TY - JOUR
T1 - Development and sorption characterization of some model mesoporous and microporous silica adsorbents
AU - Esparza, J. M.
AU - Ojeda, M. L.
AU - Campero, A.
AU - Hernández, G.
AU - Felipe, C.
AU - Asomoza, M.
AU - Cordero, S.
AU - Kornhauser, I.
AU - Rojas, F.
PY - 2005/3/16
Y1 - 2005/3/16
N2 - Mesoporous and microporous silica substrates, each of these kinds endowed with unique textural characteristics, have been prepared via sol-gel and micelle-templating techniques and characterized through N2 sorption. Materials consisting of a lattice of cage-like monodisperse cavities interconnected by narrow throats (SBA-16), a set of individual cylindrical pores of about the same size (SBA-15), a network of long sinuous ganglion-like sequences of bulges and throats (mesoporous glass, MG), or microporous arrangements of globular nanoparticles (microporous SiO2) have been developed. The N2 sorption isotherms of microporous silica at 76 K correspond to International Union of Pure and Applied Chemistry (IUPAC) type I, while those of mesoporous SBA-16, SBA-15, and MG silica match a type IV with hysteresis loops of types H1 or H2 depending on the regularity and nature of the void elements constituting the substrate. A characteristic common to all kinds of porous SiO2 solids herein synthesized is the rigidity of the arrangements, since the total pore volumes attain limiting values. Pore-size distributions of mesoporous SiO2 materials can be calculated by density functional theory (DFT) and sometimes by Barrett-Joyner-Halenda (BJH) methods. The microporous SiO2 adsorbent depicts a larger amount of big micropores (supermicropores) rather than small micropores (ultramicropores), this being a very useful characteristic for the entrapment and ulterior release of volatile compounds. MG substrates depict a percolation vapor threshold while the SBA-16 material shows a cavitation phenomenon during capillary evaporation. Additional properties of SBA-16, SBA-15, MG silica substrates are studied via primary desorption scanning curves.
AB - Mesoporous and microporous silica substrates, each of these kinds endowed with unique textural characteristics, have been prepared via sol-gel and micelle-templating techniques and characterized through N2 sorption. Materials consisting of a lattice of cage-like monodisperse cavities interconnected by narrow throats (SBA-16), a set of individual cylindrical pores of about the same size (SBA-15), a network of long sinuous ganglion-like sequences of bulges and throats (mesoporous glass, MG), or microporous arrangements of globular nanoparticles (microporous SiO2) have been developed. The N2 sorption isotherms of microporous silica at 76 K correspond to International Union of Pure and Applied Chemistry (IUPAC) type I, while those of mesoporous SBA-16, SBA-15, and MG silica match a type IV with hysteresis loops of types H1 or H2 depending on the regularity and nature of the void elements constituting the substrate. A characteristic common to all kinds of porous SiO2 solids herein synthesized is the rigidity of the arrangements, since the total pore volumes attain limiting values. Pore-size distributions of mesoporous SiO2 materials can be calculated by density functional theory (DFT) and sometimes by Barrett-Joyner-Halenda (BJH) methods. The microporous SiO2 adsorbent depicts a larger amount of big micropores (supermicropores) rather than small micropores (ultramicropores), this being a very useful characteristic for the entrapment and ulterior release of volatile compounds. MG substrates depict a percolation vapor threshold while the SBA-16 material shows a cavitation phenomenon during capillary evaporation. Additional properties of SBA-16, SBA-15, MG silica substrates are studied via primary desorption scanning curves.
KW - Mesoporous glass
KW - Microporous SiO
KW - SBA-15
KW - SBA-16
KW - Vapor percolation
UR - http://www.scopus.com/inward/record.url?scp=12844276117&partnerID=8YFLogxK
U2 - 10.1016/j.molcata.2004.09.042
DO - 10.1016/j.molcata.2004.09.042
M3 - Artículo
AN - SCOPUS:12844276117
SN - 1381-1169
VL - 228
SP - 97
EP - 110
JO - Journal of Molecular Catalysis A: Chemical
JF - Journal of Molecular Catalysis A: Chemical
IS - 1-2 SPEC. ISS.
ER -