Synthesis and characterization of a novel controlled release nitrogen-phosphorus fertilizer hybrid nanocomposite based on banana peel cellulose and layered double hydroxides nanosheets

In the present study, a novel environment-friendly hybrid nanocomposite of Banana Peel Cellulose-g-poly(acrylic acid)/PVA (BPC-g-PAA/PVA) hydrogel and Layered double hydroxides (LDH) nanosheets was developed using in situ graft polymerization for slow release of NP (nitrogen, phosphorous) fertilizers and water retention. The hybrid nanocomposite hydrogel containing NP fertilizers was characterized using FTIR, and SEM. The effects of pH changes and different saline solutions on the swelling behavior, fertilizer release and water retention properties of the nanocomposite were investigated. The nanocomposite hydrogel showed a pH dependent swelling, as in the pH range of 7–10, the hydrogel had higher water absorbency. However, pH had opposite effects on the release of fertilizers. Phosphorus release had an increasing trend from pH 2 to 7 and it reached its maximum value at normal pH while nitrogen had a higher release rate at acidic pH and by increasing pH from 2 to 7, the release of nitrogen decreased gradually. Water absorption and fertilizer release of hydrogel was influenced by different cations in the order of Ca2+