High-surface-area disperse silica nanoparticles prepared via sol-gel method using L-lysine catalyst and methanol/water co-solvent

Abstract

Nanoglass microstructure is regarded as a potential strategic approach to give brittle glasses good toughness. For the preparation of SiO2 nanoglass, disperse ultrafine amorphous SiO2 nanoparticles with high surface area should be synthesized in advance. Herein, fully disperse ultrafine amorphous SiO2 nanoparticles were fabricated by sol-gel method and calcination. In the preparation, tetraethyl orthosilicate (TEOS) was used as silicon source, methanol/water as co-solvent, and basic amino acids as catalyst. By using l-lysine as a relatively moderate catalyst and methanol/water co-solvent, SiO2 nanoparticles were refined and their aggregation was eliminated. Under the optimal conditions of 0.27 mol/L TEOS, methanol/water co-solvent of a volume ratio of 1:1, and 5.40 mmol/L l-lysine, disperse amorphous SiO2 nanoparticles of 6.4 nm average particle size, 2−11 nm size distribution, and 386 m2/g specific surface area were synthesized. Our 6.4 nm SiO2 nanoparticles represent the highest-dispersity, finest-size, and highest-surface-area amorphous SiO2 nanoparticles so far.