窄孔分布介孔分子筛MSU-1的合成

以水玻璃为硅源，在pH=3以下合成MSU-X介孔材料的报道很少，本文将pH范围扩展至0.78，并从廉价的水玻璃和工业级非离子表面活性剂AEO-9出发，用二步法合成出介孔分子筛MSU-1。首先将无机前驱体和非离子表面活性剂在介稳态下(pH≈2，t≈2 ℃)混合，然后调pH至所需值(0.78～3.94)，在该pH值下进行二氧化硅缩聚。合成出的MSU-1具有孔分布窄，短程有序度提高，颗粒呈微米级等特点。其中在pH=1.98下合成的MSU-1具有最薄的孔壁、最大的比表面和孔容；在pH=0.78下合成的MSU-1具有最厚的孔壁、最大的孔径和d100值。随着pH值的增大，孔壁厚度先减小后增大。

SYNTHESIS OF MESOPOROUS MSU-1 SILICA WITH NARROW PORE SIZE DISTRIBUTION

The synthesis of MSU-X below pH 3 using sodium silicate solution as silica source has rarely been reported. In the present work, the range of pH value has been extended to about 0.78. Mesoporous MSU-1 silica has been readily synthesized from inexpensive sodium silicate solution and commercial non-ionic surfactant (AEO9) by the so-called two-step method. Firstly, the inorganic precursor and nonionic surfactant solution at the metastable state (pH2～pH*#3, t=2*#℃) were assembled and then the silica polycondensation was induced by adjusting pH of the reaction solution (pH 0.78～3.94). The products exhibit narrow pore distribution, enhanced short-range order mesoporous structure and micrometric particles. The sample prepared atpH 1.98 has the thinnest pore wall, the largest specific surface area and pore volume, while that synthesized at pH 0.78 has the thickest pore wall, the largest pore diameter and d100 value. The pore wall thickness of products decreases at first and then increases with pH increrase.