Preparation of Silica Hollow Microspheres with Special Surface Morphology by Biotemplate Method

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 replication 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.