Particulate Fluids Processing Centre, School of Chemistry, The University of Melbourne , Melbourne VIC 3010, Australia.
Langmuir. 2011 Mar 15;27(6):2124-7. doi: 10.1021/la104738p. Epub 2011 Feb 1.
Mesoporous silica pellets with controllable shape and pore size were prepared using agarose gel templates. Robust (compressive strength of 3.3-25.1 MPa), crack-free silica monoliths have been produced with large mesopores (14-23 nm), high surface areas (410-540 m(2) g(-1)), and large pore volumes (1.1-1.2 cm(3) g(-1)). The synthesis was achieved by infusing preformed agarose gels with tetraethyl orthosilicate and the nonpolar condensation catalyst tetrabutyl ammonium fluoride. The infiltrated gels were transferred to water to initiate hydrolysis and condensation of the silica precursor. Fluoride catalyzed the gelation of silica in a matter of minutes; hence, the oxide maintained the shape of the agarose pellet. The mesopore size could be modified by altering the weight percent of agarose gel used. The method employed here is simple and reproducible. As these materials have such large mesopore dimensions, they could be used as hard templates or could be specifically functionalized for use in environmental remediation, as environmentally responsive materials, biocatalysts, or catalysts.
采用琼脂糖凝胶模板制备了具有可控形状和孔径的介孔硅球。已制备出具有大介孔（14-23nm）、高表面积（410-540m2/g）和大孔体积（1.1-1.2cm3/g）的坚固（抗压强度为 3.3-25.1MPa）、无裂纹的二氧化硅整体材料。通过将预制的琼脂糖凝胶注入正硅酸乙酯和非极性缩合催化剂四丁基氟化铵来实现合成。将浸渍的凝胶转移到水中以引发硅烷前体的水解和缩合。氟化物在几分钟内催化了二氧化硅的胶凝，因此氧化物保持了琼脂糖小球的形状。通过改变使用的琼脂糖凝胶的重量百分比，可以改变介孔尺寸。这里采用的方法简单且可重复。由于这些材料具有如此大的介孔尺寸，它们可用作硬模板，或者可以专门官能化用于环境修复、作为环境响应材料、生物催化剂或催化剂。
