Eco-friendly 2,4-D dimethylamine herbicide delivery system using synthesized nano-matrix

This study used chitosan as a capping agent and L-ascorbic acid as reducing agent to prepare copper nanoparticles encapsulated with 2,4-D dimethylamine herbicide via a green chemical reduction method to improve its herbicidal activity and reduce the negative environmental impacts associated with its application. Characterization of the synthesized CuCtsNPs and 2,4-D-CuCtsNPs was carried out using the following techniques; transmission electron microscopy (TEM), fourier transform- infra-red (FT-IR), scanning electron microscopy (SEM), energy-dispersive x-ray (EDX), powder x-ray diffraction (PXRD), differential scanning calorimeter (DSC), thermogravimetric  and differential thermal analysis (TGA/DTA). The maximum absorption peak of CuCtsNPs was observed around 560 nm while that of 2,4-D-CuCtsNPs at 558 nm. The yield of CuCtsNPs was at the range of 40-92% and encapsulation efficiency of the 2,4-D-CuCtsNPs formulationwas 93%. Debye- Scherer’s equation was used to calculate the average crystalline size of the synthesized CuCtsNPs and 2,4-D-CuCtsNPs. The values were 38.78 nm (CuCtsNPs) and 54.93 nm (2,4-D-CuCtsNPs) respectively. The SEM images revealed the particle size of 21-56 nm for CuCtsNPs and 25-69 nm for 2,4-D-CuCtsNPs. The results obtained from the DSC and TGA curves of CuCtsNPs and 2,4-D-CuCtsNPs showed that the formulations exist in crystalline state and were thermally stable up to 401.73 °C. Aqueous release studies for the formulation were carried out in three different pH media and two agricultural soils. Leaching profile of the loaded CuCtsNPs through the soil layer (UAM and CAPS) demonstrated that the UAM soil had higher value for 2,4-D (58.67%) than in CAPS soil 40.78%. This study formulated an environmentally friendly herbicide delivery nano-matrix (CuCtsNPs) for the successful slow release of 2,4-D Dimethylamine herbicide in aqueous medium and agricultural soils.