Characterization of formulated copper chitosan nanoparticles for the controlled release studies of dicamba dimethylamine herbicide
In this study, a dicamba herbicide was encapsulated onto copper nanoparticles (CuNPs) via a green chemical reduction method in order to improve its herbicidal activity, with the intention of reducing its negative impacts on the environment. The synthesised Dicamba-copper chitosan nanoparticles (Dic-CuCtsNPs) was characterised using UV-visible spectroscopy, scanning electron microscopy (SEM), Fourier transform- infrared (FT-IR), powder x-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermo gravimetric analysis/differential thermal analysis (TGA/DTA) and energy-dispersive x-ray spectroscopy (EDX). The maximum absorption peak of the Dic-CuCtsNPs was observed at 556 nm. The encapsulation efficiency of the Dic-CuCtsNPs formulation was 86 %. The average crystalline size of the nanoparticles, from its PXRD pattern, estimated using the Debye- Scherrer’s equation was 45.94 nm. The SEM image obtained indicated particle size distribution of 16 – 64 nm. The DSC curve showed that the formulation exists in the crystalline state while the TGA data indicated that the formulation was thermally stable up to 425.75oC. Aqueous release study of Dic- CuCtsNPs was carried out using three different pH media and two agricultural soils. The leaching profile of the formulated nano-herbicide through the University of Agriculture (UAM) and college of advance and professional studies (CAPS) soil layer index showed a high value for the UAM soil being 43.84 % higher than in the CAPS soil value of 26.92 %. Thus, an eco-friendly herbicide delivery system was formulated using CuCtsNPs, for the successful release of Dicamba in aqueous medium and agricultural soils.
Keywords: Controlled release, Dicamba, Encapsulation, Green synthesis, Herbicide, Soil