TY - JOUR
T1 - Energetics of mesoporous silica
T2 - Investigation into pore size and symmetry
AU - Trofymluk, Olga
AU - Levchenko, Andrey A.
AU - Tolbert, Sarah H.
AU - Navrotsky, Alexandra
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2005/7/12
Y1 - 2005/7/12
N2 - Two families of calcined highly ordered mesoporous silicas, designed as M41S (MCM-41 and MCM-48) and SBA-n (SB A-15 and SB A-16), are investigated in a wide range of pore sizes from 2.1 to 26.4 nm by high-temperature oxide melt solution calorimetry using lead borate solvent at 974 K. These data are consistent with and extend our earlier studies of zeolite microporous and of mesoporous silicas. The formation enthalpies observed are 19.0-31.4 kJ/mol less exothermic than that of quartz and correlate linearly with pore size for a given structure type. Small- and wide-angle X-ray scattering, nitrogen adsorption (BET), thermogravimetric analysis, and 29Si NMR are employed to give insight into structure and symmetry. The enthalpy differences among samples are discussed in terms of symmetry and structural (point and ring) defects in the materials.
AB - Two families of calcined highly ordered mesoporous silicas, designed as M41S (MCM-41 and MCM-48) and SBA-n (SB A-15 and SB A-16), are investigated in a wide range of pore sizes from 2.1 to 26.4 nm by high-temperature oxide melt solution calorimetry using lead borate solvent at 974 K. These data are consistent with and extend our earlier studies of zeolite microporous and of mesoporous silicas. The formation enthalpies observed are 19.0-31.4 kJ/mol less exothermic than that of quartz and correlate linearly with pore size for a given structure type. Small- and wide-angle X-ray scattering, nitrogen adsorption (BET), thermogravimetric analysis, and 29Si NMR are employed to give insight into structure and symmetry. The enthalpy differences among samples are discussed in terms of symmetry and structural (point and ring) defects in the materials.
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U2 - 10.1021/cm050366g
DO - 10.1021/cm050366g
M3 - Article
AN - SCOPUS:22944469384
VL - 17
SP - 3772
EP - 3783
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 14
ER -