BACKGROUNDSurfactants regulate the interaction between pesticide droplets and the surfaces of plants on which they are sprayed. The influence of the key structural functional groups of surfactants on the interaction between pesticide droplets and hydrophobic pear leaves has not been explored. The behavior of Imidacloprid (Imid) droplets regulated by cationic quaternary ammonium surfactants with different structures on hydrophobic pear leaves and their bouncing dynamics were studied.RESULTSThe properties of pesticide droplets regulated by rosin‐based bicationic quaternary ammonium salt and ethylene (dodecyl polyoxyethylene/tetradecyl polyoxyethylene) chloride/ammonium bromide were well matched with those of pear leaves with a waxy layer. This structure was closely related to the double‐chain structure corresponding to that of double N‐head groups in quaternary ammonium surfactants. Quaternary ammonium surfactants regulate the wetting of droplets by forming semi‐micellar structures near the three‐phase contact line, which drives the droplets to wet and spread on the leaf. The quaternary ammonium surfactant containing the double N‐head structure enabled strong wetting and adhesion of pesticide droplets on the hydrophobic surface. The key structural functional groups of different quaternary ammonium surfactants directionally modified the impact kinetics of Imid droplets on the leaf surfaces and their changing trend.CONCLUSIONThe double N‐head structure played a key role in the molecular structure of quaternary ammonium surfactants, and the hyperbranched ethylene oxide (EO) chain played a small role in the molecular structure. These results clearly indicate how the structure of key functional groups of quaternary ammonium surfactants regulated the interface adhesion of pesticide droplets on the leaf surfaces and explain the microscopic mechanism of their interaction. © 2024 Society of Chemical Industry.

中文翻译：

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季铵盐表面活性剂分子自组装调控农药液滴冲击和疏水表面润湿的机理和策略


背景活性剂调节农药液滴与喷洒它们的植物表面之间的相互作用。表面活性剂的关键结构官能团对农药液滴与疏水梨叶相互作用的影响尚未得到探讨。研究了不同结构的阳离子季铵表面活性剂调控的吡虫啉 （Imid） 液滴在疏水性梨叶上的行为及其弹跳动力学。结果松香基二元季铵盐和乙烯（十二烷基聚氧乙烯/四癸基聚氧乙烯）氯化铵/溴化铵调控的农药液滴的特性与具有蜡质层的梨叶的特性非常匹配。该结构与季铵盐表面活性剂中双 N 头基团的双链结构密切相关。季铵盐表面活性剂通过在三相接触线附近形成半胶束结构来调节液滴的润湿，从而驱动液滴润湿并在叶片上扩散。含有双 N 头结构的季铵盐表面活性剂使农药液滴在疏水表面上具有很强的润湿和粘附作用。不同季铵盐表面活性剂的关键结构官能团定向改变了 Imid 液滴对叶片表面的冲击动力学及其变化趋势。结论双 N 头结构在季铵盐表面活性剂的分子结构中起关键作用，超支化环氧乙烷 （EO） 链在分子结构中起小作用。 这些结果清楚地表明了季铵盐表面活性剂关键官能团的结构如何调节农药液滴在叶片表面的界面粘附，并解释了它们相互作用的微观机制。© 2024 化工学会.