Development of bioinspired and sustainable fatty acid-based coatings for multifunctional protection of agricultural crops

The global imperative for sustainable agriculture demands innovative, non-toxic solutions to boost crop resilience against climatic extremes. The increasing frequency of high temperatures and unpredictable moisture events elevates the risk of widespread crop failure, particularly for plants lacking natural waxy barriers. To address this, we developed a synthetic superhydrophobic (SH) coating from naturally abundant stearic acid (SA), creating an eco-friendly, biomimetic, air-trapping surface. Employing a simple, continuous spraying method, the process enabled the rapid, controlled self-assembly of SA, reliably producing highly effective SH coatings (CA ). X-ray Diffraction (XRD) confirmed the stable C-polymorph of SA, while Scanning Electron Microscopy (SEM) verified the required hierarchical microstructure that enables the extreme water-repellency of the Cassie-Baxter regime. This SA-based SH coating demonstrated exceptional durability, maintaining its properties after severe exposure to high heat ( ), freezing ( ) and UV-C radiation. Functionally, the coating provides multifunctional physical protection: first, the SH surface significantly inhibits water condensation on leaves, mitigating the effects of prolonged surface moisture; it provides passive thermal regulation. Coated plants exhibited a significant cooling effect under direct sunlight (up to 3 less), spectroscopically attributed to the coating`s high Near-Infrared (NIR) reflectivity (700–1400nm). Crucially, the coating achieves up to 95% visible light transmittance (%T) for maximum Photosynthetically Active Radiation (PAR) absorption. Furthermore, controlling coating thickness allows for tuning transmittance, enabling a controlled "shadow effect" similar to a greenhouse net. We are also developing an innovative solvent-free formulation that surpassed this performance (up to 7.5 less than uncoated plant) and maintain its SH characteristic. This innovative formulation is more sustainable and environmentally friendly.