Synthesis of biopolymeric particles loaded with phosphorus and potassium: characterisation and release tests

The authors synthesised nanoparticles (NPs) loaded with P and K from KH2PO4 using gelatin type-A and type-B, and sodium alginate as carriers. Using type-A and type-B gelatin, quasi-spherical particles were obtained, with average sizes of 682 and 856 nm, respectively; with sodium alginate, the resulting NPs exhibited spherical shapes and 600 nm particle average size. The authors found an interaction between KH2PO4 and alginate via the hydrogen bonds existent among the carboxylic groups of the carbohydrate and the OH-groups of the H2PO4-; interactions among gelatin types with the OH-groups and the H2PO4-ion were also observed. Adding trypsin to the distilled water solutions of the NPs coated with type-A gelatin increased the concentration of P in the solution by threefold, while increasing that of K increased by 2.6-fold. Conversely, adding α-amylase to the water solutions with sodium alginate increased the P and K concentrations in the solution by nearly 1.3- and 1.1-fold, respectively. Thus, sodium alginate resulted in NPs with smaller sizes and better spherical formations, though with a high polydispersity index and lower release rate of P and K. This low release rate represents an advantage since plants demand nutrients for long periods, and conventional fertilisers display low use efficiency.
Source: IET Nanobiotechnology - Category: Nanotechnology Source Type: research