A temperature-controlled submillimeter-gap (500 μm) rheo-magnetic resonance imaging (MRI) Couette cell has been developed to measure confined flow of soft structured materials under controlled temperature. The proposed setup enables performing rheo-MRI measurements using (i) a spatially uniform temperature control over the range 15°C to 40°C and (ii) a high spatial resolution up to 10 μm, as a consequence of the improved mechanical stability of the in-house developed rotating elements. Here, we demonstrate the performance of the cell for the rheo-MRI velocimetry study of a thixotropic fat crystal dispersion, a complex fluid commonly used in food manufacturing. The submillimeter-gap geometry and variable temperature capability of the cell enable observing the effects of shear- and temperature-induced fat recrystallization on both wall slip and shear banding under strongly confined flow. Our improved rheo-MRI setup opens new perspectives for the fundamental study of strongly confined flow, cooperative effects, and the underlying interparticle interactions and for ultimately aiding optimization of products involved in spreading/extrusion, such as cosmetics and foods.

中文翻译：

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在亚毫米间隙 Couette 几何中验证温度控制的 rheo-MRI 测量

开发了一种温度受控的亚毫米间隙 (500 μm) 流变磁共振成像 (MRI) Couette 池，用于在受控温度下测量软结构材料的受限流动。所提出的设置能够使用 (i) 在 15°C 至 40°C 范围内的空间均匀温度控制和 (ii) 高达 10 μm 的高空间分辨率来执行 rheo-MRI 测量，这是由于改进的机械稳定性的结果内部开发的旋转元件。在这里，我们展示了细胞在触变性脂肪晶体分散体的流变 MRI 测速研究中的性能，这是一种常用于食品制造的复杂流体。电池的亚毫米间隙几何形状和可变温度能力能够观察剪切和温度诱导的脂肪再结晶对强限制流动下的壁滑移和剪切带的影响。我们改进的 rheo-MRI 设置为强约束流动、协同效应和潜在的粒子间相互作用的基础研究开辟了新的视角，并最终有助于优化涉及扩散/挤出的产品，例如化妆品和食品。