CAREER: Interactions between 2D particles at fluid-fluid interfaces

职业：流体-流体界面处二维粒子之间的相互作用

• 批准号: 1944725
• 负责人: Joseph Samaniuk
• 金额: $ 53.4万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1944725&HistoricalAwards=false
• 关键词: CAREER; Interactions; between; 2D; particles

Two-dimensional (2D) materials have properties that are unique because they are atomically thin. Properties such as electrical conductivity, mechanical strength, and optical transparency can be significantly enhanced in these materials compared with their “bulk” material counterparts. There is a growing list of 2D materials, the most common examples being graphene, molybdenum disulfide (MoS2), and hexagonal boron-nitride (h-BN). These materials and others are used in a wide range of consumer products including electronic devices and composite materials. One of the challenges of utilizing 2D materials is their fabrication, which is often accomplished by assembling a collection of 2D particles at the microscopic scale to create a larger material with the desired properties. This project will help understand how 2D particles interact with each other when confined to a fluid-fluid interface, a type of confinement that can be used to assemble 2D particles “edge-to-edge”. The project will also develop techniques for fabricating model 2D particles of controlled size and shape, which will advance the experimental work needed to understand these systems. Results from the project will provide fundamental insight about the interactions of 2D particles that scientists and engineers can use to process 2D particles into advanced films, coatings, and composites. In addition, the project team will work with the Summer Multicultural Engineering Training Program (SUMMET) at the Colorado School of Mines to introduce high school seniors to opportunities in undergraduate research. The goal is to increase awareness of undergraduate research as an opportunity available to these traditionally underrepresented students in science and engineering, and ultimately to encourage their participation in science, technology, engineering, and mathematics (STEM) fields.The interaction potential between 2D particles of controlled size, shape, and thickness at air-water interfaces will be measured from direct observation of particle trajectories and particle assemblies. The model 2D particles will be fabricated in-house using photolithography to selectively pattern 2D material films grown via chemical vapor deposition on copper foil. The foil will be placed at the fluid-fluid interface and removed with etchant solution in a sub-phase exchange cell, and the remaining particles will be visualized with interference reflection microscopy. Contact line undulations around particles will be probed with various forms of gel trapping in conjunction with electron microscopy to understand the nature of capillary forces on the particle-particle interactions. The influence of particle-particle interactions on the macroscopic film structure and strength will be investigated with interfacial rheological tools. The overall goal of the project is to understand the nature of the interactions between 2D particles confined to a fluid-fluid interface, and in particular how the low-dimensional morphology of 2D particles plays a role.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.

二维（2D）材料具有独特的性质，因为它们是原子级薄的。这些材料的导电性、机械强度和光学透明度等性能与其“块状”材料相比可以显著增强。有越来越多的2D材料，最常见的例子是石墨烯，二硫化钼（MoS 2）和六方氮化硼（h-BN）。这些材料和其他材料用于广泛的消费产品，包括电子设备和复合材料。利用2D材料的挑战之一是它们的制造，这通常是通过在微观尺度上组装2D颗粒的集合来实现的，以创建具有所需特性的较大材料。这个项目将有助于了解当被限制在流体-流体界面时，2D粒子如何相互作用，这是一种可用于组装2D粒子“边缘到边缘”的限制类型。该项目还将开发制造尺寸和形状可控的2D模型颗粒的技术，这将推进理解这些系统所需的实验工作。该项目的结果将提供有关2D颗粒相互作用的基本见解，科学家和工程师可以利用这些见解将2D颗粒加工成先进的薄膜、涂层和复合材料。此外，该项目小组将与夏季多元文化工程培训计划（SUMMET）在科罗拉多矿业学院介绍高中毕业生在本科研究的机会。我们的目标是提高对本科生研究的认识，将其作为这些传统上代表性不足的科学和工程专业学生的机会，并最终鼓励他们参与科学，技术，工程和数学（STEM）领域。空气-水界面处的厚度将通过直接观察颗粒轨迹和颗粒集合来测量。模型2D颗粒将使用光刻法在内部制造，以选择性地图案化通过化学气相沉积在铜箔上生长的2D材料膜。将箔放置在流体-流体界面处，并在亚相交换池中用蚀刻剂溶液去除，并用干涉反射显微镜观察剩余颗粒。将用各种形式的凝胶捕获结合电子显微镜来探测颗粒周围的接触线波动，以了解颗粒-颗粒相互作用上的毛细作用力的性质。粒子间的相互作用对宏观膜结构和强度的影响将与界面流变学工具进行研究。该项目的总体目标是了解受限于流体-流体界面的二维粒子之间的相互作用的性质，特别是二维粒子的低维形态如何发挥作用。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。