precursors, combining the function of a network builder and a porogen in one molecule. The precursors are synthesized using a dual hydroboration reaction, fulfilling...
| Publié dans: | Langmuir : the ACS journal of surfaces and colloids. - 1985. - 24(2008), 21 vom: 04. Nov., Seite 12539-46 |
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| Auteur principal: | |
| Autres auteurs: | , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2008
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| Accès à la collection: | Langmuir : the ACS journal of surfaces and colloids |
| Sujets: | Journal Article |
| Résumé: | Functionalized, mesoporous organosilicas with tunable porosity were prepared by a direct and simple approach from rationally designed precursors, combining the function of a network builder and a porogen in one molecule. The precursors are synthesized using a dual hydroboration reaction, fulfilling the criteria of "click-chemistry", first on an ethylene-bridged organosilica and then on a long-chain alkene. Thus, in the final molecule the boron atom connects the sol-gel precursor (the bridged organosilica) with the porogen (the long-chain alkene). The so-prepared precursors do self-organize when hydrolysis of their inorganic moiety takes place via an aggregation of their organic side chains into hydrophobic domains. The length of the attached chain influences the size of the hydrophobic domain and thus, after a condensation-aminolysis sequence, the finally observed porosity of the organosilicas. Depending on chain length micro- to mesoporous materials with average pore sizes from 1.5 to 4.1 nm (for attached pentene to hexadecene chains) are observed. Furthermore, the boron entity enables the subsequent introduction of various functional groups into the pore walls of the organosilica networks. Amine or hydroxyl functionalities can be easily introduced, dependent on the experimental conditions used during the borane cleavage and extraction step. The accessibility of these functionalities can be proven by a significant metal adsorption onto the functional organosilica walls |
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| Description: | Date Completed 01.12.2008 Date Revised 30.10.2008 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la801374u |