Multi-stimuli-responsive metal-polyphenol nanocapsules: From self-assembly mechanism to morphology-controlled foliar interfacial adhesion.

Abstract

Achieving controlled release and dynamic interfacial adhesion at complex biological surfaces using soft colloidal carriers remains a fundamental challenge in colloid and interface science. Herein, we fabricate STPF nanocapsules via spontaneous self-assembly driven by hydrogen bonding of sustainable precursors and metal-polyphenol coordination crosslinking. The assembly mechanism-governed by synergistic π-π stacking, hydrogen bonding, and metal-phenolic coordination-is rigorously verified by FTIR, 1H NMR, XPS, and molecular dynamics simulations. Through a facile sol-gel crosslinking strategy with BHT via hydrogen bonding, the STPF network enables universal encapsulation of multiple pesticides (phoxim, lambda-cyhalothrin, abamectin) with scalable manufacturing potential. The pesticide-loaded nanocapsules exhibit multi-stimuli-responsive release behaviors triggered by ROS, Fe3+, pH, and laccase, accompanied by particle swelling and structural softening-a dynamic morphological evolution that actively modulates the nanocapsule-foliar interfacial interaction. Compared with conventional suspension concentrates, STPF nanocapsules achieve significantly enhanced rainfastness and retention on cowpea stems, with improvements in abamectin photostability (54.71%), rainfastness (49.19%), and stem retention (9.24%). Critically, the structural softening during cargo release further fortifies foliar retention over time, elevating 24 h control efficacy against Tetranychus urticae by up to 38.24%. This work establishes a mechanistic linkage between stimuli-driven morphology evolution and programmable interfacial adhesion, offering fundamental insights into the design of smart soft colloidal systems with environment-adaptive interfacial behavior.

Abstract as supplied by the indexing source. © the authors / publisher.