Soft condensed matter physics

• Professor Peter Daivis, School of Science, RMIT

• Professor Marilyn Ball, Functional Ecology Group, Australian National University, Canberra
• Dr Chris Garvey, Bragg Insitute, ANSTO
• Dr Ricardo Mancera, School of Biomedical Sciences, Curtin University
• Dr Stephen Williams, Research School of Chemistry, Australian National University, Canberra

• Professor Karen Koster, University of South Dakota, USA
• Dr Eric Perez, Ecole Normale Supérieure, Paris, France
• Dr Hans Joachim Schöpe, University of Tübingen, Tübingen, Germany
• Professor Wilson Poon, School of Physics, University of Edinburgh
• Dr Vincent Martinez, School of Physics, University of Edinburgh
• Dr Ben Kent, Helmholtz-Zentrum Berlin für Materialien und Energie, Potsdam, Germany
• Dr Thomas Hauss, Helmholtz-Zentrum Berlin für Materialien und Energie, Potsdam, Germany

Research goals

• To understand crystallization, melting and the glass transition at a fundamental level.
• To develop improved experimental methods for the study of crystallization and glass formation in colloidal systems.
• To understand the effects of polydispersity on colloidal crystallization.
• To develop methods for influencing the type and rate of colloidal crystallization using external fields.

Methods

• Dynamic light scattering (DLS) and Static Light Scattering (SLS)
• Bragg crystallography
• Molecular Dynamics Simulations

This video (MP4, 2.4 MB, 1 min) shows a time lapse of crystallization followed by settling of the crystals under gravity. The right hand sample shows heterogeneous crystal growth.

We also conduct studies in 2 dimensional systems. This video (MP4, 1 MB, 11 seconds) shows 2-D Brownian motion in a dense 2-D fluid of particle trapped at an interface between 2 liquids.

Applications

• Much of our research is focussed on improving our understanding of the fundamental processes of crystallization and the glass transition, an area of classical physics which is still poorly understood.
• A better understanding of these processes is of importance for a range of industries in the are of materials science.
• Colloidal crystals have significant potential as the basis for optical devices and other nanotechnologies.

Research goals

• To understand how biological membranes respond to changes in water content, with emphasis on understanding the mechanisms of desiccation and freezing damage.
• To understand the physical mechanisms behind the ability of a range of solutes to limit damage to biological cells during freezing and/or dehydration.
• To understand the behaviour of biological water glasses under conditions used for cryopreservation of medical tissue.
• To be able to predict the longevity of biological tissue stored in a frozen or dehydrated state.

For more detailed information on Cryobiology, visit the cryobiology and anhydrobiology of cells web page prepared by Professor Joe Wolfe (School of Physics, UNSW) and Professor Gary Bryant (School of Applied Sciences, RMIT).

We also work with ecologists and plant physiologists to understand freezing, desiccation and heat stress in plants. A recent example is outlined in this paper published in Plant Physiology.

Methods

• Small angle X-ray diffraction (SAXS), including synchrotron SAXS
• Small angle Neutron scattering (SANS)
• Differential Scanning Calorimetry (DSC)
• Solid State Nuclear Magnetic Resonance (SSNMR)
• Dynamic light scattering (DLS) and Static Light Scattering (SLS)

Applications

• Agronomy – development of crops and plants with frost/drought resistance
• Genetic resources preservation (DNA, seeds, sperm, eggs...)
• Medical cryopreservation for transplants, transfusions, IVF etc
• Cryopreservation of cell lines for a range of medical research, including research into cancer.

We currently have a range of research projects underway which make use of scattering techniques. These include:

• The study of biological and non-biological macromolecules (proteins, polymers etc) using Dynamic Light Scattering combined with small angle Neutron, X-ray and Light scattering techniques. These techniques are important for the determination of the size and shape of macromolecules in solution, and for studying how the molecular size and shape are influenced by changing conditions (pH, temperature etc).
• A study of the effects of sugars, proteins and other molecules on the structure of biological membranes using small angle X-ray and Neutron scattering.

