Entrapment of nano-ZnO into alginate/polyvinyl alcohol beads with different crosslinking ions for fertilizer applications.

Zinc oxide nanoparticles (nano-ZnO) are attractive as fertilizer materials but high concentrations may negatively affect the environment. To reduce their dispersion in the environment we entrapped nano-ZnO in biodegradable polymer beads consisting of alginate and polyvinyl alcohol (PVA). The alginate/PVA/ZnO beads were prepared via ionotropic gelation using two different crosslinking ions (Ca and Zn), and the effect of alginate crosslinking ion and PVA content on bead structure, water absorption, water retention and zinc release was investigated.