Hydrodynamic cavitation: A bottom-up approach to liquid aeration

Research output: Contribution to journalArticle

Authors

  • Janhavi S. Raut
  • Simeon D. Stoyanov
  • Charu Duggal
  • Luben N. Arnaudov
  • Vijay M. Naik

Colleges, School and Institutes

External organisations

  • Unilever
  • Unilever Research and Development
  • Wageningen University and Research Centre
  • Department of Mechanical Engineering
  • Indian Institute of Technology, Bombay

Abstract

We report the use of hydrodynamic cavitation as a novel, bottom-up method for continuous creation of foams comprising of air micro-bubbles in aqueous systems containing surface active ingredients, like proteins or particles. The hydrodynamic cavitation was created using a converging-diverging nozzle. The air bubble size obtained using this technique was found to be significantly smaller than that achieved using conventional mechanical entrapment of air via shearing or shaking routes, which are in essence top-down approaches. In addition, the technique provided the possibility of forming non-spherical bubbles due to the high elongational stresses experienced by the bubbles as they flow through the nozzle throat. We show that surface active agents with a high surface elasticity modulus can be used to stabilize the nascent air bubbles and keep their elongated shapes for prolonged periods of time. This combination of the cavitation process with appropriate surface active agents offers an opportunity for creating bubbles smaller than 10 microns, which can provide unique benefits in various applications.

Details

Original languageEnglish
Pages (from-to)4562-4566
Number of pages5
JournalSoft Matter
Volume8
Issue number17
Publication statusPublished - 7 May 2012