nano - interfaces
Research in my group focuses on phenomena that occur when liquids are confined on the nano- and micro- scales. We conduct experiments in a wide range of fields, including: functional coatings, interfacial slip, superhydrophobic surfaces and nano- and micro-patterned coatings. We are interested in understanding fundamental physico-chemical mechanisms, and also in their application in bio- and nano-technology. Most of our research is multi-disciplinary, spanning the traditional disciplines of chemistry, physics, materials science and engineering, biology and bio-engineering. A broad range of surface characterisation techniques is employed, including atomic force microscopy (AFM), optical microscopy, neutron and X-ray reflectometry, ellipsometry, X-ray photoelectron spectroscopy, and contact angle goniometry. Research projects are available in the following general areas.
This project addresses the development of new chemically and topographically micro-patterned surfaces that can collect water from humid atmosphere. The surfaces are patterned using thin liquid film dewetting, which leads to the formation of isolated hydrophilic droplets on a hydrophobic background. The produced patterns mimic the surface structure that is present on a beetle native of the Namib desert, which collects drinking water on its micro-structured back. So far we have achieved collection rates of the order of 10 L/hour/square meter of surface. Future research could lead to the use of these coatings in the real-world, to provide decentralised and convenient water collection means to solve water shortage problems in our cities.
Slip at nanoparticles
This project addresses the fundamental problem of interfacial slip and aims at identifying the nano-scale interfacial properties that make surfaces slippery. Problems of profound importance in pure and applied surface science will be addressed, and its results will dramatically affect many other research fields, such as microfluidics, confined biological systems, and colloidal stability. This project consists in measuring the diffusion of nanoparticles in a liquid by using high-resolution nanoparticle characterisation techniques, such as light scattering. This will be done in collaboration with the National Measurements Institute in Lindfield, where nanoparticles standards are defined in Australia. We will evaluate the ability of different surface treatments to enhance the interfacial slip of liquids.
Water repellency is important in many technological applications, such as self-cleaning water-proof surfaces and microfluidic devices. The hydrophobicity of a surface can be enhanced by a chemical and topographical modification, which leads to an increase in the contact angle of a water drop, with values reaching the theoretical maximum of 180 degrees. We develop new approaches for the fabrication of superhydrophobic surfaces, and we investigate their potential applications. In this project we will collaborate with the surface coating industry to design novel superhydrophobic coatings and test their performance as self-cleaning coatings on the walls and roof of buildings.
Engineered wettability of snail shells
The surface structure of the shell of snails living in arid regions of South Australia has evolved to cope with extreme drought. In this project we investigate how nature has engineered the roughness and chemistry of the shell surface to optimise water collection by the snail, a natural engineering strategy that seems to be tailored to the particular microclimate in which the snails live, much like in the case of the wettability of plant leaves and insect wings. The study could provide an answer on the function of surface sculpturing in snail shells, and may provide biomimetic clues for the engineering of wettability in technological applications such as collection of water in arid environments.
Please feel free to come and talk to me and members of my group for further information.
School of Chemistry
University of Sydney NSW 2006
Phone: +61 2 9351 2752