parameters affecting the migration of metal ions from crosslinked Pva polymer

in the field of agriculture, the release of different metal ions from some polymeric material has a large area of applications. polymers such as polyvinyl alcohol (Pva) can be used in many directions, for instance, in the field of drug delivery or controlled release systems . in this work strips of constant thickness and area of Pva, loaded with different metal ions such as (Cu, Co, Ni), have been irradiated by gamma rays to 50 kGy, for inducing crosslinking . Pva strips were evaluated for controlled release of heavy metal ions to the soil so that it must be below the toxicity level . the leached amount was determined by UV spectroscopic method. the parameters which affect the leached amount, such as concentration of metals in Pva , type of water, leaching time, temperature of the environment and the surface areas of Pva strips, were evaluated. it was found that, the amount of leached metal ions was increased by increasing their concentration in the parent polymer, increasing Ph value, temperature as well as surface area. Also , it has been noticed that the leached amount of different metal ions from Pva has the following order: Ni++> Co++> Cu++. structural morphology of Pva loaded with different metal ions was investigated by means of Sem. the scanning electron micrographs illustrates a number of folds on the surface of the sample after metal release. the release of heavy metal ions to the soil by using crosslinked Pva loaded with these metal ions may be applied in agricultural domain