Research Initiation Award Grant - Colloidal Mixtures: Microstructure and Mechanics

研究启动奖 - 胶体混合物：微观结构和力学

• 批准号: 1238524
• 负责人: Subramanian Ramakrishnan
• 金额: $ 19.99万
• 依托单位: Florida Agricultural and Mechanical University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1238524&HistoricalAwards=false
• 关键词: Research; Initiation; Award; Grant; Colloidal

The Research Initiation Award entitled - Colloidal Mixtures: Microstructure and Mechanics - investigates mixtures of colloidal particles which are used in a wide array of commercial and industrial products. In many applications, the colloidal suspensions transform between fluid and disordered solid states when parameters such as the colloidal volume fraction and the strength and nature of the colloidal interactions are varied. Understanding the connection between the microscopic and macroscopic properties remains a central challenge for the field of colloid science. X-ray photon correlation spectroscopy (XPCS) has emerged as a technique uniquely suited for revealing the salient nanometer-scale structural dynamics in glassy colloidal suspensions. This project combines XPCS with rheometry in new ways to make direct connections between the microscopic dynamics and rheology of mixtures of nanocolloidal suspensions.The project will consist of four stages: 1) By investigating the consequences of a bimodal size distribution combined with intrinsic short-range attractions between colloids, the experiments will open a new avenue for controlling suspension phase behavior and rheology. 2) The experimental characterization of the microstructure, dynamics and mechanical response in these colloidal materials will provide a series of benchmarks for rigorous testing of different theories. 3) The developed theory of predicting the flow properties from measured microstructures will result in a microscopic understanding of the rheological properties. Coupled with the knowledge of how experimentally controlled variables affect these microscopic parameters opens up avenues for controlling the flow properties of dense suspensions and gels. 4) Techniques will be developed at Argonne National Laboratory to study the dynamics of colloidal gels and this will be extremely useful in studying the dynamics of a variety of soft condensed matter systems and will be of interest to a number of other users at ANL. The project is expected to lead to a fundamental and microscopic understanding of dynamics of condensed matter systems and to revolutionize processing of such systems by control of their rheology and flow properties.

该研究启动奖题为-胶体混合物：微观结构和力学-研究胶体颗粒的混合物，用于广泛的商业和工业产品。在许多应用中，当参数如胶体体积分数和胶体相互作用的强度和性质变化时，胶体悬浮液在流体和无序固体状态之间转变。 理解微观和宏观性质之间的联系仍然是胶体科学领域的核心挑战。 X射线光子相关光谱（XPCS）已成为一种独特的技术，适合于揭示显着的纳米尺度的结构动力学在玻璃胶体悬浮液。该项目将XPCS与流变学以新的方式相结合，将纳米胶体悬浮液的微观动力学和流变学直接联系起来，该项目将包括四个阶段：1）通过研究双峰尺寸分布与胶体之间固有的短程吸引力相结合的结果，实验将为控制悬浮液相行为和流变学开辟新的途径。 2)这些胶体材料的微观结构、动力学和力学响应的实验表征将为不同理论的严格测试提供一系列基准。3)从测量的微观结构预测的流动性能的发展理论将导致流变性能的微观理解。再加上实验控制变量如何影响这些微观参数的知识，开辟了控制致密悬浮液和凝胶的流动特性的途径。4)技术将开发在阿贡国家实验室研究胶体凝胶的动力学，这将是非常有用的研究各种软凝聚态系统的动力学，并将感兴趣的一些其他用户在ANL。该项目预计将导致凝聚态系统的动力学的基本和微观的理解，并通过控制其流变学和流动特性来彻底改变这种系统的处理。