Hydrophobic modification of cellulose nanofibers/bionic flower-like ZnO synergistically stabilized Pickering emulsion to enhance pesticide deposition

Int J Biol Macromol. 2024 Dec 18:138967. doi: 10.1016/j.ijbiomac.2024.138967. Online ahead of print.

Abstract

Environmental issues arising from the low pesticide utilization rate make the development of environmentally friendly and low-cost pesticide carrier systems an urgent problem to be solved. Pickering emulsion systems have shown broad application prospects in pesticide delivery. In this study, dodecenyl succinic anhydride (DDSA) was used to hydrophobically modify cellulose nanofiber (D-CNF), and biomimetic flower-like zinc oxide (ZnO) particles were prepared by precipitation method at room temperature. Then the two functioned synergistically as stabilizers for the Pickering emulsion, which significantly diminished the reliance on conventional surfactants. Turpentine, an essential oil, was used as a solvent for the broad-spectrum herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and as a part of the oil phase in an emulsion, replacing traditional toxic solvents for pesticide dissolution in the construction of a Pickering emulsion system. ZnO/D-CNF formed a dense layer at the oil-water interface to prevent droplet aggregation. After the Pickering emulsion contacted the leaves, ZnO could be embedded and adhere to leaves due to its morphology, which effectively reduced the splash of the droplets. No matter what the inclination angle was, the droplets could adhere and diffuse on the leaves. This study presents a new idea for creating a simple, eco-friendly, and practical pesticide carrier system.

Keywords: Pesticide carrier; Pickering emulsion; Synergistic effect.