CAREER: Yield Behavior of Particulate Aggregates and Gels

9876135米勒聚集颗粒的凝胶的屈服性质在陶瓷制造、化学加工和采矿工业中具有重要的经济意义，但仍然知之甚少。 由于缺乏直接研究颗粒聚集体和凝胶变形特性的实验技术，进展受到阻碍。 该学院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，以获得对颗粒在剪切和压缩过程中重新排列所需的机制，频率和力的定量了解。 将原位观察颗粒凝胶变形，以确定发生的不同重排模式及其频率。 微机械测试将直接测量颗粒重排所需的力。 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媲美。 实验将使用各种模型和技术相关的胶体进行，系统地改变粒径，颗粒体积分数和颗粒间的潜力。 预计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。 具体项目包括基于网络的三维晶体结构模型的材料类结构的实施，在陶瓷加工的研究生讲座/实验室类的发展，和新的课程评估技术的实施。 外联活动将侧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的例子。 该课程将以两种形式提供：一个讲座/讨论格式将在矿业的科罗拉多学校教授，和基于网络的远程学习格式。预计后者的努力将是特别有吸引力的教师在农村和贫困areas.The拟议的研究利用新开发的数字视频显微镜和微机械测试技术，定量研究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，在所有学生水平的教学，以及课程开发。外展活动的重点是开发和教学专业发展课程的高中科学教师。 使用可视化技术增进理解是贯穿拟议活动的一个主题。

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.