Uniform Spread of High-Speed Drops on Superhydrophobic Surface by Live-Oligomeric Surfactant Jamming

Adv Mater. 2019 Oct;31(41):e1904475. doi: 10.1002/adma.201904475. Epub 2019 Aug 29.

Abstract

Inkjet printing of water-based inks on superhydrophobic surfaces is important in high-resolution bioarray detection, chemical analysis, and high-performance electronic circuits and devices. Obtaining uniform spreading of a drop on a superhydrophobic surface is still a challenge. Uniform round drop spreading and high-resolution inkjet printing patterns are demonstrated on superhydrophobic surfaces without splash or rebound after high-speed impacting by introducing live-oligomeric surfactant adhesion. During impact, the live-oligomeric surfactant molecules aggregate into dynamic, wormlike micelle networks, which jam at the solid-liquid interface by entangling with the surface micro/nanostructures to pin the contact line and jam at the spreading periphery to keep the uniform spreading lamellar shape. This efficient uniform spreading of high-speed impact drops opens a promising avenue to control drop impact dynamics and achieve high-resolution printing.

Keywords: inkjet printing; superhydrophobicity; surfactants.