Controlled Release Systems Based on Intercalated Paraquat onto Montmorillonite and Clinoptilolite Clays Encapsulated with Sodium Alginate

ABSTRACT As a model herbicide, paraquat (PQ) was intercalated into montmorillonite (MMT) and clinoptilolite (CL) clays at different concentrations. FT‐IR, XRD, and SEM techniques were used to characterize the structures of the prepared formulations. The prepared PQ/clay samples were further encapsulated with alginate (Alg) polymer. After characterization, the potential application was verified through release of PQ from PQ/clay and PQ/clay/Alg formulations. According to the results, the release of PQ from PQ/MMT was slower than the release from the PQ/CL system. The presence of the alginate polymer in PQ/clay/Alg capsule beads caused the system to liberate PQ in a more controlled release manner than PQ/clay samples. Furthermore, the release data were fitted to empirical equations to estimate the kinetic parameters. The results suggested the feasibility of the use of clay/Alg formulations for controlled release of herbicides in agricultural applications.