Immobilization of herbicide metazachlor in hydrogel microcapsules.

摘要

The herbicide metazachlor was incorporated in alginate-based hydrogel microcapsules to obtain controlled release properties. Sodium alginate as a 1.5% solution was used to obtain a hydrogel matrix. Three concentrations of metazachlor, two solvents and a mixture of ethyl acetate/vegetable oil were used for the microcapsule preparation. All the hydrogel microcapsules of metazachlor were stored in distilled water and two surface water samples at two temperatures, 5 and 20 degrees C. The capsules were characterized mechanically after one day, following 1 and 6 weeks of storage. The mechanical resistance of the microcapsules was determined on testing machine Zwick Roell Z 2.5 (Germany). Most of the microcapsules showed a good mechanical stability during storage in distilled water at low temperature.