Aqueous formulation improves pesticide deposition

Researchers at the University of Waterloo have developed a water-based formulation using nanotechnology to improve pesticide deposition on leaves. The solution increased droplet adhesion, reduced splashing, and minimized losses due to runoff and drift.

The formulation uses cellulose nanocrystals modified with tannic acid and cupric chloride. The system combines these nanocrystals with methylcellulose and the surfactant Aerosol OT. The resulting structure stabilizes the droplets upon impact with hydrophobic surfaces.

In tests described by the scientists, the formulation with 0,1% Aerosol OT, 0,1% modified nanocrystals, and 0,15% methylcellulose achieved 88,92% deposition on superhydrophobic sheets. This performance was 17 times better than that of water.

According to the researchers, the main factor in reducing splashing involves the formation of a network based on modified nanocrystals. This network preserves the integrity of the droplet. The droplet does not fragment or bounce after impact. It flattens on the leaf surface and forms an adherent film.

The technology aims to replace solvent-dependent formulations. "We are spraying water, not solvent," said Michael Tam, professor of chemical engineering at the University of Waterloo. According to him, the approach aligns with sustainable agriculture goals.

The study also evaluated environmental resistance, dispersibility, biocompatibility, antibacterial activity, and insecticidal performance. In initial trials on cabbage plots with an industrial partner in Singapore, the formulation showed better pest control with a lower volume of pesticide compared to conventional delivery systems.

Further information: doi.org/10.1016/j.jcis.2025.139564