Fabricating Tunable Superhydrophobic Surfaces Enabled by Surface‐Initiated Emulsion Polymerization in Water

Abstract Fabricating controllable superhydrophobic surfaces remains challenging in various fields ranging from chemical industries to biomedical engineering. Conventional methods commonly require volatile organic solvents and the assistance of special surface deposition and modification equipment, which are detrimental to environment and limit their applications in micro‐devices. Herein, an equipment‐free method is reported to directly transform fluorinated monomer micro‐droplets into hydrophobic polymer particles on flat substrate surfaces in water, simultaneously depositing hydrophobic coatings with tunable surface structures. The as‐prepared surfaces show superior superhydrophobicity and great stability in extreme conditions (e.g., varying acidity, basicity, and heating conditions), and excellent anti‐fouling property. Meanwhile, surface hydrophobicity can be manipulated by adjusting emulsion droplet number density and reaction time. Hence, superhydrophobic surfaces with tunable hydrophobicity gradients have been successfully fabricated in one pot. This study provides an equipment‐free method to facilely fabricate controllable superhydrophobic surfaces, with great potential in the development of smart superhydrophobic materials in various engineering and industrial applications.