Fundamental method for controlling monodisperse silica nanoparticles dimension assisted by lysine

In this paper, we report the fundamental method for controlling monodispersed silica nanoparticles size ranged from 10 to ~135 nm assisted by lysine or lysine hydrochloride, during which the seed regrowth technique was utilized. The synthesis was prepared in the water-base system, which was environment friendly and convenient. According to our research, the influence factors of co-solvent system, molar content of additional TEOS, and molar ratio composition of additional TEOS/seeds were confirmed. The final morphology and size of silica nanoparticles can be tuned by changing the amount of additional TEOS and the seeds size. To guarantee the monodispersity of final particles. In the regrowth process, cyclohexane used as the co-solvent floated on the surface of water to block additional TEOS contact with water directly, and made the silicate intermedium consumable for the growth of the parent particles immediately, while not forming new nucleation. In such a condition, to lower the cost and prepare mass production, the lysine was replaced by lysine hydrochloride, meanwhile, triethylamine was introduced to neutralize the hydrochloride. It should be noted that as the particle size increased to be more than 100 nm, when usinglysine hydrochloride and triethylamine, the types of nitrogen adsorption–desorption isotherms changed from H1 to H3; in contrast, the isotherms of the particles were changed from H2 to H1 when catalyzed by lysine.