Work

Supercooled condensation droplets sliding on frost: Origin and anti-frosting effect observed on Cotinus coggygria leaf

Year: 2024

Type: article

Abstract: Summary Fascinated by the purple color, water-repellent, and self-cleaning properties of Cotinus coggygria Scop. leaves, we studied their morphology, wetting, and condensation frosting. Wax nanotubules confer high contact angles, enabling coalescence-induced condensation droplet (out-of-plane) jumping, which, as known, contributes to slowing down frost. Another type of movement—this time in-plane—becomes predominant in reducing the frosting velocity ( vfrost ) within a sub-cooling temperature range. Specifically, supercooled droplets slide toward the frost bridges upon contact, moving in the opposite direction to frost propagation. Between −11 and −2°C, Sliding on Frost (SoF) shifts from being rare to very frequent, reducing vfrost/vbridge from approximately 4 to 1, respectively. Using high-speed microscopy, we observed that the advancing contact angle of supercooled water on ice decreases with temperature. We describe the primary role of this behavior in SoF with a model that accounts for the forces involved and explains the observed transition.

Source: iScience

DOI: 10.1016/j.isci.2024.111056

Authors: Nicolò Giuseppe Di Novo, Alvise Bagolini, Nicola Maria Pugno

Institutions: University of Trento, Fondazione Bruno Kessler, Queen Mary University of London

Language: English

Topic: Surface Modification and Superhydrophobicity

Subfield: Surfaces, Coatings and Films

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,150

Funders: European Commission, Università degli Studi di Trento, H2020 Future and Emerging Technologies