Coacervate‐Enhanced Deposition of Sprayed Pesticide on Hydrophobic/Superhydrophobic Abaxial Leaf Surfaces

Abstract

speed droplets on inverted surfaces is important to many fundamental scientific principles and technological applications. For example, in pesticide spraying to target pests and diseases emerging on abaxial side of leaves, the downward rebound and gravity of the droplets make the deposition exceedingly difficult on hydrophobic/superhydrophobic leaf underside, causing serious pesticide waste and environmental pollution. Here, a series of bile salt/cationic surfactant coacervates are developed to attain efficient deposition on the inverted surfaces of diverse hydrophobic/superhydrophobic characteristics. The coacervates have abundant nanoscale hydrophilic/hydrophobic domains and intrinsic network-like microstructures, which endow them with efficient encapsulation of various solutes and strong adhesion to surface micro/nanostructures. Thus, the coacervates with low viscosity achieve high-efficient deposition on superhydrophobic abaxial-side of tomato leaves and inverted artificial surfaces with a water contact angle from 170°to 124°, much better than that of commercial agricultural adjuvants. Intriguingly, the compactness of network-like structures dominantly controls adhesion force and deposition efficiency, and the most crowded one leads to the most efficient deposition. The tunable coacervates can help comprehensively understand the complex dynamic deposition, and provide innovative carriers for depositing sprayed pesticides on abaxial and adaxial sides of leaves, thereby potentially reducing pesticide use and promoting sustainable agriculture.

Ecofriendly Controlled-Release Insecticide Carrier: pH-/Temperature-Responsive Rosin-Derived Hydrogels for Avermectin Delivery against Mythimna separata (Walker)

“…49 The hydrophobicity of hydrogels can improve their utilization by promoting the deposition of hydrophobic insecticides (such as AVM) on the leaf surface. 50 Thermal Analyses. Thermogravimetry−differential thermogravimetry (TG−DTG) analysis was used to study the thermal stability of the hydrogels.…”

Interfacial stabilization of aqueous two-phase systems: a review

“…Due to the low interfacial tension and the ability for rapid transport, these systems have found great utility as cellular mimics, 148–152 bioreactors, 80,134,150,152–160 and carriers. 95,97 Because these systems mimic membraneless organelles, they have been used to study cellular processes outside of a cellular environment, not least of which are enzymatic pathways and cascades, as well as synthetic processes such as nanoparticle catalysis. 152,155–159,161 They have also been used to encapsulate scents for perfumes 81,82 and hold great promise for other encapsulation strategies and applications.…”

“…on the composition and properties of the coacervate and supernatant phases has emerged. 93 The crowded interiors of the coacervates and their ability to sequester charged (bio)macromolecules from their surroundings have promoted their utility as encapsulants and stabilizers in biological, 79,94 industrial, 95–97 environmental, 17,19,83 and cosmetic applications. 81,82…”

Smart and Sustainable Crop Protection: Design and Evaluation of a Novel α-Amylase-Responsive Nanopesticide for Effective Pest Control

“…However, the superhydrophobic nature of crop leaves poses a significant obstacle to the effective deposition and long-term adhesion of nanopesticides, especially in regions experiencing heavy rainfall . To address this issue, researchers have developed dynamic covalent nanogels to encapsulate pesticide, which performed superior affinity to superhydrophobic leaf surfaces . These emerging nanogels prolong the duration of contact between spray droplets and hydrophobic leaf surfaces, leading to more efficient pest control and reduced pesticide application frequency. − However, the creation of nanocarriers through the self-assembly of nanogels requires innovative design, complex monomers, and stringent reaction conditions, , thereby limiting their practical application in the field.…”