A robust dynamic dewetting coating with omniphobicity, wear resistance, and scratch repairability

Abstract

Dynamic dewetting coatings (DDCs) with robust structure and omniphobicity are difficult to prepare, and problems such as fragility, easy failure, and short service life hinder their practical applications. Herein, a DDC with omniphobicity, wear resistance, and scratch repairability was prepared by introducing polydimethylsiloxane (PDMS) brushes and polytetrafluorowax (PFW) into the cross-linking network of epoxy. The PDMS brushes are introduced to the cross-linking network by the grafted reaction with polyamidoamine containing 128 NH2 end groups, and then the solidification of the NH2 groups and the epoxy groups. As a result, the prepared coating exhibited excellent omniphobicity to various liquids with different surface energies and viscosities such as water, hexadecane, and sunflower seed oil. Particularly, the contact angle of ethanol (10 μL) on the coating was 13.5 ± 1.0°, and its sliding angle was as low as 6.4 ± 0.7°. Relying on the effect of “liquid lubricant” PDMS brushes and “solid lubricant” PFW, the DDC exhibited excellent tribological properties with friction-reducing and wear resistance. Moreover, the PFW in the coating could experience a solid-to-liquid transition at a specific temperature and flow to the damaged region for repairing effect. Scratches made with a friction tribometer, a knife, or sandpaper on the DDC can be easily repaired by heating, and the repaired coating still had outstanding omniphobicity. Long-term dynamic dewetting stability, excellent stability, and scratch repairability enable the practical application of the prepared DDCs.