PhD students

• Catherine Carnovale (PhD - submitted) – Investigation of shape and size effects on the efficacy and toxicity of nanoparticles (with Associate Professor Vipul Bansal and Dr Ravi Shukla)
• Professor Ricardo Mancera, Curtin and Dr Chris Garvey, ANSTO).
• Uzma Malik (Masters) – Interactions of phospholipid membranes with DMSO and Isoprene. (with Dr Chris Garvey, ANSTO).
• Reece Nixon-Luke (PhD) – Differential Dynamic Microscopy and Dynamic Light Scattering studies of Bacterial Motility (with Dr Vincent Martinez, University of Edinburgh).
• Stephen Hannam (PhD) - Investigation of crystallization inhibitors through molecular dynamics simulation (with Senior Supervisor Professor Peter Daivis)

PhD students

• Dr Ben Kent – 2011 Effect of sugars of the lamellar-inverse hexagonal phase transition in biological membranes (with Dr Chris Garvey, ANSTO). Now at the Helmholtz-Zentrum Berlin für Materialien und Energie, Potsdam, Germany.
• Dr Vincent Martinez – 2009 Slow dynamics and ageing behaviour in colloidal suspensions near the glass transition (with Emeritus Professor William van Megen). Now at the School of Physics, University of Edinburgh.
• Dr Thomas Lenné – 2008 The effects of Solutes on the phase transitions of phospholipid membranes (with Professor Karen Koster, University of South Dakota, USA and Dr Chris Garvey, ANSTO). Now at the Australian Transport Safety Bureau (ATSB).
• Dr Olivier Marnette – 2007 Phase transitions in polydisperse two dimensional hard sphere colloids (at the Laboratoire de physique statistique, Ecole Normale Supérieure, Paris, France, with Dr Eric Perez). Now with the French Ministry of Education in French Guyana.
• Dr Terry O'Bree – 2007 An investigation of the Volume Scattering Functions of Australian natural waters for remote sensing purposes (with Arnold Dekker, CSIRO Land and Water). Now at the Australian Transport Safety Bureau (ATSB).
• Dr Stephen Martin – 2002 Crystallisation of Polydisperse Hard-Sphere Colloidal Systems (with Emeritus Professor William van Megen). Now at the Australian Synchrotron.
• Dr Tim Mortensen – 2002 Glass Transition Dynamics in Hard Sphere Suspensions (with Emeritus Professor William van Megen). Now at Infosys.
• Dr Stephen Williams – 2001 The Effect of Polydispersity on the Hard Sphere Glass Transition (Emeritus Professor William van Megen and Professor Ian Snook). Now at the Australian National University.
• Dr Suparno – 2000 (at the University of South Australia with Professor John Thomas)? Charging Behaviour in a non-polar colloidal system. Now at the University of Yogyakarta, Indonesia.
• Dr Stuart Henderson – 1999 Crystallisation From The Melt, a study of Polydisperse Hard Sphere Colloids. Now at the Australian Radiation Protection and Nuclear Safety Agency.

Master of Applied Science

• Jason Walsh – 2010 Structured Light Fields for the Creation of Colloidal Crystals. (with Associate Professor Phil Wilksch)
• Mr Joe Harland – 1998 Kinetics of the Fluid to Crystal Transition in Dense, Hard Sphere, Colloidal Suspensions. Now Retired.
• Master of Technology Mr Phil Francis – 2002 A Bragg Scattering Spectrometer. Now Manager of Electron Microscopy at the RMIT Microscopy and Microanalysis Facility (RMMF) at RMIT.

The major pieces of equipment are:

• A Bruker microfocus Small angle X-ray Scattering (SAXS) instrument. Has capabilities for SAXS and WAXS, with simultaneous DSC. Includes cells for powders, solids, liquids and a flow through cell. Further details can be found here.
• An ALV - two colour cross-correlation multiple-scattering-suppression spectrometer. This instrument is unique in the world, and is capable of dynamic and static light scattering measurements in suspensions which are too turbid for normal light scattering.
• An ALV – 5022F FAST correlator and compact goniometer. Facility for Static and Dynamic Light Scattering, Zimm plots, Particle size distribution determination, Depolarized light scattering, Fast correlation capability. Capable of measuring size and shape of nanoparticles in solution from spheres to rods.
• An ALV Compact goniometer, with motorised detector suitable for static and dynamic light scattering. Optimised for the study of very slow dynamics in colloids and gels.
• An RMIT built Bragg angle spectrometer (for studying crystallisation kinetics in colloidal suspensions).

In addition to our local facilities, we use the following facilities at RMIT and elsewhere:

• RMIT Microscopy and Microanalysis Facility
• RMIT X-ray Facility
• RMIT Thermal Analysis Facility

We also make use of major neutron and x-ray scattering facilities, both in Australia and overseas:

• Australian Nuclear Science and Technology Organization (ANSTO), Lucas Heights, Sydney
• Australian Synchrotron, Clayton, Melbourne
• European Synchrotron Radiation Facility (ESRF), Grenoble, France
• Helmholtz-Zentrum Berlin für Materialien und Energie, Potsdam, Germany
• Geesthacht Neutron Facility (GeNF), Geesthacht, Germany
• NIST Center for Neutron Research, Maryland, USA
• Advanced Photon Source, Argonne National Laboratory, USA
• Institut Laue-Langevin, Grenoble, France