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Updated: Jun 17, 2025
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Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures
Published on: May 20, 2014
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Quantifying electron transport in aggregated colloidal suspensions in the strong flow regime
Julie B Hipp1, Paolo Z Ramos2, Qingsong Liu2
1Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716.
Summary
Electron transport in flowing composites is linked to microstructure and dynamics. This study reveals shear-enhanced particle collisions dominate electron transport in conductive carbon black suspensions.
Area of Science:
- Soft matter physics
- Colloidal science
- Electrochemistry
Background:
- Electron transport in complex fluids is crucial for redox reactions and energy storage.
- Conductor-insulator composites' electrical properties depend on conductive phase microstructure and dynamics.
- A unified description of these effects, especially under flow, is lacking.
Purpose of the Study:
- To develop a unified description of electron transport in flowing conductive colloidal suspensions.
- To investigate the interplay between microstructure, dynamics, and electrical properties under shear.
- To rationalize conflicting literature data on shear-dependent electrical properties.
Main Methods:
- Measured conductivity and shear viscosity of carbon black (CB) particle suspensions.
- Utilized Mason number to identify equivalent microstructural states under varying flow conditions.
- Analyzed flow-induced dynamics and their impact on electron transport.
Main Results:
- Observed competing relationships between conductivity and shear rate.
- Demonstrated that shear-enhanced particle-particle collisions are the dominant factor in electron transport at equivalent microstructural states.
- Successfully isolated the role of dynamics on flow-induced electron transport.
Conclusions:
- Electron transport in flowing composites is governed by shear-enhanced particle collisions.
- The Mason number effectively normalizes microstructural states in flowing suspensions.
- This work provides a unified framework for understanding electrical properties in dynamic composite systems.
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