Self-assembly of colloidal zeolite precursors into extended hierarchically ordered solids
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
A new porous material containing both micropores and mesopores has been synthesized by the self-assembly of silicalite-1 colloidal precursors at low temperatures and thoroughly investigated by diffraction, electron microscopy, porosimetry, and spectroscopy. Our "bottom-up" approach yields mesoporous materials that contain a microporosity different from that of SBA-15. For the samples where the silicalite-1 mixture is aged at room temperature, we do not have conclusive evidence that silicalite-1 is responsible for the microporosity in our samples, as all analytical techniques are inconclusive. By contrast, samples where the silicalite-1 mixture is heated until Bragg reflections are observed appear by TEM to be heterogeneous materials containing both mesopores and domains of silicalite-1. Nitrogen and argon adsorption show that both the micropore size distribution and the total micropore volume of our samples are different from those of SBA-15. The conclusions from this study are fourfold: (1) we have created a material containing both micropores and mesopores that is very well ordered on the mesoscale, (2) our material has a larger micropore volume and different micropore size distribution than SBA-15 made under the same conditions, (3) we have achieved this high degree of structural ordering and uniformity without the need for high-temperature syntheses, and (4) it does not appear possible to use larger (≃50 nm) nanoparticles of silicalite-1 to fabricate homogeneous materials. The ability to synthesize these materials at low temperatures makes them (and the synthetic concept) ideal for extension into areas such as thin-film syntheses.
Details
Original language | English |
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Pages (from-to) | 3139-3146 |
Number of pages | 8 |
Journal | Chemistry of materials |
Volume | 16 |
Issue number | 16 |
Publication status | Published - 10 Aug 2004 |
Peer-reviewed | Yes |
Externally published | Yes |