Controlled release of paraquat from poly vinyl alcohol hydrogel

A thorough investigation on different controlled release systems were evaluated. The required devices were constructed simultaneously and the required experiments were performed. The polymeric network and membranes of poly vinyl alcohol with cross-linking agent glutaraldehyde for preparation of hyrogel system was effected. Paraquat, a type of herbicide was introduced as solute in the system. Glutaraldehyde was utilized as cross-linking agent at different concentration. Increase in the concentration of the cross-linking agent will cause a decrease in the extent of release out of the system. The effect of temperature on hydrogel adsorption demonstrates a higher adsorption at lower temperature. (C) 2002 Published by Elsevier Science B.V.