Nonlinear rheology of entangled wormlike micellar solutions predicted by a micelle-slip-spring model
Nonlinear rheology of entangled wormlike micellar solutions predicted by a micelle-slip-spring model
复制标题
用胶束-滑移-弹簧模型预测缠结蠕虫状胶束溶液的非线性流变学
DOI：
10.1122/8.0000426
复制
发表时间：
2022-05-01
影响因子：
3.3
通讯作者：
Larson, Ronald G.
中科院分区：
文献类型：
--
作者：
Sato, Takeshi;Larson, Ronald G.
我们使用“胶束-滑移-弹簧模型”来研究线性和非线性剪切和拉伸流变性[T.Sato等人，J.流变学。，1045-1061(2020年)]，该模型将断裂和重新连接事件纳入到最初由Likhtman[大分子38,6128-6139(2005)]为不可破碎聚合物开发的滑动弹簧模型中。在这里，我们使用主链弹簧和滑移弹簧的Fraenkel势来处理有限延伸性的影响。此外，为了改善在强拉伸流下的拉伸性能，在胶束-滑移-弹簧模型中引入了应力诱导胶束破裂(SIMB)。因此，该模型是第一个包含纠缠约束、Rouse模、有限延伸性、破裂和重合事件以及应力诱导胶束破裂的模型。目前的计算费用将模型限制在中等数量的纠缠胶束解(&LSIM；7)，但对于这样的解，剪切流的启动几乎达到了定量的一致。由于缺乏这种纠缠水平的数据，伸展流动中的模型还不能进行测试。胶束-滑移-弹簧模型预测的中等剪切速率区的稳态剪切性质与Giesekus模型吻合较好，但与Phan-Thien/Tanner(PTT)模型不符合，这与Giesekus模型对实验剪切数据的拟合能力是一致的。SIMB胶束-滑移-弹簧模型测得的拉伸粘度呈现先增后稀的变化趋势，定性上与实验趋势一致。此外，无论有无SIMB，Giesekus模型和PTT模型都不能很好地预测胶束-滑移-弹簧模型的拉伸流变性质。因此，未来的工作应该寻求一种本构模型，能够捕捉剪切和拉伸流动中滑动弹簧模型的行为，从而提供一个准确、有效的胶束溶液流变学模型。
We examine linear and nonlinear shear and extensional rheological properties using a "micelle-slip-spring model " [T. Sato et al., J. Rheol. 64, 1045-1061 (2020)] that incorporates breakage and rejoining events into the slip-spring model originally developed by Likhtman [Macromolecules 38, 6128-6139 (2005)] for unbreakable polymers. We here employ the Fraenkel potential for main chain springs and slip-springs to address the effect of finite extensibility. Moreover, to improve extensional properties under a strong extensional flow, stress-induced micelle breakage (SIMB) is incorporated into the micelle-slip-spring model. Thus, this model is the first model that includes the entanglement constraint, Rouse modes, finite extensibility, breakage and rejoining events, and stress-induced micelle breakage. Computational expense currently limits the model to micellar solutions with moderate numbers of entanglements ( & LSIM; 7), but for such solutions, nearly quantitative agreement is attained for the start-up of the shearing flow. The model in the extensional flow cannot yet be tested owing to the lack of data for this entanglement level. The transient and steady shear properties predicted by the micelle-slip-spring model for a moderate shear rate region without significant chain stretch are fit well by the Giesekus model but not by the Phan-Thien/Tanner (PTT) model, which is consistent with the ability of the Giesekus model to match experimental shear data. The extensional viscosities obtained by the micelle-slip-spring model with SIMB show thickening followed by thinning, which is in qualitative agreement with experimental trends. Additionally, the extensional rheological properties of the micelle-slip-spring model with or without SIMB are poorly predicted by both the Giesekus and the PTT models using a single nonlinear parameter. Thus, future work should seek a constitutive model able to capture the behavior of the slip-spring model in shear and extensional flows and so provide an accurate, efficient model of micellar solution rheology.& nbsp; (C)& nbsp;2022 The Society of Rheology.