ISS: Kinetics of nanoparticle self-assembly in directing fields

首先，Eric m .通过组装胶体颗粒制造的先进材料的数量正在增长。在装配过程中，可以通过施加影响粒子运动及其排列的外场来控制装配。该项目将利用国际空间站（ISS）上的设备来研究在切换磁场存在下椭球形磁性粒子的组装。悬浮微粒聚集时的微观结构将通过光学显微镜来表征。粒子组合的力学性能，特别是屈曲不稳定性，也将被表征。国际空间站的微重力环境对这些实验很重要，因为粒子会在重力作用下沉积，随着它们形成大型复杂的结构，沉积速率会增加。该项目将为学生提供参与研究的机会，包括参加特拉华大学夏季青年工程师营和探索工程营的K-12学生。本科生将通过大学的本科生研究计划被招募到这个项目中。本项目的国际空间站实验将使用InSPACE硬件和微重力科学手套箱进行。实验将采用长宽比为2:1至4:1的磁性长椭球体进行。为了比较，还将进行涉及球体的实验。粒子的取向将由使用交叉偏振器的双折射测量来确定。研究了粒子形状、各向异性和磁场开关频率对粒子相分离的影响。持续时间相对较短，地面实验将使用相同的磁性粒子进行，以提供从粒子水平到中尺度结构形成的额外细节。本项目研究的胶体椭球体可以作为控制声热传播的声子带隙材料、超低导热涂层和具有丰富结构颜色的光子晶体的基石。研究小组将利用这个项目，通过为各种媒体，特别是那些专注于空间研究的媒体制作片段，来吸引公众。

CBET - 1637991PI: Furst, Eric M.The number of advanced materials manufactured by assembling colloidal particles is growing. The assembly can be controlled by applying external fields that affect the motion of the particles and their arrangement during assembly. This project will use facilities on board the International Space Station (ISS) to study the assembly of ellipsoidal magnetic particles in the presence of a toggled magnetic field. The microstructure of the suspension as the particles assemble will be characterized by light microscopy. Mechanical properties of the particle assemblies, especially buckling instabilities, will also be characterized. The microgravity environment of the ISS is important for these experiments, because the particles would sediment due to gravity with a sedimentation rate that increases as the they form large and complicated structures. The project will provide opportunities for students to participate in research, including K-12 students who participate in the University of Delaware's summer Young Engineers Camp and Exploring Engineering Camp. Undergraduates will be recruited to the project through the university's Undergraduate Research Program. The ISS experiments in this project will be conducted using InSPACE hardware and microgravity sciences glovebox. Experiments will be performed with magnetic prolate ellipsoids with aspect ratios ranging from 2:1 to 4:1. Experiments involving spheres will also be conducted for comparison purposes. The particle orientation will be determined from birefringence measurements using crossed polarizers. The effects of particle shape, anisotropy, and magnetic field toggling frequency on the phase separation of particles will be examined. Relatively short duration, ground-based experiments will be conducted using the same magnetic particles to provide additional details about structure formation from particle-level to mesoscale structure. The colloidal ellipsoids examined in this project could serve as building blocks for phononic bandgap materials that control the propagation of sound and heat, ultra-low thermal conductivity coatings, and photonic crystals with rich structural color. The research team will use the project to engage the public by producing segments for a variety of media outlets, especially those that concentrate on space-based research.