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Titolo:
Aging effects on the nucleation and crystallization kinetics of colloidal TPA-silicalite-l
Autore:
Li, QH; Mihailova, B; Creaser, D; Sterte, J;
Indirizzi:
Lulea Univ Technol, Dept Chem Technol, S-97187 Lulea, Sweden Lulea Univ Technol Lulea Sweden S-97187 m Technol, S-97187 Lulea, Sweden Bulgarian Acad Sci, Cent Lab Mineral & Crysallog, Sofia, Bulgaria Bulgarian Acad Sci Sofia Bulgaria Mineral & Crysallog, Sofia, Bulgaria
Titolo Testata:
MICROPOROUS AND MESOPOROUS MATERIALS
fascicolo: 1, volume: 43, anno: 2001,
pagine: 51 - 59
SICI:
1387-1811(200103)43:1<51:AEOTNA>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
VITREOUS SILICA; TEMPERATURE SYNTHESIS; LIGHT-SCATTERING; MFI ZEOLITE; TPA-SILICALITE-1; ZSM-5; IDENTIFICATION; SPECTROSCOPY; SYSTEM; PERIOD;
Keywords:
aging; TPA-silicalite-l; nucleation kinetics; varying-temperature synthesis; colloidal zeolite;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
30
Recensione:
Indirizzi per estratti:
Indirizzo: Li, QH Lulea Univ Technol, Dept Chem Technol, S-97187 Lulea, Sweden Lulea Univ Technol Lulea Sweden S-97187 ol, S-97187 Lulea, Sweden
Citazione:
Q.H. Li et al., "Aging effects on the nucleation and crystallization kinetics of colloidal TPA-silicalite-l", MICROP M M, 43(1), 2001, pp. 51-59

Abstract

A direct experimental method, involving a two-stage varying-temperature synthesis, was utilized to investigate the effects of aging on the nucleationkinetics for the synthesis of nanosized TPA-silicalite-1 with various silica sources, including tetraethoxysilane (TEOS) and amorphous silica Ludox TM. For TEOS aging had only a mild influence on the nucleation and crystallization kinetics, whereas for Ludox TM dramatic changes occurred. After extended aging periods, the nucleation kinetics for syntheses with Ludox TM became similar to those for syntheses with TEOS, leading to increasing similarities in the properties of the products of the crystallization. Independentof aging time and silica source, the nucleation processes occurred over a substantial period of time, extending over the induction period, but were completed before crystal growth was detected. With increased aging, the nucleation period was gradually decreased and tended to be completed earlier inthe induction period. Raman spectra revealed that with Ludox TM, aging enhanced the interaction between TPA(+) and the silica species, leading to an increase in the concentration of precursor species for nucleation, which inturn accelerated the nucleation rate. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 22/09/20 alle ore 22:32:15