【摘要】 介孔材料的合成通常以表面活性剂自组装体为有机模板剂,并以高温焙烧法除去形成介孔结构中的有机模板.提出了一种全新的湿氧化去除介孔二氧化硅材料中的有机模板剂的方法,即以食人鱼溶液（3H₂SO₄-H₂O₂）处理含模板剂的MCM-41和SBA-15 2种典型的介孔材料,并对比研究了高温焙烧法和湿氧化法脱除有机模板剂的效果.通过XRD、FT-IR、N₂吸脱附、SEM、TG等手段对脱除模板剂前后的介孔材料进行表征.结果表明:食人鱼溶液可有效脱除介孔材料中的有机模板剂,且能很好地保留介孔结构;相比于高温焙烧后的样品,湿氧化法脱除模板剂后的样品具有更大的比表面积和更丰富的硅羟基,并克服了高温焙烧脱除模板剂造成的骨架收缩.更多还原

【Abstract】 Mesoporous materials were often synthesized by using the self-assemblies of surfactant as organo-template. Calcination was a typical method for the removal of the organo-template from the as-synthesized mesostructure. A new wet oxidization method was introduced to remove organo-template from the mesoporous silicas. Specifically, two typical as-synthesized mesoporous silica materials of MCM-41 and SBA-15 were treated by a mixture of H₂SO₄ and H₂O₂（called piranha solution）. A comparison study was made on the effect of the calcination and the wet oxidization on the removal of the organo-template. Various techniques such as X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FT-IR）, N₂ adsorption-desorption, scanning electronic microscope（SEM） and thermogravity（TG） etc. were used to characterize the as-synthesized and treated mesoporous materials. The results showed that the piranha solution could efficiently remove the organo-template from the mesoporous materials, while preserving the mesostructure. The samples treated with the piranha solution exhibit larger specific surface areas and more silanols compared to those calcined at high temperatures. Additionally, the shrinkage issue of the mesostructure in the calcination process was conquered during the removal of the organo-template by the wet oxidization method.更多还原