Directed Assembly by Capillarity

毛细管作用定向组装

• 批准号: 1066284
• 负责人: Kathleen Stebe
• 金额: $ 31.54万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1066284&HistoricalAwards=false
• 关键词: Directed; Assembly; Capillarity

Award: 1066284PI: StebeWe will perform fundamental studies to establish quantitative guiding principles for anisotropic capillary assembly, i.e. to relate particle shape, contact angle, and interface shape, to the range and strength of interactions and to the assemblies which form. To do so, we will study capillary assembly in experiment, numerics and theory. We have established an intellectual basis to study interactions between any anisotropic particles at interfaces which we are in the process of applying to cylindrically shaped particles with uniform contact angle. We choose cylinders as the first shape to study because they have intriguing properties when they are at interfaces- they have high interfacial area density near their planar end faces which cements end-to-end assembly. We now understand far field interactions between cylindrical particles at interfaces in detail. However, when the particles come close together, the strong deformations near the ends overlap, forming a strong interaction between particles termed a "capillary bond", whose strength we will quantify numerically. We will then check the validity of the calculation experimentally- this will establish the pair interactions between cylinders at interfaces at all separations. We will then address three assembly aims, selected to pave the way to fields which exploit oriented particle assemblies. We will: I. Establish in experiment whether, as scaling suggests, capillary interactions are important for sub-micron to nanoscale particles, important for making annealable structures and for extending the technological impact of capillary assembly. II. Characterize the strength of capillary assemblies using magnetic tweezers, important in applications that exploit particle-stabilized emulsions, colloidosomes, and other hierarchical assemblies. III. Develop capillary recognition elements, which would preferentially assemble only with mating particles like puzzle pieces on an interface. This requires that we develop and understand capillary repulsion to impart selectivity to particle interactions. These aims were selected to seed new materials-related research to exploit anisotropic particle assemblies. For example, ordered oriented particle monolayers could be exploited to epitaxially grow new 3-D structures; oriented, assembled anisotropic particles could allow new classes of metamaterials to be developed; capillary recognition elements could promote registry of particles with other features within devices, and could serve as sensors or read outs.

奖项：1066284PI：Stebewe将进行基本研究，以建立各向异性毛细管组件的定量指南原理，即将粒子形状，接触角和界面形状与相互作用的范围和强度以及形式的组件相关联。为此，我们将研究实验，数字和理论中的毛细管组装。我们已经建立了一个智力基础，以研究在界面处的任何各向异性颗粒之间的相互作用，我们正在应用于具有均匀接触角的圆柱形颗粒。我们选择圆柱作为第一个研究的形状，因为它们在界面时具有吸引人的特性 - 它们在平面端面附近具有较高的界面面积密度，这些面孔的面孔将端到端组装束缚。现在，我们了解详细界面处的圆柱粒子之间的远场相互作用。但是，当粒子靠近时，末端附近的强变形重叠，形成称为“毛细血管键”的粒子之间的强相互作用，我们的强度我们将用数值进行量化。 然后，我们将在实验上检查计算的有效性 - 这将在所有分隔处建立圆柱体之间的圆柱之间的对相互作用。然后，我们将解决三个组件的目的，以铺平利用方向粒子组件的字段铺平道路。我们将：I。在实验中建立，正如缩放表明的那样，毛细管相互作用对于对纳米级颗粒的亚微米很重要，对于制造退火结构和扩展毛细管组装的技术影响很重要。 ii。使用磁性镊子表征毛细管组件的强度，这在利用颗粒稳定的乳液，胶体体和其他分层组件的应用中很重要。 iii。开发毛细血管识别元素，该元素优先与界面上的拼图片（例如拼图零件）组装在一起。这要求我们发展和理解毛细血管排斥以赋予颗粒相互作用的选择性。这些目标选择与新材料相关的研究播种以利用各向异性颗粒组件。例如，可以将有序的定向粒子单层利用为外延生长新的3-D结构。面向，组装的各向异性颗粒可以允许开发新的超材料。毛细管识别元素可以促进设备内具有其他功能的粒子注册表，并且可以作为传感器或读取。