The Influence of pH on the Structure of Templated Mesoporous Silicas Prepared from Sodium Metasilicate

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Title:The Influence of pH on the Structure of Templated Mesoporous Silicas Prepared from Sodium Metasilicate
Creators:
Kooyman, Patricia J.
Slabová, Markéta
Bosáček, Vladimír
Čejka, Jiří
Rathouský, Jiří
Zukal, Arnošt
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 66, 4, pp. 555-566
Uncontrolled Keywords:Silicates, Molecular sieves, Mesoporous silicas, Powder X-ray diffraction, <sup>29</sup>Si MAS NMR spectroscopy, Homogeneous precipitation, MCM-41

Abstract

A recently developed homogeneous precipitation method was used for the investigation of the influence of pH on the structure of mesoporous silicas prepared from sodium metasilicate in the presence of a quaternary alkyl ammonium surfactant as a structure directing agent. The rate of pH decrease affects the assembly of mesoscopically ordered composites and, consequently, the porous structure of mesoporous silicas prepared from them by calcination. Pure MCM-41 molecular sieve was prepared by controlling the pH decrease of the reaction mixture so as to achieve the final pH 7.8. The as-made material prepared at higher pH (final value 10.1) is characterized by a lower degree of silica polycondensation. Due to the shrinkage of this material during calcination, a less well-ordered silica with extraordinary large surface area was prepared. A large decrease in pH (final value 5.2) led to non-organized polycondensation of silica species besides the organized assembly of the ordered material, which resulted in the formation of silica with a bimodal mesoporous structure. <p>

Title:The Influence of pH on the Structure of Templated Mesoporous Silicas Prepared from Sodium Metasilicate
Creators:
Kooyman, Patricia J.
Slabová, Markéta
Bosáček, Vladimír
Čejka, Jiří
Rathouský, Jiří
Zukal, Arnošt
Uncontrolled Keywords:Silicates, Molecular sieves, Mesoporous silicas, Powder X-ray diffraction, <sup>29</sup>Si MAS NMR spectroscopy, Homogeneous precipitation, MCM-41
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:66
Number:4
Page Range:pp. 555-566
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20010555UNSPECIFIED
ID Code:1810
Item Type:Article
Deposited On:06 Feb 2009 17:12
Last Modified:06 Feb 2009 16:12

Citation

Kooyman, Patricia J.; Slabová, Markéta; Bosáček, Vladimír; Čejka, Jiří; Rathouský, Jiří; Zukal, Arnošt (2001) The Influence of pH on the Structure of Templated Mesoporous Silicas Prepared from Sodium Metasilicate. Collection of Czechoslovak Chemical Communications, 66 (4). pp. 555-566. ISSN 0010-0765

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