TY - JOUR
T1 - Effect of organic additives on the formation of alkylsiloxane mesophases
AU - Shimojima, Atsushi
AU - Sakurai, Mikako
AU - Kuroda, Kazuyuki
AU - Okubo, Tatsuya
PY - 2010/10/1
Y1 - 2010/10/1
N2 - The effects of organic additives (1,3,5-trialkylbenzenes, n-alkanes, and n-alkyl alcohols) on the formation of hybrid siloxane-organic mesophases from alkoxylated precursors (CnH2n+1Si(OSi(OMe)3)3, 1Cn, n=6, 10, and 16) have been investigated. These precursors become amphiphilic upon hydrolysis of the alkoxy groups, thus forming two-dimensional (2D) hexagonal phase (n=6 and 10) and lamellar phase (n=16) by evaporation-induced self-assembly followed by polycondensation. The addition of 1,3,5-trialkylbenzenes or n-alkanes to the 1C10 system leads to swollen 2D hexagonal phases, thereby achieving pore-size expansion of the calcined samples from 2.0nm up to 3.8nm in diameter. The effect of these organic additives depends largely on the alkyl chain length of 1Cn; the 2D hexagonal structure (n=6) undergoes structural disordering, while the lamellar structure (n=16) remains unchanged. On the other hand, the addition of alkyl alcohols to the 1C10 system causes a drastic change in the mesostructure from 2D hexagonal to lamellar, which can be attributed to possible interactions between alcohol molecules and silanol groups of hydrolyzed 1C10. These results provide a facile approach to the fine structural control of nanohybrid materials assembled from single siloxane-based molecules.
AB - The effects of organic additives (1,3,5-trialkylbenzenes, n-alkanes, and n-alkyl alcohols) on the formation of hybrid siloxane-organic mesophases from alkoxylated precursors (CnH2n+1Si(OSi(OMe)3)3, 1Cn, n=6, 10, and 16) have been investigated. These precursors become amphiphilic upon hydrolysis of the alkoxy groups, thus forming two-dimensional (2D) hexagonal phase (n=6 and 10) and lamellar phase (n=16) by evaporation-induced self-assembly followed by polycondensation. The addition of 1,3,5-trialkylbenzenes or n-alkanes to the 1C10 system leads to swollen 2D hexagonal phases, thereby achieving pore-size expansion of the calcined samples from 2.0nm up to 3.8nm in diameter. The effect of these organic additives depends largely on the alkyl chain length of 1Cn; the 2D hexagonal structure (n=6) undergoes structural disordering, while the lamellar structure (n=16) remains unchanged. On the other hand, the addition of alkyl alcohols to the 1C10 system causes a drastic change in the mesostructure from 2D hexagonal to lamellar, which can be attributed to possible interactions between alcohol molecules and silanol groups of hydrolyzed 1C10. These results provide a facile approach to the fine structural control of nanohybrid materials assembled from single siloxane-based molecules.
KW - Alkoxysilanes
KW - Amphiphilic molecules
KW - Inorganic-organic hybrids
KW - Mesophase
KW - Self-assembly
KW - Silica
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U2 - 10.1016/j.jcis.2010.06.013
DO - 10.1016/j.jcis.2010.06.013
M3 - Article
C2 - 20609446
AN - SCOPUS:77955319047
VL - 350
SP - 155
EP - 160
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
SN - 0021-9797
IS - 1
ER -