Morphological control on SBA-15 mesoporous silicas via a slow self-assembling rate

作者：Chao Man Chien; Chang Chia Hsien; Lin Hong Ping^*; Tang Chih Yuan; Lin Ching Yen

来源：Journal of Materials Science, 2009, 44(24): 6453-6462.

DOI：10.1007/s10853-009-3610-9

Pluronic 123-templated mesoporous SBA-15 silica rods with a length of ca. 3.0-4.0 mu m were easily synthesized in a dilute silicate solution with a pH value of 2.0 at room temperature. Through a good control on the synthetic condition and the chemical components, a high homogeneity (> 95%) of the hexagonal SBA-15 silica rods can be achieved. In addition, the effect of the synthetic conditions including acid source, weight ratio of the P123/sodium silicate, temperature, water content, pH value, and applying shearing flow were explored in detail to tailor the morphologies of the SBA-15 mesoporous silicas. In this paper, we also focused on the counterion effect on the synthesis of the SBA-15 mesoporous silicas. It was found that the SO(4) (2-) counterion from H(2)SO(4) has higher affinity to induce the formation of P123 rod-like micelles than that of Cl(-), NO(3) (-). Meanwhile, we postulated that the self-assembly pathway of the silica species and the neutral tri-block copolymer micelles in a dilute solution with a pH value of 2.0 would occur through an S(0)center dot center dot center dot I(0) rather than the S(0)X(-aEuro broken vertical bar)I(+) one as previously discussed. We further employed the SAB-15 mesoporous silica rods as the templates to synthesize high-quality CMK-3 mesoporous carbon rods by using commercially available phenol-formaldehyde (PF) resin as the carbon source.

• 出版日期2009-12