TY - JOUR
T1 - Microwave-hydrothermal synthesis and characterization of microporous-mesoporous disordered silica using mixed-micellar-templating approach
AU - Newalkar, Bharat L.
AU - Katsuki, Hiroaki
AU - Komarneni, Sridhar
N1 - Funding Information:
Authors gratefully acknowledge the support of this work by the NSF MRSEC program under grant number, DMR-0080019.
PY - 2004/9/6
Y1 - 2004/9/6
N2 - The present investigation reports a mixed micellar supramolecular templating approach to obtain microporous-mesoporous silica frameworks having textural characteristics close to supermicroporous frameworks under microwave-hydrothermal conditions. The crystallization of such frameworks was achieved by templating a silica precursor with a mixed micellar system, comprising of pluronic123 copolymer (EO20PO70EO 20; M.W. 5800) and cationic surfactants (n-Decyltrimethyl ammonium bromide/Dodecyltrimethyl ammonium bromide/Hexadecyltrimethyl ammonium bromide) at 373 K. The crystallized materials were characterized by means of powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and nitrogen adsorption measurements at 77 K. Furthermore, the existence of supramolecular templating phenomenon in the formation of porous silica was established by performing the crystallization in the presence of a swelling agent (mesitylene). The X-ray diffraction patterns for calcined samples exhibited low angle peaks with interplanar spacings in the range of 2.7-3.2 nm. The specific BET surface area values for various samples, based on nitrogen adsorption data, were found to be in the range of 740-953 m2 g -1 whereas pore volumes for the crystallized samples were found to vary in the range of 0.35-0.52 cm3g-1.
AB - The present investigation reports a mixed micellar supramolecular templating approach to obtain microporous-mesoporous silica frameworks having textural characteristics close to supermicroporous frameworks under microwave-hydrothermal conditions. The crystallization of such frameworks was achieved by templating a silica precursor with a mixed micellar system, comprising of pluronic123 copolymer (EO20PO70EO 20; M.W. 5800) and cationic surfactants (n-Decyltrimethyl ammonium bromide/Dodecyltrimethyl ammonium bromide/Hexadecyltrimethyl ammonium bromide) at 373 K. The crystallized materials were characterized by means of powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and nitrogen adsorption measurements at 77 K. Furthermore, the existence of supramolecular templating phenomenon in the formation of porous silica was established by performing the crystallization in the presence of a swelling agent (mesitylene). The X-ray diffraction patterns for calcined samples exhibited low angle peaks with interplanar spacings in the range of 2.7-3.2 nm. The specific BET surface area values for various samples, based on nitrogen adsorption data, were found to be in the range of 740-953 m2 g -1 whereas pore volumes for the crystallized samples were found to vary in the range of 0.35-0.52 cm3g-1.
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U2 - 10.1016/j.micromeso.2004.05.002
DO - 10.1016/j.micromeso.2004.05.002
M3 - Article
AN - SCOPUS:12744261899
VL - 73
SP - 161
EP - 170
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
IS - 3
ER -