Pore Structure Control of Silica Gels Based on Phase Separation
Pore Structure Control of Silica Gels Based on Phase Separation
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DOI：
10.1023/a:1009627216939
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发表时间：
1997-06-01
影响因子：
2.6
通讯作者：
Nakanishi, Kazuki
中科院分区：
文献类型：
--
作者：
Nakanishi, Kazuki
在烷氧基Sol-Gel体系中，通过诱导平行于Sol-Gel转变的相分离可以得到不同的大孔形貌。这种大孔形貌控制原理最适用于纯二氧化硅和二氧化硅基多组分氧化物体系。相分离发生得越早，气孔和凝胶骨架的特征尺寸越大。时间分辨光散射测量表明，凝胶的形态形成过程呈现调幅分解的特征，最终的凝胶形态是由相区粗化和结构冻结之间的竞争动力学决定的。这种大孔凝胶骨架的中孔结构可以很容易地通过溶剂交换过程来定制。具有可控大孔和中孔的硅胶被成功地用作连续棒状高效液相色谱柱的材料。
In the alkoxy-derived sol-gel system, various macroporous morphologies can be obtained by inducing the phase separation parallel to the sol-gel transition. This principle of macroporous morphology control can be best applied to pure silica and silica-based multicomponent oxide systems. The earlier the phase separation takes place than the sol-gel transition, the larger the characteristic sizes of pores and gel skeletons become. The time resolved light scattering measurements revealed that the morphology formation process exhibits the features of spinodal decomposition and that the final gel morphology is determined by the competitive kinetics between the domain coarsening and the structure freezing by sol-gel transition. The mesopore structure of such macroporous gel skeletons could be easily tailored by the solvent exchange procedures. Silica gels with controlled macropores and mesopores were successfully applied as a material for the continuous rod type column for high performance liquid chromatography.