Study On Preparation And Release Of Diazinon And Imidacloprid Sustained Release Granules

It is an effective strategy that people use controlled-released formulations to improve the efficiency of pesticides and reduce the environmental pollution, the work use modifier to prepare a series of organic bentonite, and characterizes the structural characterization of organic bentonite, studies the adsorption properties of organic bentonite to diazinon in equilibrium and non equilibrium state, analyzes the adsorption mechanism and the influence factors of diazinon on organic bentonite. Prepare the sustained-release granules of diazinon, and analyzes the release behavior of diazinon from granules in water, researches the structural characterization of organic bentonite to the influence mechanism of release kinetics of diazinon from organic bentonite. At the same time, the work, as comparison, also utilizes the DTMAC and HTMAC as modification to prepare a series of organic bentonite, and researches the isothermal adsorption of imidacloprid, analyzes the adsorption mechanism and the influence factors of imidacloprid on organic bentonite. In addition, add sodium alginate to imidacloprid-organic bentonite to prepare imidacloprid-alginate organic bentonite granules and characterizes the granules, analyzes the water swelling of imidacloprid-alginate organic bentonite granule. Simultaneously the paper analyzes the release behavior of imidacloprid from granules in water, researches the structural characterization of organic bentonite to the influence mechanism of release kinetics of imidacloprid from organic bentonite. The main results are following:1> Comparison with the raw bentonite, organic bentonite greatly heighten the adsorption capacity of diazinon. And greatly delayed the release rate of diazinon in water. Influences on the quantity of laden quaternary ammonium salt to the adsorption property of organic bentonite are relevant to the load mechanism of bentonite. Load is lower1.0CEC, the quaternary ammonium salt is mainly adsorbed to the bentonite interlayer domain by ion exchange.With the amount of quaternary ammonium salt increasing, the adsorption capacity and controlled-release of organic bentonite for diazinon and imidacloprid are strengthened. With the further increase of load, the part of quaternary ammonium salt whose quantity are exceeded cation exchange capacity enter into the bentonite interlayer domains in molecular form and are adsorbed on its surface. It will compete with diazinon molecules in the process of adsorption. Besides, it reduces the hydrophobicity of bentonite interlayer domain and adsorption capacity. Sustained load quaternary ammonium salt has little effect on slow release diazinon. 2、The imidacloprid have strong polarity. No matter the short carbon chain organic bentonite or long carbon chain organic bentonite, exposed siloxane surface has stronger adsorption than hydrocarbon groups. Extension the lengths of carbon chain of quaternary ammonium salt as modifier enhances the adsorption coefficient with the organic bentonite to imidacloprid, but reduces the standard carbon adsorption coefficient. Imidacloprid-alginate-organic bentonite granules release studies in water show that the organic bentonite and sodium alginate can make the burst effect is reduced, the granules can slow release of imidacloprid in the water, retard the release rate of imidacloprid.