Rapid formation of transparent superhydrophobic film on glasses by He/CH₄/C₄F₈ plasma deposition at atmospheric pressure

A transparent superhydrophobic surface on glass is prepared by a rapid single-step method using a He, CH₄, C₄F₈ mixture plasma at atmospheric pressure. Water droplet contact angles and surface properties are investigated to analyze both chemical and physical characteristics of the plasma treated surfaces. As the C₄F₈ gas flow rate is increased in the He/CH₄ plasma, both advancing, and receding water contact angles are increased, while UV-visible transmittance is degraded. By optimizing the gas mixture ratio, we find rapid deposition conditions for superhydrophobic formation without losing the visible to near-infrared transparency of the glass. The chemical and physical mechanism responsible for hydrophobicity is also discussed through the investigation of chemical composition and surface morphology.