Thermally induced nanobubble filaments and cylindrical shock wave formation in colloidal suspension

Orthaber, Uroš (author), Petkovšek, Rok (author)

An interesting phenomenon involving generation of nanobubble filaments in an aqueous colloidal suspension of gold nanoparticles (GNP) is being reported on and discussed in the present paper. The heat for thermally induced nanobubbles is being provided to GNPs by a laser pulse. If specific conditions, such as sufficient laser beam fluence, adequate GNP size and concentration are met self-focusing occurs, which consequently leads to a formation of one or more nanobubble filaments along the beam propagation direction. The nanobubble filaments are made observable by sending a rarefaction wave through the region, where they occur. Depending on the beam fluence, one or more nanobubble filaments are observed and depending on the beam and GNP parameters, the nanobubble filaments may be accompanied by a plasma filament, if thresholds for self-focusing and ionization are exceeded at the same time. In this case a cylindrical shock wave originating from the filament is observed. The present study investigates the influence of GNP size and beam fluence on nanobubble filament formation. It implements a recently developed technique for nanobubble visualization using a rarefaction wave and a multiple illumination pulse technique for shock wave detection.

• Language: English
• Keywords: nanobubble, filament, cylindrical shock wave, Filamentation, Gold nanoparticles
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 7 str.
• Numbering: Vol. 171, art. 111623
• PID: 20.500.12556/RUL-175457
• UDC: 544.2
• ISSN on article: 1879-2286
• DOI: 10.1016/j.expthermflusci.2025.111623
• COBISS.SI-ID: 254915075
• Publication date in RUL: 28.10.2025

Record is a part of a journal

• Title: Experimental thermal and fluid science
• Shortened title: Exp. therm. fluid sci.
• Publisher: Elsevier
• ISSN: 1879-2286
• COBISS.SI-ID: 23399685

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: nanomehurček, filament, cilindrični udarni val

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Funding programme: University of Ljubljana, Interdisciplinary project
• Name: Green Urban Communities of the Future

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0270
• Name: Proizvodni sistemi, laserske tehnologije in spajanje materialov