Controlling high‐speed droplet splashing and superspreading behavior on anisotropic superhydrophobic leaf surfaces by ecofriendly Pseudogemini surfactants

Abstract

Background: Efficient deposition of high-speed droplets on superhydrophobic leaf surfaces remains an important challenge. For anisotropic wired superhydrophobic leaf surfaces, the splashing phenomenon is especially serious because it leads to the low effective utilization of pesticides by biological targets. The lost pesticides cause serious ecological environment pollution, therefore there is an urgent need to develop a green and sustainable cost-effective strategy to achieve efficient deposition of high-speed droplets on anisotropic superhydrophobic leaf surfaces at low dosage.Results: One type of green pseudogemini surfactant 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 complete inhibition of the bouncing of droplets, but also promote rapid spreading on superhydrophobic leaf surfaces at 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 the surface tension gradient. Moreover, the surfactant shows an excellent synergistic effect with herbicides to control weeds by inhibiting droplet splashing. Conclusion:This work provides a simpler, more 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.

Mechanism Study on the Alcoholysis and Polymerization Degree of Poly(vinyl alcohol) to Regulate Droplet Impact Behavior on Hydrophobic Surfaces

“…Droplet impact behavior has important research significance in inkjet printing, , aerospace, medicine, − agriculture, − and other fields. Especially, in the process of pesticide spraying, plant leaves exhibit hydrophobicity generated by multistage micro and nano structures and a variety of chemical components, resulting in the pesticide solution easily bouncing, tumbling, − gathering, and being lost when it hits the surface of plant leaves. According to the statistics of the Ministry of Agriculture and Rural Affairs, as of 2022, the pesticide utilization rate of the three major food crops of rice, corn, and wheat in China is only 41%, so a large number of pesticides enter the environment in the process of use, affecting crop production and the surrounding ecological environment, and even endangering the life and health of humans and animals. − …”