Paper Number
PS20
Session
Polymers in Solution
Title
Shear rheology of carbon nanotubes in chlorosulfonic acid
Presentation Date and Time
October 16, 2018 (Tuesday) 1:55
Track / Room
Track 4 / Post Oak
Authors
- Rosa de Siqueira, Ivan (Rice University, Department of Chemical and Biomolecular Engineering)
- Dewey, Oliver S. (Rice University, Department of Chemical & Biomolecular Engineering)
- Taylor, Lauren W. (Rice University, Department of Chemical & Biomolecular Engineering)
- Bengio, Elie A. (Rice University, Department of Chemical & Biomolecular Engineering)
- Pasquali, Matteo (Rice University, Department of Chemical & Biomolecular Engineering)
Author and Affiliation Lines
Ivan Rosa de Siqueira, Oliver S. Dewey, Lauren W. Taylor, Elie A. Bengio, and Matteo Pasquali
Department of Chemical & Biomolecular Engineering, Rice University, Houston, TX 77005
Speaker / Presenter
Rosa de Siqueira, Ivan
Text of Abstract
Carbon nanotubes (CNTs) have been widely used in the development of new materials, such as macroscopic fibers, thin films, and aerogels. The macroscopic materials with the best properties are based on liquid-phase processing of CNTs dispersed in superacids. Therefore, process optimization relies on fundamental understanding of the mechanical response and rheological behavior of these complex solutions under flow. In this work, we present an experimental study on the shear rheology of CNTs dispersed in chlorosulfonic acid (CSA). The experiments were conducted in a cylindrical Couette geometry with a setup to avoid the chemical reaction between the superacid solvent and moisture in the air. Experiments performed for different aspect ratios over a wide range of concentrations elucidate the highly non-Newtonian behavior of CNT/CSA solutions. Dynamic tests show the viscoelastic response of CNT/CSA solutions within the linear viscoelastic regime in terms of both elastic and viscous moduli. A rigorous pre-shear methodology is used together with small amplitude oscillatory tests to estimate the material relaxation time and avoid memory effects between two consecutive measurements. Furthermore, steady-state tests highlight the strong shear rate-dependent viscosity of CNT/CSA solutions under shear flows.