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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 18, Number 4
BKCSDE 18(4)
April 20, 1997 

 
Title
Optimization of Synthetic Parameters for Mesoporous Molecular Sieve MCM-41 Using Surfactant CTACl
Author
Dong Ho Park, Chi-Feng Cheng, Jacek Klinowski
Keywords
Abstract
High quality MCM-41 is prepared from a gel of molar composition SiO2:0.20 CTACl:0.18 TMAOH:25 H2O aged at 20 ℃ for 24 hours before crystallization lasting for 48 hours. The (110) and (200) peaks of XRD pattern of high quality MCM-41 are unusually well resolved and the FWHM (full-width-at-half-maximum) of the (100) peak is 0.13° for as-prepared MCM-41 and 0.21° for calcined one, which indicate well-developed crystals. The properties of the crystal depend on the source and concentration of the reactants and the gel aging time. There is no induction period in the course of the synthesis, which is conveniently monitored by pH measurement. Gel aging, during which a spatial distribution of silicate polyanions and micellar cations is established, is essential for preparing high quality MCM-41. Surfactants with the same cationic organic group but different counteranions change the crystallization behavior. Highly basic gel (pH=12.6) favours the lamellar product; the quality of MCM-41 is lower as insufficient TMAOH is available to dissolve the silica.
Page
379 - 384
Full Text
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