The interaction of nonionic surfactant hexaethylene glycol monododecyl ether (C₁₂E₆) with a reconstituted cuticular wheat wax film has been investigated by spectroscopic ellipsometry and neutron reflection (NR) to help understand the role of the leaf wax barrier during pesticide uptake, focusing on the mimicry of the actions adjuvants impose on the physical integrity and transport of the cuticular wax films against surfactant concentration. As the C₁₂E₆ concentration was increased up to the critical micelle concentration (CMC = 0.067 mM), an increasing amount of surfactant mass was deposited onto the wax film. Alongside surface adsorption, C₁₂E₆ was also observed to penetrate the wax film, which is evident from the NR measurements using fully protonated and chain-deuterated surfactants. Furthermore, surfactant action upon the model wax film was found to be physically reversible below the CMC, as water rinsing could readily remove the adsorbed surfactant, leaving the wax film in its original state. Above the CMC, the detergency action of the surfactant became dominant, and a significant proportion of the wax film was removed, causing structural damage. The results thus reveal that both water and C₁₂E₆ could easily penetrate the wax film throughout the concentration range measured, indicating a clear pathway for the transport of active ingredients while the removal of the wax components above the CMC must have enhanced the transport process. As the partial removal of the wax film could also expose the underlying cutaneous substrate to the environment and undermine the plant’s health, this study has a broad implication to the roles of surfactants in crop care.

中文翻译：

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与非离子表面活性剂C ₁₂ E ₆相互作用时重构的表皮蜡膜的结构特征

非离子表面活性剂六甘醇单_十二烷基醚（C ₁₂ E ₆）与重构的表皮小麦蜡膜之间的相互作用已通过椭圆偏振光谱和中子反射（NR）进行了研究，以帮助理解叶蜡屏障在农药吸收过程中的作用，重点是佐剂作用的模仿模仿了表皮蜡膜的物理完整性和运输对表面活性剂浓度的影响。随着C ₁₂ E ₆浓度增加到临界胶束浓度（CMC = 0.067 mM），越来越多的表面活性剂沉积在蜡膜上。沿表面吸附，C ₁₂ E ₆还观察到了穿透蜡膜的现象，这是使用完全质子化和链氘化的表面活性剂进行的NR测量所证明的。此外，发现在CMC以下，表面活性剂对模型蜡膜的作用在物理上是可逆的，因为水冲洗可以轻易除去吸附的表面活性剂，使蜡膜保持其原始状态。在CMC上方，表面活性剂的去污力起主导作用，大部分蜡膜被去除，造成结构破坏。结果表明水和C ₁₂ E ₆在整个测量的浓度范围内都可能轻易渗透蜡膜，这说明了有效成分运输的清晰途径，而去除CMC上方的蜡组分必须增强了运输过程。由于部分去除蜡膜还会使下面的皮肤基质暴露于环境并损害植物的健康，因此这项研究对表面活性剂在农作物护理中的作用具有广泛的意义。