Controlling High-Speed Droplet Splashing and Superspreading Behavior on Anisotropic Superhydrophobic Leaf Surfaces by Ecofriendly Pseudogemini Surfactants.

Abstract

Efficient deposition of high-speed droplets on superhydrophobic leaf surfaces remains an important challenge. Especially for the anisotropic wired superhydrophobic leaf surface, the splashing phenomenon is more serious, which leads to the low effective utilization of pesticides by biological targets. The lost pesticides have caused serious ecological environment pollution. Therefore, it is urgent to develop a green and sustainable strategy in a cost-effective to achieve efficient deposition of high-speed droplets on anisotropic superhydrophobic leaf surfaces at low dosage. A kind of green pseudogemini surfactants is constructed based on fatty acids and hexamethylenediamine by electrostatic interaction to control the splashing and spreading of high-speed droplets on superhydrophobic surfaces. The formed surfactant can not only achieve completely inhibition of the bouncing of droplets, but also promote the rapid spreading on superhydrophobic leaf surfaces at a very low usage. The efficient deposition and superspreading phenomenon are attributed to the rapid migration and adsorption of the surfactant from the dynamic spherical micelles at the newly formed solid-liquid interface, the network-like aggregated spherical micelles, and the Marangoni effect caused by surface tension gradient. Moreover, the surfactant shows excellent synergistic effect with herbicides to control weeds by inhibiting droplets splashing. This work provides a more simple, effective and sustainable approach to utilize aggregated spherical micelles rather than conventional vesicles or wormlike micelles to improve the droplet deposition on superhydrophobic leaf surfaces and reduce the impact of surfactants and pesticides on the ecological environment. This article is protected by copyright. All rights reserved.