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

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• 作者：Man-Chien Chao ; Chia-Hsien Chang ; Hong-Ping Lin ; Chih-Yuan Tang and Ching-Yen Lin
• 刊名：Journal of Materials Science
• 出版年：2009
• 出版时间：December, 2009
• 年：2009
• 卷：44
• 期：24
• 页码：6453-6462
• 全文大小：719.1 KB

文摘

Pluronic 123-templated mesoporous SBA-15 silica rods with a length of ca. 3.0–4.0 μm 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 SO₄ 2− counterion from H₂SO₄ has higher affinity to induce the formation of P123 rod-like micelles than that of Cl−, NO₃ −. 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 S0¡¤¡¤¡¤I0 rather than the S0X−…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.