Non-Fluorinated Omniphobic Paper with Ultralow Contact Angle Hysteresis

Existing methods for fabricating oil-repellent paper rely on highly fluorinated and therefore toxic chemicals. Non-fluorinated omniphobic paper with low contact angle hysteresis (CAH) has not been demonstrated. We report a facile method to prepare omniphobic paper through the vapor-phase deposition of chlorosilane molecules to create "liquid-like" polymer brushes on commercially available release liners. Compared to polymer brushes grafted from solution, this solvent-free method avoided physical deformation of the paper, such as curling or wrinkling. The obtained paper displayed low CAH (<6°) and roll-off angles for liquids exhibiting a broad range of surface tension, from 72.8 to 22.4 mN m^-1. A hexadecane droplet (15 μL, 27.5 mN m^-1) slid off the paper at a tilt angle less than 4°. The effects of surface roughness, composition, and the presence of particle additives on the wetting properties were investigated. The utility of the omniphobic paper was demonstrated in microfluidic, oil funnel, microtiter plate, and food packaging container applications.