We present a reformulation of the ‘reactive rod model’ (RRM) of Dutta and Graham (2018), a constitutive model for describing the behavior of dilute wormlike micelle solutions. The RRM treats wormlike micelle solutions as dilute suspensions of rigid Brownian rods undergoing reversible scission and growth in flow. Evolution equations for micelle orientation and stress contribution are coupled to a kinetic reaction equation for a collective micelle length, producing dynamic variations in the length and rotational diffusivity of the rods. This model has previously shown success in capturing many critical steady-state rheological features of dilute wormlike micelle solutions, particularly shear-thickening and -thinning, non-zero normal stress differences, and a reentrant shear stress–shear rate curve, and could fit a variety of steady state experimental data. The present work improves on this framework, which showed difficulty in capturing transient dynamics and high-shear behavior, by reformulating the kinetic equation for micelle growth on a more microstructural (though still highly idealized) basis. In particular, we allow for micelle growth associated with strong alignment of rods and breakage due to tensile stresses along the micelles. This new formulation captures both steady and transient shear rheology in good agreement with experiments. We also find good agreement with available steady state extensional rheology.

我们提出了 Dutta 和 Graham（2018）的“反应棒模型”（RRM）的重新表述，这是一种用于描述稀释蠕虫状胶束溶液行为的本构模型。RRM 将蠕虫状胶束溶液视为刚性布朗杆的稀释悬浮液，在流动中经历可逆断裂和生长。胶束取向和应力贡献的演化方程与集体胶束长度的动力学反应方程耦合，产生杆的长度和旋转扩散率的动态变化。该模型先前已成功捕获稀蠕虫状胶束溶液的许多关键稳态流变特征，特别是剪切增稠和变稀、非零正应力差异和折返剪切应力-剪切速率曲线，并能拟合多种稳态实验数据。目前的工作通过在更微观结构（尽管仍然高度理想化）的基础上重新制定胶束生长的动力学方程，改进了这一框架，该框架显示出难以捕捉瞬态动力学和高剪切行为。特别是，我们允许与棒的强对齐相关的胶束生长以及由于沿胶束的拉伸应力而导致的断裂。这种新配方同时捕获了与实验非常一致的稳态和瞬态剪切流变学。我们还发现与可用的稳态拉伸流变学有很好的一致性。通过在更微观结构（尽管仍然高度理想化）的基础上重新制定胶束生长的动力学方程。特别是，我们允许与棒的强对齐相关的胶束生长以及由于沿胶束的拉伸应力而导致的断裂。这种新配方同时捕获了与实验非常一致的稳态和瞬态剪切流变学。我们还发现与可用的稳态拉伸流变学有很好的一致性。通过在更微观结构（尽管仍然高度理想化）的基础上重新制定胶束生长的动力学方程。特别是，我们允许与棒的强对齐相关的胶束生长以及由于沿胶束的拉伸应力而导致的断裂。这种新配方同时捕获了与实验非常一致的稳态和瞬态剪切流变学。我们还发现与可用的稳态拉伸流变学有很好的一致性。