The mini-emulsion polymerisation of water-insoluble monomers may be undertaken using ultrasonic radiation (high frequency sounds) to initiate the polymerisation reaction.

Ultrasonic waves cause a microbubble to form and then collapse, with temperatures in the bubble reaching thousands of degrees celcius. These temperatures are able to break water molecules to form radicals that then can commence polymerisation in the same way as a conventional chemical initiator.

Schematic of cavitation

The research that was undertaken in this area continues the work of Melanie Bradley with a view to understanding more of the physical processes that occur during the polymerisation, such as the role of diffusion of monomer across the water phase [1, 2].

Conversion vs time for MMA/BA copolymerisations

The Sonochemistry group at the University of Melbourne is involved in this project, with Boon Teo studying related systems.


  1. Miniemulsion copolymerization of methyl methacrylate and butyl acrylate by ultrasonic initiation. MA Bradley, SW Prescott, HA Schoonbrood, K Landfester and F Grieser. Macromolecules, 38(15), 6346–6351, 2005.
  2. Ultrasound initiated miniemulsion polymerization of methacrylate monomers. BM Teo, SW Prescott, M Ashokkumar and F Grieser. Ultrasonics Sonochemistry, 15(1), 89–94, 2008.

Last edited: Tuesday September 9, 2008

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