发表机构
Tokyo University of Agriculture and Technology; King Abdullah University of Science and Technology; Shinshu University（东京农工大学; 阿卜杜拉国王科技大学; 信州大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过纤维素纳米晶悬浮液的流变-光学实验和福克-普朗克模型，发现应力-光学规则的表观失效源于应力分配而非材料系数，参照布朗应力可统一不同条件下的响应。
AI 中文摘要
各向异性大分子材料领域的一个基本问题涉及流动诱导的取向有序如何将微观结构与宏观流变应力和光学各向异性联系起来。本研究将纤维素纳米晶悬浮液作为刚性棒模型系统，以将取向效应与链拉伸效应分离开来。通过同时进行的流变-光学测量，获取了双折射、取向角和剪切应力数据，并结合福克-普朗克取向模型和应力分解进行分析。我们的结果表明，在佩克莱特数较低时，双折射与总应力表现出类似于应力-光学规则的正比关系。然而，浓度依赖性表明，这种正比关系反映的是应力分配，而非唯一的材料系数。随着流动强度的增加，取向饱和伴随着布朗应力相对贡献的减少，以及基于总应力的关系发生相应变化。将光学响应参照于估算的布朗应力贡献，可以在不同浓度和流动条件下获得显著更统一的响应，从而支持对表观应力-光学规则失效的应力分配解释。
英文摘要
A fundamental problem in the field of anisotropic macromolecular materials concerns how the flow-induced orientational order connects microscopic structure to macroscopic rheological stress and optical anisotropy. This study considered cellulose nanocrystal suspensions as rigid-rod model systems for the purpose of isolating orientational effects from chain stretching. Simultaneous rheo-optical measurements of birefringence, orientation angle, and shear stress were combined with a Fokker-Planck orientation model and stress decomposition. Our results show that, at low values of the Peclet number, birefringence and total stress exhibit proportionality similar to the stress-optic rule. However, the concentration dependence indicates that this proportionality reflects stress partitioning rather than a unique material coefficient. With increasing flow strength, orientational saturation is accompanied by a reduced relative Brownian stress contribution and a corresponding change in the total stress-based relation. Referencing the optical response to an estimated Brownian stress contribution yields a substantially more unified response across concentrations and flow conditions, supporting a stress-partitioning interpretation of apparent stress-optic rule breakdown.
Comments23 pages, 12 figures, 1 table
