Alignment of Worm-like Micelles at Intermediate and High Shear Rates

Published

February 1, 2020

Author(s)

Brisa Arenas-Gomez, Cristina Garza, Yun Liu, Rolando Castillo

Abstract

Hypothesis. Rheology combined with Small Angle Neutron Scattering (Rheo-SANS) can determine the local structural order in Worm-like Micelle (WLM) solutions, when the shear rate increases beyond the ending of the gradient shear banding, where the micellar solution is supposed to be alligned, it presents a second region with shear thinning. Experiments/i}. The mixture of 3-(N,N-dimethylmyristylammonio) propanesulfonate (TDPS), sodium dodecyl sulfate (SDS,) (R=[SDS]/[TDPS] = 0.55) in salty water, was studied with mechanical rheology and by Small Angle Neutron Scattering (SANS) in quiescent and flow. Findings. The system self-assembles WLMs and presents gradient shear banding. SANS patterns of the nonequilibrium phases are obtained along the shear banding in a Couette geometry along the 1-2 plane, and the orientation parameter along the gap. At very high shear rates in the paranematic phase, we found an apparent transition on the flow curves with its corresponding change in the orientation parameter. The origin of this transition is not clear, but we presented a possible explanation of why we observe them.

Citation

Journal of Colloid and Interface Science

Volume

560

Pub Type

Journals

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Keywords

Rheo-SANS, SANS, Worm-Like Micelle

Citation

Arenas-Gomez, B. , Garza, C. , Liu, Y. and Castillo, R. (2020), Alignment of Worm-like Micelles at Intermediate and High Shear Rates, Journal of Colloid and Interface Science, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928475 (Accessed October 31, 2024)