Abstract:

A non-ionic and poorly water-soluble pesticide, pyridaben, was intercalated into the gallery of layered double hydroxides (LDHs) using coprecipitation method in ethanol-water mixed solvent medium, obtaining pyridaben-LDHs hybrids. According to the gallery height of pyridaben-LDHs and sizes of pyridaben molecule, a probably morphology of pyridaben molecules in the gallery of LDHs was suggested that pyridaben molecules arranged as monolayer with the long axis tilted to the LDHs layers. The release kinetics of pyridaben from the hybrids was investigated in ethanol-water solution, and it was found that the release process may fit to the pseudo-second-order release kinetics and the diffusion through the LDHs particle of pyridaben played an important role in controlling the drug release rate. The hybrids could control the release of pyridaben, showing that the hybrids will be a potential pesticide controlled-release formulation.

Key words:  layered double hydroxides; pyridaben; hybrids; controlled release; pesticide