title: Controlled release of avermectin from porous hollow silica nanoparticles.
abstract: Porous hollow silica nanoparticles (PHSNs) with a diameter of ca 100 nm and a pore size of ca 4.5 nm were synthesized via a sol-gel route using inorganic calcium carbonate nanoparticles as templates. The synthesized PHSNs were subsequently employed as pesticide carriers to study the controlled release behaviour of avermectin. The avermectin-loaded PHSN (Av-PHSN) samples were characterized by BET, thermogravimetric analysis and IR, showing that the amount of avermectin encapsulated in the PHSN carrier could reach 58.3% w/w by a simple immersion loading method, and that most of the adsorption of avermectin on the Av-PHSN carrier might be physical. Avermectin may be loaded on the external surface, the pore channels in the wall and the inner core of the PHSN carriers, thus leading to a multi-stage sustained-release pattern from the Av-PHSN samples. Increasing pH or temperature intensified the avermectin release.
authors.affiliation: Key Laboratory for Nanomaterials, Ministry of Education, Research Centre of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Li-Xiong
authors.initials: LX
authors.lastname: Wen
authors.forename: Zhu-Zhu
authors.initials: ZZ
authors.lastname: Li
authors.forename: Hai-Kui
authors.initials: HK
authors.lastname: Zou
authors.forename: An-Qi
authors.initials: AQ
authors.lastname: Liu
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Chen
mesh_terms: D003692:Delayed-Action Preparations; D006863:Hydrogen-Ion Concentration; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000737:chemistry*; D049329:Nanostructures; D010575:Pesticides / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D010575:Pesticides; D007559:Ivermectin; C019264:avermectin; D012822:Silicon Dioxide