AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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Determination of Mass Mobility Exponent and Fractal Dimension of Crumpled Graphene Oxide Synthesized in a Furnace Aerosol Reactor (FuAR)
SHALINEE KAVADIYA, Yao Nie, Pratim Biswas, Washington University in St. Louis
Abstract Number: 144 Working Group: Nanoparticles and Materials Synthesis
Abstract Crumpled graphene oxide (CGO) was synthesized to overcome the restacking issue of two-dimensional (2D) graphene oxide (GO) sheets. CGO has gained immense attention because of their dispersion as a single crumpled ball, their ability to encapsulate metal/metal oxide nanoparticles and make composite nanomaterials for various applications. CGO particles are mainly synthesized by aerosol-based processes, in which 2D GO sheets are aerosolized into droplets and dried either at room temperature1 (in the case of small droplets generated by electrospray) or inside a furnace reactor at high temperature2 (in the case of big droplets generated by nebulizer). Evaporation of the solvent imparts a capillary force on the GO sheet and induces crumpling. Until now, the mechanism of crumpling and the estimation of force required for GO crumpling has been explained based on the macroscale system such as paper and foils. However, the nanoscale system of GO sheets is significantly different from the macroscale system.
In this study, we synthesize the CGO particles using a furnace aerosol reactor and correlate the mass mobility of the CGO particles to their mobility size, physical size and the morphology (extent of crumpling). Mobility size of the particles is measured online using scanning mobility particle sizer (SMPS), then particles of a particular size are classified using differential mobility analyzer and passed through a centrifugal particle mass analyzer (CPMA) to measure the mobility mass. Finally, a size (and crumpling) - dependent mass mobility exponent is calculated. Crumpling of GO sheets depends on the various parameters such as, furnace temperature and GO concentration. We study the effect of these parameters on the mass mobility exponent. Since the expression of force required for crumpling also depends on the fractal dimension of crumpled particle, fractal dimension of CGO is measured using Small Angle X-ray Scattering (SAXS) technique. Finally, a relationship between the fractal dimension and the mass mobility exponent for CGO particles is derived.
References: 1. Kavadiya et al., J. Nanopart. Res., 2017, 19, 43 2. Wang et al., J. Phys. Chem. Lett., 2012, 3, 3228.