Fabrication of hydrogel controlled-released Phosphorus encapsulated in starch-polyvinyl alcohol film

Abstract

Traditional soluble phosphorous(P) fertilizers can easily leach into water systems causing water eutrophication, a major environmental problem caused by an excess release of nutrients. Controlling the release of P in response to the plant demand could reduce fertilizer’s losses and also reduce environmental pollution. This study establishes a concept of controlled release fertilizer, in which a hydrogel fertilizer film is fabricated by incorporating starch, polyvinyl alcohol and ammonium dihydrogen phosphate fertilizer which tend to immobilize the release of phosphate ions and accelerate responsively their release rate in the presence of water. The experiment aims to study the effect of incorporating Starch, and Polyvinyl alcohol (PVA) to Ammonium Dihydrogen Phosphate fertilizer by varying the composition of PVA-Starch-Ammonium Dihydrogen Phosphate and preparing the films through solution casting method. FTIR is being used to investigate the effect of Starch, PVA, and Ammonium Dihydrogen Phosphate composition on the intermolecular bonding of the fabricated film. A total of 10 samples with different material composition is prepared and the intermolecular bonding between this composition is being compared with that of pure starch, pure PVA and pure Ammonium dihydrogen phosphate fertilizer. The FTIR peak will reveal evidence of hydrogen bonding between phosphate molecules and the functional group of polymer molecules as well as showed all the characteristics band of Starch, PVA and Ammonium Dihydrogen Phosphate. The varying formulation of film corresponded to varying intensity of peak and also stretching vibrations.