(131h) Characterizing Graphene Oxide Suspensions with Rheological Testing and Modeling, Neutron Scattering, and Electrochemical Performance
AIChE Annual Meeting
2020
2020 Virtual AIChE Annual Meeting
Particle Technology Forum
Engineered Particles and Nanostructured Particulate Systems Characterization
Tuesday, November 17, 2020 - 9:45am to 10:00am
Moreover, to understand the evolving microstructure, and its contribution to conductivity we incorporated rheological testing. The evolving microstructure of the graphene contributes to particle (sheet to sheet) interaction. Rheological data shows shear thinning with the graphene suspensions In addition, we show both the linear Small Amplitude Oscillatory Shear and nonlinear Large Amplitude Oscillatory Shear flow experiments as well as results of fitting and predicting the rheological flows with contemporary thixo-elasto-visco-plastic (TEVP) models. We will present our ultra-Small Angle Neutron Scattering results with USANS. From this we hypothesize that our material structure is linked to a breakdown of a hierarchical fractal structure in these suspensions. Preliminary Small Angle Neutron Scattering (SANS) and USANS measurements seem to validate this hypothesis. We show the graphene oxide suspension has a mid q feature that can be associated with the primary particle structure and a large upturn at low-q (inverse aggregate length scale) due to the formation of larger structures in the sample. In order to fully characterize the graphene-oxide we show a combination of SANS and USANS. We plan extract primary particle size, aggregate size and fractal dimension from the SANS/USANS data and correlate these properties directly to the conductivity and linear rheological properties.
Lastly will demonstrate a correlation between our rheological modelâs prediction of thixotropy, or microstructure with elastic and viscous features of our transient rheological data using Sequence of Physical Phenomena (SPP). We will show how the evolving microstructure contributes to the mechanical properties of the material with Cole-Cole plots. In addition, we will construct the full graphene oxide characterization with the USANS/SANS, rheological modeling, SPP framework analysis, and conductivity of the microstructure itself.
References
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[5] Hipp et al. JOR (2019).