高度有序介孔氧化硅材料SBA-15：高浓度氨基官能化及氨基及氨基团的可利用性

采用简单的方法合成高浓度氨基修饰的高度有序氧化硅材料并深入研究氨基官能化材料的孔结构以及氨基的存在状态和可利用性。结果表明，氨基基团共价连接到SBA-15的孔表面，即使初始合成体系中的APTES（氨丙基三乙氧基硅烷）浓度高达30mol%时材料依然保持高度的有序性。合成体系中APTES浓度为20％的样品还保持良好的介孔结构，比表面积为680 m²·g^-1，孔容为0.89 cm³·g^-1，此介孔结构中的氨基官能团对镍离子表现出很强的亲和力，Ni²⁺的吸附量高达1.88 mmol·g^-1，相比之下未官能化的SBA-15对Ni²⁺没有吸附作用。当初始合成体系中APTES的浓度进一步增大到30％时，修饰到介孔氧化硅材料的氨基含量也随之增大，但由于材料的孔隙度急剧降低，这些氨基的可利用性也降低。

Highly Ordered Mesoporous Silica SBA-15 Functionalized with High Concentration of Amino Groups Accessible to Metal Ions

A facile strategy was used to synthesize highly ordered mesoporous silica SBA-15 functionalized with high concentration of amino groups, which seems to be rather difficult to be incorporated into mesoporous silica without disrupting the ordered mesoscopic structure compared to other functional groups. The pore structure of functionalized materials, together with the presence and accessibility of functional groups, were investigated in detail. It is shown that amino groups are attached covalently to the pore wall of SBA-15 and the ordered mesoscopic architecture of the functionalized samples remains almost intact even with a large concentration of aminopropyltriethoxysilane (APTES) up to 30mol% in the initial synthetic mixture. The samples with 20mol% takes place with unfunctionalized mesoporous silica. The amount of amino groups incorporated increase as the APTES concentration further increases to 30mol%, but the amino groups are less accessible due to the dramatic decrease in the porosity of functionalized samples.