利用油菜花粉作为生物模板,通过溶胶在花粉颗粒表面包裹,再经高温烧结去除花粉颗粒的方法制备了具有特殊表面形貌的二氧化硅中空微球.并通过调节溶胶中醇盐与水的比例,实现了不同表面形貌的二氧化硅中空微球的制备.利用差热(DSC)、热重(TG)、X射线能谱仪(EDS)、扫描电子显微镜(SEM)等对花粉颗粒和所制备的二氧化硅中空微球进行了表征,并对不同表面形貌的形成机理进行了探讨.结果表明,花粉内壁在200℃时即可完全消除,从而形成中空结构,而外壁及其表面的网格状结构在较高温度仍能保持完好,从而保证该结构在微球表面的复制,而溶胶浓度则是形成微球表面不同形貌的决定因素,随着胶体粒子在花粉表面沉积量的不同,微球表面的微孔结构也将随之变化.
Surface structured silica hollow microspheres were synthesized using the rape pollen grain as a biotemplate via a facile sol-gel method and a succedent calcinations process. Different surface morphologies were also achieved on the as-prepared silica microspheres by changing the ratio of tetraethyl orthosilicate (TEOS) to water in the silica sols. Differential scanning calorimetry (DSC), thermogravity (TG), energy disperse spectroscope (EDS) and scanning electron microscope (SEM) were used to characterize the pollen grain and the as-prepared silica hollow microspheres. The mechanism of morphology controlling in the microspheres fabrication was discussed in detail. The results indicate that the intine of pollen grain will be removed totally at 200℃, as a consequence hollow structure can be achieved in pollen grain, And the exine of pollen grain with the net-like morphology can be maintained under higher temperature, which makes the rep- lication of the microstructure on microspheres surface possible. Along with quantity of colloidal particles deposited on pollen grain, the special surface morphology on the silica hollow microspheres will be adjustable.