三维规则排列的大孔钛硅混合氧化物的制备与表征

Synthesis and Characterization of Three-Dimensionally Ordered Macroporous (3DOM) Titania-Silica Mixed Oxides

以聚苯乙烯微球离心后形成的三维规则排列的胶晶作模板,用钛酸丁酯和正硅酸乙酯分别和水、乙醇等配制成的混合溶胶填充微球之间的间隙,然后原位形成凝胶,最后通过焙烧(<5℃/min;300℃,5h;570℃,5～10h,空气流速1L/min)除去微球得到三维规则排列的大孔钛硅混合氧化物.样品表面可观察到五颜六色的彩光.样品的SEM图表明,球形孔大小均匀,排列整齐,孔壁填充完全.孔径在500nm左右,孔的排列呈面心立方结构,孔与孔之间由小孔窗相互交连.较高的溶胶浓度有利于溶胶的填充,容易形成孔壁较厚的坚固的三维骨架.低浓度得到的样品孔壁薄,缺陷多,易脆裂.样品的EDS表明Si/Ti的摩尔比为2.7,XRD研究表明孔壁具有无定形的结构.

Three-Dimentionally Ordered macroporous titanium-silica mixed oxides were successfully synthesized by using polystyren sphere colloid crystal as the template and the sol of tetraethyl silicate and tetrabutoxy-titane as the filling fluid. The sol filled in the voids among spheres by capillary forces, and then transformed into gel in situ. Latex spheres were removed by calcination(<5&DEG;C/min; 300&DEG;C,5h; 570&DEG;C, 5h). The macroporous samples show a beautiful iridescence in reflected light. SEM indicates that the pores axe about 500nm in size and arrayed periodically in a face-centered cubic (fcc) structure and connected with each other by small windows. EDS indicates that the Si/Ti molar ratio is 2.7. XRD indicates the wall of the pores is amorphous.