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Titolo:
Zeolite growth by addition of subcolloidal particles: Modeling and experimental validation
Autore:
Nikolakis, V; Kokkoli, E; Tirrell, M; Tsapatsis, M; Vlachos, DG;
Indirizzi:
Univ Massachusetts, Dept Chem Engn, Amherst, MA 01003 USA Univ Massachusetts Amherst MA USA 01003 Chem Engn, Amherst, MA 01003 USA Univ Calif Santa Barbara, Dept Chem Engn, Mat Res Lab, Santa Barbara, CA 93106 USA Univ Calif Santa Barbara Santa Barbara CA USA 93106 Barbara, CA 93106 USA Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA Univ CalifSanta Barbara Santa Barbara CA USA 93106 Barbara, CA 93106 USA
Titolo Testata:
CHEMISTRY OF MATERIALS
fascicolo: 3, volume: 12, anno: 2000,
pagine: 845 - 853
SICI:
0897-4756(200003)12:3<845:ZGBAOS>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
SI-TPA-MFI; INITIAL-STAGE; SMALL-ANGLE; CRYSTALLIZATION; TPA-SILICALITE-1; SILICALITE; SCATTERING; NUCLEATION; MECHANISM; PRECURSORS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Engineering, Computing & Technology
Citazioni:
33
Recensione:
Indirizzi per estratti:
Indirizzo: Tsapatsis, M Univ Massachusetts, Dept Chem Engn, Amherst, MA 01003 USA Univ Massachusetts Amherst MA USA 01003 mherst, MA 01003 USA
Citazione:
V. Nikolakis et al., "Zeolite growth by addition of subcolloidal particles: Modeling and experimental validation", CHEM MATER, 12(3), 2000, pp. 845-853

Abstract

Seeded growth of tetrapropylammonium (TPA)-silicalite-1 is studied using simulations and dynamic light scattering, atomic force microscopy, and transmission electron microscopy experiments. The effects of the total silica concentration, temperature, and total seed concentration are examined. When the composition of silica in solution is above a critical value, growth is observed. In such a case, ;he size of the seeds increases linearly with time, with a growth rate that is not significantly affected by the total silicaconcentration. Growth appears to be activated with an activation energy ofsimilar to 90 kJ/mol for a range of seed concentrations. Transmission electron microscopy and dynamic light scattering indicate the presence of subcolloidal particles. Simulations of the growth of a static particle in a suspension of subcolloidal particles are carried out. Good agreement with experimental results regarding the growth rate and the apparent activation energy is possible by considering Derjaguin-Landau-Verwey-Overbeek (DLVO) interactions with electrostatic repulsion described with a constant surface charge model. The type of interaction was also verified with atomic force microscopy force measurements between a silicalite surface and a glass sphere. Byuse of these types of interactions, it is also possible tea explain the stability of the seeded suspension and show that only a relatively narrow size distribution of growth precursors participate in the growth of the seeds. Our results support the possibility that under the conditions studied, growth of silicalite seeds proceeds by a mechanism with the rate-limiting stepbeing the addition of subcolloidal particles.

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Documento generato il 05/12/20 alle ore 23:51:39