Controlling the organisation of matter using thin film microfluidics

Professor Colin L. Raston

SA Premier’s Professorial Research Fellow in Clean Technology, ARC Australian Professorial Fellow School of Chemical and Physical Sciences, , Bedford Park, SA 5042. [email protected]

We have developed the use of microfluidic platforms based on dynamic thin films in chemical and materials synthesis. Initially we focused on the application of a spinning disc processor (SDP), followed by a rotating tube processor (RTP), where the residence time of the processing can be controlled to up to a minute, overcoming the limited processing time for SDP, which is typically < 1 sec for a 10 cm disc operating at 2500 rpm. The dynamic thin films in these platforms allow exquisite control over the size, shape, agglomerations, phases, and indeed defects of nano-particles, as well as the ability to coat preformed nano-particles in a controlled way.1 They also have application in the top down fabrication of graphene and h- BN scrolls,2 controlling chemical reactivity and selectivity, and controlling the disassembly of self organised systems, under continuous flow conditions.3 This control relates to the intense shear of the thin films arising from the viscous drag as the liquid accelerates on the disc of an SDP, or whirls down the tube of the RTP. Recently we developed a vortex fluidic device (VFD),4 as a versatile continuous flow processor, where the residence time can be controlled, with the ability to scale down to sub- millilitre volumes with an optional sequential ‘confined mode’, and the ability to scale up to large volumes. VFD is also inexpensive relative to SDP and RTP, and we have used the platform for controlling the growth of metal nano-particles, including on graphene,5 wrapping single cell algae with graphene,6 and more.

1. Nanorings of self-assembled C70 as templating nanoreactors, K. S. Iyer, M. Saunders, T. Becker, C. Evans and C. L. Raston, J. Am. Chem. Soc, 2009, 131, 16338. 2. Shear induced formation of carbon and boron nitride nano-scrolls, Xianjue Chen, Ramiz A. Boulos, John F. Dobson and Colin L. Raston, Nanoscale, 2013, 5, 498–502. 3. Loading molecular hydrogen cargo within virus like containers, K. S. Iyer, M. Norret, S. J. Dalgarno, J. L. Atwood, and C. L. Raston., Angew. Chem. Int. Ed., 2008, 47, 6362. 4. Optimising a vortex fluidic device for controlling chemical reactivity and selectivity, L. Yasmin, X. Chen, K. A. Stubbs and C. L. Raston, Scientific Reports, 2013, 3, 2282. 5. Vortex fluidic exfoliation of graphite and boron nitride, X. Chen, J. F. Dobson and C. L. Raston, Chem. Commun., 2012, 48, 3703 6. Functional multi-layer graphene–algae hybrid material formed using vortex fluidics, M. H. Wahid, E. Eroglu, X. Chen, S. M. Smith and C. L. Raston, Green Chem., 2013, 15, 650 Biography:

Prof Colin Raston is a SA Premier’s Professorial Research Fellow in Clean Technology and an ARC APF at Flinders University He has previously held Chairs of Chemistry at , , The University of Leeds, and The University of Western Australia. He is a former President, Queensland Branch President, and Chair of the Inorganic Division, the Royal Australian Chemical Institute (RACI). He has received the RACI’s Challenge Award, the H.G. Smith Award, the Burrows Award, and the Leighton Memorial Award, and is a former recipient of an ARC Special Investigator Award and ARC Senior Research Fellowships. His current research covers clean technology and green chemistry, process intensification, nanotechnology and self-assembly, and is currently on the editorial advisory editorial boards of the journals Green Chemistry and RSC Advances, and on the editorial board of Crystal Growth and Design.