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Assessment of Porosities of SBA-15 and MCM-41 Using Water Sorption Calorimetry.

Kocherbitov, Vitaly LU and Alfredsson, Viveka LU (2011) In Langmuir 27(7). p.3889-3897
Abstract
Water sorption calorimetry has been used for characterization of 2D hexagonally ordered mesoporous silica SBA-15. Experimental data on water sorption isotherm, the enthalpy, and the entropy of hydration of SBA-15 are presented. The results were compared with previously published results on MCM-41 obtained using the same technique. The water sorption isotherm of SBA-15 consists of four regimes, while the sorption isotherm of MCM-41 consists only of three. The extra regime in the water sorption isotherm for SBA-15 arises from filling of intrawall pores, that are present in SBA-15 but absent in MCM-41. The water sorption isotherms of the two types of mesoporous silica were analyzed using the Barrett-Joyner-Halenda approach. For the BJH... (More)
Water sorption calorimetry has been used for characterization of 2D hexagonally ordered mesoporous silica SBA-15. Experimental data on water sorption isotherm, the enthalpy, and the entropy of hydration of SBA-15 are presented. The results were compared with previously published results on MCM-41 obtained using the same technique. The water sorption isotherm of SBA-15 consists of four regimes, while the sorption isotherm of MCM-41 consists only of three. The extra regime in the water sorption isotherm for SBA-15 arises from filling of intrawall pores, that are present in SBA-15 but absent in MCM-41. The water sorption isotherms of the two types of mesoporous silica were analyzed using the Barrett-Joyner-Halenda approach. For the BJH analysis, t-curves of silica with different degrees of hydroxylation were proposed. Comparison of water and nitrogen t-curves shows that, independent of hydroxylation of silica surface, the adsorbed film of water is much thinner than the adsorbed film of nitrogen at similar relative pressures. This fact decreases the uncertainty of the assessment of porosity with water sorption originated from variations in surface properties. The pore size distribution of SBA-15 calculated with BJH treatment of water sorption data is in good agreement with nitrogen NLDFT results on the same material. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
27
issue
7
pages
3889 - 3897
publisher
The American Chemical Society
external identifiers
  • wos:000288970900087
  • pmid:21366316
  • scopus:79953244223
ISSN
0743-7463
DOI
10.1021/la103807v
language
English
LU publication?
yes
id
71b5e8c0-1fee-441b-8c3a-91c9adbd1d20 (old id 1884451)
date added to LUP
2011-04-20 09:17:23
date last changed
2017-09-24 03:12:41
@article{71b5e8c0-1fee-441b-8c3a-91c9adbd1d20,
  abstract     = {Water sorption calorimetry has been used for characterization of 2D hexagonally ordered mesoporous silica SBA-15. Experimental data on water sorption isotherm, the enthalpy, and the entropy of hydration of SBA-15 are presented. The results were compared with previously published results on MCM-41 obtained using the same technique. The water sorption isotherm of SBA-15 consists of four regimes, while the sorption isotherm of MCM-41 consists only of three. The extra regime in the water sorption isotherm for SBA-15 arises from filling of intrawall pores, that are present in SBA-15 but absent in MCM-41. The water sorption isotherms of the two types of mesoporous silica were analyzed using the Barrett-Joyner-Halenda approach. For the BJH analysis, t-curves of silica with different degrees of hydroxylation were proposed. Comparison of water and nitrogen t-curves shows that, independent of hydroxylation of silica surface, the adsorbed film of water is much thinner than the adsorbed film of nitrogen at similar relative pressures. This fact decreases the uncertainty of the assessment of porosity with water sorption originated from variations in surface properties. The pore size distribution of SBA-15 calculated with BJH treatment of water sorption data is in good agreement with nitrogen NLDFT results on the same material.},
  author       = {Kocherbitov, Vitaly and Alfredsson, Viveka},
  issn         = {0743-7463},
  language     = {eng},
  number       = {7},
  pages        = {3889--3897},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Assessment of Porosities of SBA-15 and MCM-41 Using Water Sorption Calorimetry.},
  url          = {http://dx.doi.org/10.1021/la103807v},
  volume       = {27},
  year         = {2011},
}