The transformation of mesoporous silica morphology from monoliths to spherical particles was investigated at room temperature in Pluronic F127/TEOS system as a function of HCl acid catalyst concentration to understand and control the mechanism. It is shown that the specific surface area and the size of mesoporous spherical silica particles can simply be adjusted by the catalyst concentration without using any additives or post-treatment.

Above 3 M acid concentration, novel monodisperse micron sized spherical silica with hierarchical order of two levels was obtained. These silica spheres were formed of densely packed distorted hexagonal platelets of 20–30 nm in diameter. Within these platelets mesoporous channels were oriented along a single direction, however the platelets were randomly oriented in the spherical particles. Controlling the agglomeration of mesoporous silica primary particles by the concentration of the acid catalyst to obtain micron-sized spherical particles is novel. This approach allows the synthesis of particles whose sizes can be controlled in the range of ~1–4 μm and specific surface area in the range of ~200–500 m²/g.

The morphology of the particles transforms from spherical shape to mesoporous monoliths at acid concentrations below 1 M due to slow hydrolysis and condensation. These results are important in understanding the role of catalyst concentration on the formation mechanism of different morphologies of mesoporous silica.

在室温下，研究了Pluronic F127 / TEOS系统中介孔二氧化硅形态从整体结构向球形颗粒的转变与HCl酸催化剂浓度的关系，以了解和控制其机理。结果表明，介孔球形二氧化硅颗粒的比表面积和尺寸可以简单地通过催化剂浓度来调节，而无需使用任何添加剂或进行后处理。

在酸浓度高于3 M时，获得了具有两个等级层次的新型单分散微米级球形二氧化硅。这些二氧化硅球是由直径20–30 nm的密堆积扭曲的六角形血小板形成的。在这些血小板中，中孔通道沿单个方向取向，但是血小板在球形颗粒中随机取向。通过酸催化剂的浓度控制中孔二氧化硅初级颗粒的附聚以获得微米尺寸的球形颗粒是新颖的。这种方法可以合成粒径可以控制在约1-4μm范围内，比表面积在约200-500 m ² / g范围内的颗粒。

在1 M以下的酸浓度下，由于缓慢的水解和冷凝作用，颗粒的形态从球形转变为中孔整料。这些结果对于理解催化剂浓度对中孔二氧化硅不同形态的形成机理的作用是重要的。