Durable nonfluorinated stochastically hierarchical superhydrophobic interface for intense long-term phase change cooling

Berce, Jure (author), Hadžić, Armin (author), Zupančič, Matevž (author), Može, Matic (author), Golobič, Iztok (author)

Advanced superhydrophobic interfaces, where strong water repellency is imparted on top of micro- and nanoengineered surface features, have demonstrated enhanced boiling heat transfer with the potential to drastically improve the efficiency of thermal management. However, their practical deployment is impeded by degradation of favorable characteristics, resulting from thermo-chemo-physical strain during prolonged bubble or vapor patch formation. Building on extensive past work where the leading degradation mechanisms of long-term pool boiling were analyzed, a novel six-step surface engineering procedure is developed in this work to effectively mitigate boiling-induced degradation on superhydrophobic copper samples. Laser microengineering is coupled with a UV-ozone-activated gold nanolayer, upon which a fluorine-free monolayer is deposited to induce superhydrophobicity. The developed stochastically hierarchical interface repeatably demonstrates enhanced boiling heat transfer at low wall superheats with HTC improvements up to 460%, while its micromorphology and wetting remain intact even after several hundred hours of vigorous pool boiling. With practical implementation in mind, the interface is stress-tested at elevated temperatures and repeated CHF onsets, exhibiting unparalleled durability of wetting behavior and heat transfer stability. Through this work, it is sought to advance the practical application of superhydrophobicity, moving closer to realizing its full potential in advanced phase change cooling solutions.

• Language: English
• Keywords: durability, heat transfer, hierarchical structures, laser texturing, long-termboiling, phase change cooling, superhydrophobicity
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 12 str.
• Numbering: Vol. 6, issue 11, art. 2500326
• PID: 20.500.12556/RUL-171233
• UDC: 536.24:544.722.132
• ISSN on article: 2688-4062
• DOI: 10.1002/sstr.202500326
• COBISS.SI-ID: 246074627
• Publication date in RUL: 20.08.2025

Record is a part of a journal

• Title: Small structures
• ISSN: 2688-4062
• COBISS.SI-ID: 176172547

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: odpornost, prenos toplote, hierarhične strukture, lasersko teksturiranje, dolgotrajno vrenje, hlajenje s fazno spremembo, superhidrofobnost