Effects of primary and secondary amines on the formation of hollow silica nanoparticles by using emulsion template method
Abstract This paper describes the amine effect on the sol gel synthesis which can rapidly form the shell structure of the hollow silica nanoparticles (HSNPs) Poly acrylic acid (PAA)/amine emulsion templates for the silica coating were formed in ethanol, and the emulsion templates were removed by water to obtain the HSNPs. To investigate of the ionic cross linker and catalyst abilities of the amine, four types of amines; i.e. ethylamine (EA) ethylenediamine (EDA) diethylenetriamine (DETA) and triethylenetetramine (TETA) were used. As a result, the HSNPs could be successfully synthesized with a high TEOS conversion ratio (95% and a shorter reaction time (2 h) by using EDA, DETA, and TETA. During this procedure, the amine worked as a catalyst for the sol gel reaction and an ionic cross linkers for PAA. As the catalyst ability, EDA was the most effective catalyst for the sol gel reaction that was measured by the zeta potential. Regarding the cross link ability, TETA worked as the most effective cross linker for the PAA condensation that was determined by the viscosity measurement. It showed that both the cross link ability and catalyst ability were important factors for this procedure. It was clarified that the HSNPs can be synthesized within a short time with a high conversion ratio by considering the PAA/amine solution viscosity and interaction of the amine with the alcohol.