Dr Xuehua Zhang - Summit Speaker Series - August 30, 2016

Dr. Xuehua Zhang     

Associate Professor RMIT University, Melbourne, Australia

Physics of Fluids group, Department of Applied Physics and J. M. Burgers Centre for Fluid Dynamics, University of Twente, 7500 AE Enschede, The Netherlands

Email: Xuehua.zhang@rmit.edu.au

 

Lecture #1: Formation of surface nanodroplets under controlled flow conditions

August 30, 2016

2:00 pm 8-207 Donadeo Innovation Centre for Engineering

When water is added into a clear Ouzo drink, the solution becomes cloudy due to the spontaneous formation of many oil microdroplets in the drink. This is the so-called ’Ouzo’ effect. Recently this daily phenomenon has drawn increasing interest, due to its complex fundamental aspects and practical relevance to flavour of drinks, lifetime of perfumes, and potential in functional nanomaterials and pharmaceutical products. This talk will discuss the nanodroplet formation from ouzo effect at a controlled mixing front during the solvent exchange. The formation of nanodroplets at solid-liquid interfaces during the solvent exchange process is influenced by the flow rate and the flow geometry on the droplet size. A theoretical framework is developed to account for these effects. The talk will also show the intriguing four different phases of an evaporating ouzo microdroplet and the physics which governs this phenomenon. Such Ouzo droplet may be seen as a model system for a ternary mixture of liquids with different volatilities and mutual solubilities. The understanding of phase separation on a sub-micron scale may open up numerous applications in chemical and biomedical analysis, coating or for the controlled deposition of tiny amounts of liquids.