In Situ Synthesis of the Hollow Silica Microspheres with Porous Surface by Using Chemical Modified Pollen Grains as Biotemplate

Hollow silica microspheres with porous surface were synthesized by using the pollen grains as biotemplate through an in-situ synthesis process, in which the pollen grains were surface modified by ammonium oleate. Scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption-desorption porosimetry analyzer were applied to investigate the as-prepared microspheres. Bovine serum albumin was used as the model drug to estimate the adsorption property. And the effect of the different amount of tetraethoxysilane during the synthesis process were discussed in this paper. Results indicated that the hierarchical network of the pollen wall could be well replicated through this method, in which the hydrophobic interaction between the pollen wall and surfactant as well as the electrostatic interaction between the surfactant and the hydrolysate of tetraethoxysilane were considered as the key factors for the replication. The hollow silica microspheres have loading capacity for the model drug, and the adsorption property of this microsphere could be easily adjusted by changing the amount of tetraethoxysilane.