Fabrication of ionic liquid self-assemblies based on dicamba with improved herbicidal activity and reduced...

Area of Science:

• Agricultural Chemistry
• Materials Science
• Environmental Science

Background:

• Off-target pesticide loss via volatilization and leaching reduces efficacy and poses environmental risks.
• Self-assembly of pesticides, particularly into herbicidal ionic liquids (HILs), is a promising strategy to enhance bioactivity and environmental compatibility.
• Improving herbicide physicochemical properties is key to minimizing off-target movement and increasing safety.

Purpose of the Study:

• To develop herbicidal ionic liquid nanoparticles (HIL NPs) for reduced pesticide off-target loss.
• To investigate the self-assembly of dicamba-based HILs into nanoparticles.
• To evaluate the physicochemical properties and environmental safety of the synthesized HIL NPs.

Main Methods:

• HILs were synthesized by pairing dicamba with quaternary ammonium salts of varying alkyl chain lengths and aromatic groups.
• HIL NPs were formed through electrostatic interaction and hydrophobic effects.
• Physicochemical properties (particle size, zeta potential, volatilization rate, surface tension, contact angle, leaching potential, soil adsorption) were analyzed.
• Efficacy against Amaranthus retroflexus was compared between HIL NPs and dicamba sodium salt.

Main Results:

• HIL NPs with particle sizes ranging from 6-55 nm were successfully prepared.
• The HIL NPs exhibited significantly improved properties: high zeta potential (+20.3 to +27.8 mV), low volatilization (2.4-3.9%), low surface tension (22.83-33.07 mN m⁻¹), decreased contact angle (32.25-41.55°), reduced leaching potential (76.2-86.5%), and high soil adsorption (12.1-23.8%).
• HIL3 NPs showed superior weed control efficacy against Amaranthus retroflexus compared to dicamba sodium salt.

Conclusions:

• Dicamba-based HIL NPs offer enhanced physicochemical properties, reducing environmental risks associated with volatilization and leaching.
• The facile and green self-assembly approach provides a viable method for developing safer and more effective pesticide formulations.
• This technology holds significant potential for advancing sustainable agriculture through improved pesticide delivery and reduced environmental impact.