Role of Composition on Mesostructure-Flow Interaction and Rheology of Particle Laden Interfaces

成分对细观结构-流动相互作用和颗粒负载界面流变学的作用

• 批准号: 1437710
• 负责人: Gordon Christopher
• 金额: $ 29.49万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1437710&HistoricalAwards=false
• 关键词: Role; Composition; Mesostructure; Flow; Interaction

CBET-1437710The physical properties of suspensions such as emulsions and foams can be strongly affected by the presence of small particles that adsorb onto liquid-liquid or liquid-gas interfaces. This project will explore how the presence of adsorbed particles, their composition, and the arrangements they can take on an interface, which is called their mesostructure, can influence the rheology of the interface. An interfacial rheometer has been developed for this study, which will allow investigators to measure characteristics of the interface and simultaneously observe particles at the interface. The results will be used to determine the role of mesostructures on interfacial rheology. This relationship between structure and rheology is important, because many manufacturing chemical processes found in consumer cosmetics, food products, drug delivery applications, and enhanced oil recovery use emulsions that have particle-laden or particle-covered interfaces. The information gathered in this project will be useful to scientists and engineers who formulate such products and design large-scale processes to manufacture them. The investigators will use results from the project to develop a series of informative and engaging modules that can be used by instructors to teach fluid dynamics principles to university and middle-school students.The mesostructure in particle-laden interfaces are affected by interparticle forces, which depend on composition. The mesostructure resists flow-induced deformation, resulting in an interfacial viscoelasticity. The nature of particle interactions on an interface differs from that in the bulk, primarily because of an anisotropic capillary attraction between interfacial particles. Using the interfacial rheometer, investigators will characterize the role of composition on the equilibrium mesostructure of particle-laden interfaces, characterize the role of composition on the rheology and mesostructure of deforming interfaces, and relate changes in composition such as particle surface concentration, particle size and polydispersity, and surfactant concentration to interparticle forces and viscous forces. Viscoelasticity of such interfaces affects dynamical behavior of emulsions, including drop deformation, coalescence and breakup. Understanding the relationship between composition and rheology will allow practitioners to tailor interfaces and engineer materials with desired properties.

CBET-1437710 悬浮液（例如乳液和泡沫）的物理性质会受到吸附在液-液或液-气界面上的小颗粒的强烈影响。 该项目将探索吸附颗粒的存在、它们的组成以及它们在界面上的排列（称为介观结构）如何影响界面的流变学。 本研究开发了界面流变仪，使研究人员能够测量界面的特性，同时观察界面处的颗粒。 结果将用于确定介观结构对界面流变学的作用。 结构和流变学之间的这种关系很重要，因为消费化妆品、食品、药物输送应用和提高采收率中的许多制造化学过程都使用具有充满颗粒或颗粒覆盖界面的乳液。 该项目中收集的信息将对配制此类产品并设计大规模制造工艺的科学家和工程师有用。 研究人员将利用该项目的结果开发一系列信息丰富且引人入胜的模块，教师可以使用这些模块向大学和中学生教授流体动力学原理。颗粒负载界面中的介观结构受到颗粒间力的影响，颗粒间力会影响颗粒间的相互作用。取决于成分。 细观结构抵抗流动引起的变形，从而产生界面粘弹性。界面上颗粒相互作用的性质与本体中的不同，主要是由于界面颗粒之间的各向异性毛细管吸引力。 使用界面流变仪，研究人员将表征成分对充满颗粒的界面的平衡细观结构的作用，表征成分对变形界面的流变性和细观结构的作用，并将成分的变化（例如颗粒表面浓度、颗粒尺寸和多分散性和表面活性剂浓度对颗粒间力和粘性力的影响。 这种界面的粘弹性会影响乳液的动力学行为，包括液滴变形、聚结和破碎。 了解成分和流变学之间的关系将使从业者能够定制界面并设计具有所需性能的材料。