Iron/NPK agrochemical formulation from superabsorbent nanocomposite based on maize bran and montmorillonite with functions of water uptake and slow-release fertilizer

Abstract

A new type of slow-release multinutrient fertilizer formulation was prepared using a maize bran-g-poly(acrylic acid-co-acrylamide)/montmorillonite superabsorbent nanocomposite. FTIR and ¹H NMR analyses, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to characterize the chemical structure and surface morphology of the prepared materials. The swelling kinetics and reswelling ability of the hydrogels were investigated. In addition, the effect of the solution pH and various saline solutions on the water absorbency of the hydrogels was studied. The equilibrium swelling capacity of a hydrogel sample increased dramatically from 677 g g⁻¹ to 950 g g⁻¹ as 10 wt% MMT was introduced. Furthermore, the incorporation of MMT into the hydrogel network improved its salt resistance property. Besides, the superabsorbent nanocomposite exhibited better pH-sensitive swelling behavior and good reswelling ability. Fertilizer release assessments revealed that the multinutrient-loaded superabsorbent nanocomposite possessed excellent slow-release behavior. Such desirable characteristics make the superabsorbent nanocomposite a very suitable candidate for simultaneously meeting the needs of plants for essential nutrients and water.