We have conducted comprehensive rheological and rheo-birefringence characterizations of a series of semidilute ethyl cellulose (EC)/α-terpineol dispersions under steady shear flow. The EC dispersions investigated have commonly been utilized as a binder agent in fabricating metal/metal-oxide pastes for a number of industrial applications, and were recently demonstrated to foster nearly monodisperse spherical aggregates under dilute conditions. Herein, semidilute EC dispersions are shown to exhibit rheological features practically no different from those known for standard entangled polymer solutions. The corresponding rheo-birefringence responses, however, reveal microstructural features that are reminiscent of general colloidal systems. The steady-state feature reveals a universal stress-birefringence relationship at various EC concentrations, along with a common critical stress (∼200 Pa) at which the EC network breaks into smaller clusters. The transient feature displays prominent and long-persisting periodic oscillations that have previously been observed only for nearly monodisperse rod-like colloids or liquid crystals. The overall findings shed new light on the role of EC serving as a commonplace polymer binder in industry and, from a scientific perspective, raise interesting questions related to the characteristic rheological and microstructural features of general polymer dispersions in overlapped regimes.

中文翻译：

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半稀释乙基纤维素分散体在稳定剪切流下的流变和流变双折射特性。

我们已经进行了一系列在稳定剪切流下的半稀释乙基纤维素（EC）/α-萜品醇分散体的流变和流变双折射表征。所研究的EC分散体通常在许多工业应用中用作制造金属/金属氧化物浆料的粘合剂，最近被证明可在稀薄条件下促进几乎单分散的球形聚集体。在本文中，半稀释的EC分散体显示出流变特性，实际上与标准缠结聚合物溶液的流变特性没有什么不同。然而，相应的流变双折射响应揭示了微观结构特征，使人联想到一般的胶体系统。稳态特性揭示了在各种EC浓度下普遍的应力-双折射关系，以及共同的临界应力（约200 Pa），在该应力下EC网络会破裂成较小的簇。瞬态特征显示出突出且持久的周期性振荡，以前仅对几乎单分散的棒状胶体或液晶观察到过。总体发现为EC在工业中作为普通聚合物粘合剂的作用提供了新的视角，并且从科学的角度出发，提出了与重叠状态下一般聚合物分散体的特征流变学和微观结构特征有关的有趣问题。