Green Synthesis of Copper Chitosan Nanoparticles for Controlled Release of Pendimethalin

Abstract

Aim: In a bid to reduce the environmental impact from the use of herbicides, chitosan was used for the synthesis of copper nanoparticles and the controlled release formulations (CRFs) of pendimethalin copper-chitosan nanoparticles (Pend-CuCtsNPs). Methodology: The synthesized nanoparticles were characterized using UV-visible spectroscopy, Fourier Transform Infra-Red (FT-IR), Powder X-ray diffraction (PXRD), Transmission electron microscopy (TEM) and Energy-dispersive x-ray (EDX). Average crystalline size of the nanoparticles was estimated from the Debye- Scherrer’s equation. Results: The yield of the synthesized CuCtsNPs increased linearly with the weight of the starting material with percentage yield of 93.8% for the 0.8% chitosan matrix. Encapsulation efficiency of the nano-formulation fell within 57.5 and 92.7%. The aqueous release studies of Pend-CuCtsNPs, monitored for 96 hours in a batch release mode were carried out in three different pH media and percentage herbicide released for all composites showed that the release in pH 5.5 (acidic) medium was higher and the lowest release was recorded for pH 7.0 (neutral) medium. There was a statistically significant difference between pH groups and time as determined by UNIANOVA          (p < .005). Conclusion: Findings from this study however shows that there is a controlled release of pendimethalin using nano-formulation over the conventional herbicide application.