• Goralczyk, Andreas
• Rapp, Bastian
• Zhu, Pang
• Mayoussi, Fadoua
• Karimi, Kiana
• Nekoonam, Niloofar
• Helmer, Dorothea
• Usama, Ali

Abstract

<jats:p>Superrepellent surfaces, such as micro/nanostructured surfaces, are of key importance in both academia and industry for emerging applications in areas such as self-cleaning, drag reduction, and oil repellence. Engineering these surfaces is achieved through the combination of the required surface topography, such as porosity, with low-surface-energy materials. The surface topography is crucial for achieving high liquid repellence and low roll-off angles. In general, the combination of micro- and nanostructures is most promising in achieving high repellence. In this work, we report the enhancement of wetting properties of porous polymers by replication from wrinkled Parylene F (PF)-coated polydimethylsiloxane (PDMS). Fluorinated polymer foam “Fluoropor” serves as the low-surface-energy polymer. The wrinkled molds are achieved via the deposition of a thin PF layer onto the soft PDMS substrates. Through consecutive supercritical drying, superrepellent surfaces with a high surface porosity and a high water contact angle (CA) of &gt;165° are achieved. The replicated surfaces show low roll-off angles (ROA) &lt;10° for water and &lt;21° for ethylene glycol. Moreover, the introduction of the micro-wrinkles to Fluoropor not only enhances its liquid repellence for water and ethylene glycol but also for liquids with low surface tension, such as n-hexadecane.</jats:p>

Topics

• Deposition
• porous
• impedance spectroscopy
• surface
• polymer
• porosity
• drying