MRI: Acquisition of a Confocal Microscope Rheometer for Structural Characterization of Complex Fluids & Soft Materials Under Shear

MRI：获取共焦显微镜流变仪用于复杂流体的结构表征

• 批准号: 1920156
• 负责人: Paulo Arratia
• 金额: $ 43.62万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1920156&HistoricalAwards=false
• 关键词: MRI; Acquisition; Confocal; Microscope; Rheometer

Complex fluids are a broad class of materials widely used in processes spanning the chemical, petroleum, pharmaceutical and food industries. They are also abundant in natural environments (for example, soil and mud) as well as in the human body (for example, mucus and reproductive fluids). Complex fluids may be considered 'soft', in the sense that they flow or distort easily in response to external forces. Many fascinating macroscopic responses of complex fluids containing particles, polymers, (bio)molecules, surfactants, or liquid crystals, have been widely reported in the literature. Characterizing the mechanical properties and microstructure of complex fluids and biological materials remains a challenge. The main issue is that one needs to precisely measure the material bulk response (or rheology) while simultaneously characterizing its microstructure. To that end, this project involves developing an instrument that incorporates a sensitive rheometer with a dynamic range that allows precise application of kinematic deformation coupled with a confocal microscope that provides real space, high-magnification, time-resolved spatial information in three dimensions. This research project aims to develop a confocal rheometer microscope by combining two commercially-available instruments, a confocal microscope and a stress-controlled rheometer. This new apparatus will allow researchers to impose precise kinematic deformation (i.e. shear, steady or time-dependent) onto a desired material while simultaneously characterizing the fluid microstructure and measuring the bulk fluid response. By incorporating both a high precision rheometer and a confocal microscope into one system, the project researchers will be able to conduct cutting edge experiments that relate 3-dimensional microstructure to bulk properties. The research project also could lead to new fundamental understanding of the mechanical and chemical forces that govern the dynamics of complex and soft materials and to new applications via the development of novel materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

复杂流体是广泛应用于化学、石油、制药和食品行业流程中的一大类材料。它们在自然环境（例如土壤和泥土）以及人体（例如粘液和生殖液）中也含量丰富。复杂的流体可以被认为是“软的”，因为它们响应外力而容易流动或变形。文献中广泛报道了含有颗粒、聚合物、（生物）分子、表面活性剂或液晶的复杂流体的许多令人着迷的宏观响应。表征复杂流体和生物材料的机械性能和微观结构仍然是一个挑战。主要问题是需要精确测量材料的体积响应（或流变学），同时表征其微观结构。为此，该项目涉及开发一种仪器，该仪器结合了具有动态范围的灵敏流变仪，可以精确应用运动变形，并结合共焦显微镜，提供真实空间、高放大倍率、三维时间分辨的空间信息。该研究项目旨在通过结合两种市售仪器（共焦显微镜和应力控制流变仪）来开发共焦流变仪显微镜。这种新设备将使研究人员能够对所需材料施加精确的运动变形（即剪切、稳定或随时间变化的变形），同时表征流体微观结构并测量整体流体响应。通过将高精度流变仪和共焦显微镜整合到一个系统中，该项目研究人员将能够进行将 3 维微观结构与整体特性联系起来的尖端实验。 该研究项目还可以带来对控制复杂和软材料动力学的机械和化学力的新的基本理解，并通过新型材料的开发带来新的应用。该奖项反映了 NSF 的法定使命，并被认为值得通过以下方式获得支持：使用基金会的智力价值和更广泛的影响审查标准进行评估。

项目成果

A homogenization model for the rheology and local field statistics of suspensions of particles in yield stress fluids

屈服应力流体中颗粒悬浮液的流变学和局部场统计的均质化模型

• DOI: 10.1122/8.0000337
• 发表时间: 2022-05
• 期刊: Journal of Rheology
• 影响因子: 3.3
• 作者: Kammer, Christoph;Blackwell, Brendan;Arratia, Paulo E.;Ponte Castañeda, Pedro
• 通讯作者: Ponte Castañeda, Pedro