News: News, Research, SA

Spinning carbon into shape

In 2015 Prof. Colin Raston from Flinders University won the Ig Nobel Prize for the development of a ‘Vortex Fluidic Device’ (VFD) that can unboil an egg. This feat grabbed world headlines and demonstrates a seriously useful invention.

The VFD can be used to refold misshapen proteins, produce biodiesel from waste oils, modify the characteristics of wine and facilitate a range of different chemical transformations. Prof. Raston’s group is using the VFD to create carbon nanostructures that could increase the efficiency of solar cells and improve polymer composites, sensing devices, electronics and drug delivery.

PhD student Kasturi Vimalanathan is working with Prof. Raston on these carbon nanostructures, which are made of graphene; single layers of graphite. Single-walled carbon nanotubes (SWCNT) can be cut into specific lengths by using a pulsed laser with various solvents and altered shear forces in the VFD. The VFD can also bend SWCNTs into rings without reactive chemicals or stabilising surfactants. The diameter of the nanorings is controllable; either from 100 to 200 nm or 300 to 700 nm and production can be readily scaled up.

Ms Vimalanathan has also used the VFD to assemble nanoscale carbon spheres, commonly known as buckyballs (C60), into crystalline nanotubules without stabilising agents and without trapping solvent molecules during crystallisation. The VFD efficiently controls the assembly and can form micrometre-length nanotubules with a hollow diameter of 100-400nm.

During these manipulations, atomic force microscopy and scanning electron microscopy in the AMMRF (now Microscopy Australia) at Flinders University were used to visualise and measure the nanoscale products.

Atomic force microscopy shows SWCNT (left), SWCNT rings (centre). Right: SEM image of buckyball tubules.