Amine-functionalized polysilsesquioxane hollow nanospheres for pH-responsive pesticide release system with UV-shielding property

Polysilsesquioxane (PSQ) hollow spheres show great potential in various fields, including catalysts, environmental protection, and drug delivery, owing to their high stability, large interior cavity, and adjustable surface chemistry. However, the fabrication of amino-functionalized PSQ hollow spheres (AHPSQ) with inherent amine groups on the surface still remains a challenge partly due to the hydrophilicity of the silane precursor. In this study, for the first time AHPSQ was fabricated via a facile sol-gel process utilizing aminopropyltrimethoxysilane and methyltrimethoxysilane as co-precursor in an ice bath. The pH-sensitive release behavior of AHPSQ was demonstrated using avermectin as a pesticide model and the release kinetics were analyzed. The artificial ultraviolet accelerated experiment confirmed that the carrier has an ultraviolet protective effect on the pesticide and can reduce the ultraviolet degradation rate.