Self-assembly of phosphorylated poly(ethyleneimine) for use as biomimetic templates in the formation of hybrid hollow silica spheres

The submicron scale hybrid hollow silica spheres have been fabricated by employing phosphorylated polyethyleneimine as template/scaffold/catalysis in a mild self-assembly biomineralization approach. The highly phosphorylated polyethyleneimine was shown to be a necessary prerequisite for in vitro formation of hollow silica spheres. In the presence of a neutral phosphate buffer, the monovalent anions H PO and divalent anions HPO acted not only as the buffer ions but also as ligands, regulating the shape and morphology of the PEI aggregation, which resulted in the final hollow morphology of silica. The hollow silica particles were very uniform in size, with a diameter of 0.8-1.0 μm and a shell thickness of ~ 70 nm.