Fabrication of Novel Avermectin-porous Hollow Silica Nanoparticles (Av-PHSN) Carrier and Its Properties

Porous hollow silica nanoparticles (PHSN) with a diameter of ~100 nm and a pore size of ~4.5 nm were synthesized via a sol-gel route and using inorganic CaCO3 nanoparticles as templates. The as-synthesized PHSN were subsequently employed as novel pesticide carriers to study the controlled release behaviors of avermectin. The avermectin loaded PHSN (Av-PHSN) samples were characterized by BET, TG and IR. It showed that the encapsulation amount of avermectin in the PHSN carriers could reach 62.5% by a simple immersing loading method, and most adsorption of avermectin on the Av-PHSN carriers might be physical. Avermectin was released slowly into a bulk solution for about 2 000 minutes, thus exhibited a typical sustained release pattern without any burst effect. In addition, Av-PHSN carriers exhibited remarkable UV-shielding properties for avermectin. Therefore, it showed that the PHSN carriers have a promising future in applications of sustained pesticide release.