Two-fluid model for nonlinear flow of wormlike micelle solutions. I: Model

Published

November 1, 2024

Author(s)

Paul Salipante, Michael Cromer, Steven D. Hudson

Abstract

We develop a rheological model to approximate the nonlinear rheology of wormlike micelles using two constitutive models to represent a structural transition at high shear rates. The model is intended to describe the behavior of semidilute wormlike micellar solutions over a wide range of shear rates whose parameters can be determined mainly from small-amplitude equilibrium measurements. Length evolution equations are incorporated into reactive Rolie-Poly entangled-polymer rheology and dilute reactive-rod rheology, with a kinetic exchange between the two models. Although the micelle length is remarkably reduced during flow, surprisingly, we propose that they are not shortened by stress-enhanced breakage, which remains thermally driven. Instead, we hypothesize that stretching energy introduces a linear potential that decreases the rate of recombination and reduces the mean micelle length. This stress-hindered recombination approach accurately describes transient stress-growth upon start-up shear flow, and it predicts a transition of shear viscosity and alignment response observed at high shear rates. The proposed mechanism applies only when self-recombination occurs frequently. The effect of varying the relative rate of self-recombination on the rheology of wormlike micelles at high shear rates is yet to be explored.

Citation

Journal of Rheology

Volume

68

Issue

6

Pub Type

Journals

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Keywords

Wormlike Micelles, Surfactants, Modeling

Citation

Salipante, P. , Cromer, M. and Hudson, S. (2024), Two-fluid model for nonlinear flow of wormlike micelle solutions. I: Model, Journal of Rheology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956499 (Accessed November 21, 2024)