CAREER: Yield Behavior of Particulate Aggregates and Gels

职业：颗粒聚集体和凝胶的屈服行为

• 批准号: 9876135
• 负责人: Kelly Miller
• 金额: $ 28.27万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9876135&HistoricalAwards=false
• 关键词: CAREER; Yield; Behavior; Particulate; Aggregates

9876135MillerThe yield properties of gels of aggregated particles are of great economic significance in the ceramics manufacturing, chemical processing, and mining industries, yet remain very poorly understood. Progress has been hampered by the lack of experimental techniques to directly examine the deformation properties of particle aggregates and gels. This Faculty Early CAREER Development project utilizes newly developed digital video microscopy and micromechanical testing techniques to gain a quantitative understanding of the mechanisms, frequencies, and forces required for particles to rearrange during shear and compression. Particulate gel deformation will be observed in-situ to determine the different rearrangement modes which occur, as well as their frequency. Micromechanical testing will directly measure the forces required for particle rearrangement. The micromechanical testing methods have great potential in the study of colloids - with further development, these methods may be able to rival the force resolution of colloidal probe atomic force microscopy. The experiments will be conducted using a variety of model and technically relevant colloids, systematically varying particle size, particle volume fraction, and interparticle potential. It is anticipated that this work will serve as the experimental basis needed to guide the theoretical modeling of particulate gel rheological behavior. Continuing development of undergraduate and graduate level courses will be a major educational goal. Specific projects include the implementation of web-based three dimensional crystal structure models for a structure of materials class, development of a graduate lecture/-laboratory class in ceramics processing, and implementation of new course assessment techniques. Outreach activities will focus upon development of a professional enhancement course for high school science teachers, emphasizing the use of examples from materials science and engineering in standards-based education. The course will be offered in two forms: a lecture/-discussion format to be taught at the Colorado School of Mines, and a web-based distance learning format. It is anticipated that the latter effort will be especially attractive to teachers in rural and disadvantaged areas.The proposed research utilizes new developed digital video microscopy and micromechanical testing techniques to quantitatively examine the deformation modes of particulate gels. The educational component of the plan includes mentoring of freshmen and undergraduate researchers, teaching at all student levels, and course development. The outreach activities are focused upon developing and teaching professional development courses for high school science teachers. The use of visualization techniques to enhance understanding is a theme running throughout the proposed activities.

9876135 Miller凝胶的凝胶的产量特性在陶瓷制造，化学加工和采矿行业中具有很高的经济意义，但仍然非常了解。 缺乏直接检查颗粒聚集体和凝胶的变形特性的实验技术阻碍了进步。 该教师早期职业发展项目利用新开发的数字视频显微镜和微机械测试技术来获得对剪切和压缩过程中颗粒所需的机制，频率和力量的定量理解。 将观察到颗粒凝胶变形，以确定发生的不同重排模式以及它们的频率。 微电机械测试将直接测量粒子重排所需的力。 微机械测试方法在胶体的研究中具有巨大的潜力 - 随着进一步的发展，这些方法可能能够与胶体探针原子力显微镜的力分辨率相抗衡。 实验将使用多种模型和技术相关的胶体，系统变化的粒径，粒子体积分数和颗粒间电位进行。 可以预料，这项工作将作为指导颗粒凝胶流变行为的理论建模所需的实验基础。 继续发展本科和研究生课程将是一个主要的教育目标。 特定项目包括实施基于Web的材料类结构的三维晶体结构模型，开发陶瓷处理中的研究生讲座/实验室类别以及实施新的课程评估技术。 外展活动将着重于为高中科学教师开发专业增强课程，强调在基于标准的教育中使用材料科学和工程学的示例。 该课程将以两种形式提供：在科罗拉多州矿业学院教授的讲座/ - 讨论格式，以及基于网络的远程学习格式。预计后者的努力将对农村和处境不利的地区的教师特别有吸引力。拟议的研究利用了新的开发的数字视频显微镜和微机械测试技术来定量检查颗粒凝胶的变形模式。 该计划的教育部分包括指导新生和本科研究人员，在所有学生级别的教学以及课程发展。外展活动的重点是为高中科学教师开发和教授专业发展课程。 使用可视化技术来增强理解是在整个提出的活动中运行的主题。