Solvent-free pesticide encapsulation and delivery using water-soluble bioderived polymers

Overview

This technology offers a sustainable alternative to conventional pesticide encapsulation by eliminating the need for large volumes of organic solvents. It uses oppositely charged, water-soluble polymers that interact electrostatically in water and assemble into polymer-rich phases. When a salt-loaded aqueous solution containing polymers and pesticide cargo is sprayed into salt-free water, the salt screens the electrostatic interactions and triggers precipitation, forming a polymeric shell around the active ingredient. The approach supports both hydrophobic and hydrophilic pesticides and enables tunable adhesion to leaf surfaces, sustained release, and controlled degradation.

Technical specifications

Core mechanism:

• Salt-inversion phase separation of polyelectrolyte complexes in aqueous media
• Spray-triggered precipitation of polymer-pesticide mixtures into salt-free water
• Patented stabilization of polyelectrolyte phases using commercially available polymers

Polymer systems under investigation:

• Synthetic polyelectrolytes including polyacrylic acid, polyallylamine hydrochloride, and polystyrene sulfonate
• Bioderived degradable polymers including chitosan, hyaluronic acid, and polylipoic acid
• Polymer architectures incorporating imine moieties designed to degrade on exposure to CO2 for triggered cargo release

Process advantages:

• Organic solvent-free manufacturing reduces environmental impact and cost
• Polymer diversity enables customization for different leaf surfaces, cargo types, and release profiles
• Variable injection rates and concentrations allow control over shell formation and encapsulation efficiency

Technology readiness level

The underlying principles of polyelectrolyte complexation and salt-triggered phase separation are well established in both theory and experiment, with active research in encapsulation of active cargo. The research group has patented a stabilization mechanism for these aqueous phases using inexpensive, commercially available polyelectrolytes. Future validation will focus on controlling precipitation during spraying, screening polymer candidates for encapsulation efficiency across cargo types, and characterizing CO2-triggered degradation and release behavior. The technology is at an early-to-mid stage of development, moving from laboratory validation toward broader application testing.