Nanoparticle ionic fluids: interactions and transport properties

纳米粒子离子液体：相互作用和传输特性

• 批准号: 0756516
• 负责人: Lynden Archer
• 金额: $ 31.5万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0756516&HistoricalAwards=false
• 关键词: Nanoparticle; ionic; fluids; interactions; transport

CBET-0756516ArcherIntellectual Merit: Nanoparticle-based ionic materials (NIMS) are a new class of hybrid materials recently discovered at Cornell. NIMS are created by covalent attachment of charged oligomers to the surface of nanoparticles. The charge on the oligomer is balanced by a counterion species that can vary from a compact molecular entity such as a chloride ion, to a more bulky organic species such as an Isosterate ion. Depending on the interactions between the components (core particles, attached oligomers, and associated counterions), physical properties of the materials can be tuned over a surprisingly wide range. On one end of the spectrum are materials with high core particle content, which display properties similar to glasses, stiff waxes, and gels. At the opposite extreme are systems that spontaneously form homogeneous particle-based ionic fluids, characterized by transport properties remarkably similar to simple Newtonian liquids comprised of molecular building-blocks. These nanoparticle ionic fluids resemble molecular ionic liquids in their ability to form zero vapor pressure, ?green?, solvents with high dielectric constants. Because they contain an inorganic particle core, however, a more exciting array of properties can be accessed. The proposed research uses a combination of experiment, theory, and computer simulations to understand the fundamental forces in NIMS and to determine how these forces influence their transport properties. Our preliminary studies indicate that nanoparticle ionic fluids are the first example of a system of particles of any size that can reach equilibrium without a solvent. These studies also indicate that two new types of interactions are important for understanding the stability of our fluids and for predicting their transport properties: (i) An entropic attraction force arising from attachment of the effective solvent to the core particles; and (ii) Electrostatic forces due to surface-attached, bendable dipoles on the cores.Broader Impacts: The NIMS core particle is an inorganic nanostructure. This open possibility for creating entirely new types of hybrid fluids based upon the vast library of available inorganic particle chemistries and shapes. The unique properties possible in such fluids makes them attractive for a host of applications, including high-conductivity heat-transfer liquids, inkjet printable semiconducting inks, stable electrolytes for high-temperature batteries, light-weight conformal armor for military and law-enforcement personnel, and high refractive index liquids for photolithograph. Most of these applications are inaccessible to fluids created from molecular building blocks. The proposed research is the first attempt to develop fundamental understanding of the interaction forces that control structure and properties of these types of fluids. We believe that our work will provide crucial guidance on how to select components (e.g. core particle size, shape, volume fraction, corona and counterion molecular weight, and chemistry), for the many applications targeted. Furthermore, because our fluids combine elements of colloids, polymers, and complex-fluid behavior in a single material, we believe that results from the proposed research will help expand and modernize the literature on colloidal phenomena and complex fluid flows. We believe a direct result of the range of applications that will be impacted by our materials, is that transfer of knowledge developed in the study to the classroom will be more rapid than normal for subjects in the field. The novelty of NIMS and their relevance to easily appreciated applications also provides new opportunities for attracting younger students (K-12) to science. Specifically, in collaboration with the Cornell Center for Materials Research (CCMR), we will develop demonstrations based on applications of the materials, e.g. as inkjet printable inks, conformal body armor, and high-index liquids for photolithography. Our goals for these demonstrations are to engage students at an early age to think about materials in terms of their fundamental units or building blocks, and to recognize the connection between physical properties and the forces between these units. We also believe that video demonstrations connecting flow transitions in NIMS to structural transitions revealed by scattering experiments will help advanced students appreciate relationships between transport properties of complex fluids and their interactions. We will use these video demonstrations in our undergraduate Fluid Mechanics (ChemE 323) and graduate Polymer Physics (ChemE 745) courses, and also plan to take advantage of the YouTube web portal to disseminate them to a broader audience.

CBET-0756516 ArcherIntlectual功绩：基于纳米颗粒的离子材料（NIMS）是最近在康奈尔（Cornell）发现的新型混合材料。 NIM是通过将带电的低聚物的共价附着在纳米颗粒表面上的共价附着而产生的。寡聚物上的电荷是由一种可以从紧凑的分子实体（例如氯离子）到更笨重的有机物种（例如等骨离子）的抗合成分平衡的。根据组件之间的相互作用（核心颗粒，附着的低聚物和相关的柜台），可以在令人惊讶的宽范围内调整材料的物理特性。频谱的一端是具有高核心颗粒含量的材料，它们的特性类似于玻璃，硬蜡和凝胶。 在相反的极端是自发形成均匀基于粒子的离子流体的系统，其特征在于运输特性与由分子建筑块组成的简单牛顿液体非常相似。这些纳米颗粒离子流体类似于分子离子液体，它们具有零蒸气压的能力，具有高介电常数的溶剂。但是，由于它们包含无机粒子芯，因此可以访问更令人兴奋的属性。拟议的研究结合了实验，理论和计算机模拟的组合来了解NIMS中的基本力，并确定这些力如何影响其运输特性。我们的初步研究表明，纳米颗粒离子流体是可以在没有溶剂的情况下达到平衡的任何大小颗粒系统的第一个例子。这些研究还表明，两种新类型的相互作用对于理解流体的稳定性和预测其运输特性很重要：（i）由有效溶剂附着在核心颗粒上引起的熵吸引力； （ii）由于核心上的表面连接，可弯曲的偶极子引起的静电力。BOODER的影响：NIMS核心粒子是一种无机纳米结构。这种开放的可能性是基于可用的无机颗粒化学和形状的庞大库来创建全新类型的混合流体。这种流体中可能的独特特性使它们对许多应用具有吸引力，包括高导度热转移液体，可打印的可打印的半导体油墨，用于高温电池的稳定电解质，用于军事和法律用力人员的轻重量结合盔甲，以及高折射式Index Index液体的光学量。这些应用中的大多数是通过分子构建块产生的流体无法访问的。拟议的研究是对控制这些类型流体的结构和特性的相互作用的基本理解的首次尝试。我们认为，我们的工作将提供有关如何针对许多针对的应用程序选择组件（例如核心粒度，形状，体积分数，电晕和反式分子量以及化学）的关键指导。此外，由于我们的流体结合了单个材料中胶体，聚合物和复杂流体行为的元素，因此我们认为，拟议的研究的结果将有助于扩展和现代化有关胶体现象和复杂流体流的文献。我们认为，将会受到我们材料影响的一系列应用的直接结果，是在研究中开发的知识转移到课堂上的知识将比现场受试者的正常速度快。 NIMS的新颖性及其与易于欣赏的应用的相关性也为吸引年轻学生（K-12）加入科学提供了新的机会。具体而言，与康奈尔材料研究中心（CCMR）合作，我们将根据材料的应用来开发示范，例如作为可打印油墨，保形的身体装甲和高索引液体的，用于光刻。这些示威活动的目标是让学生在很小的时候与他们的基本单位或构建块一起思考材料，并认识到物理属性与这些单位之间的力量之间的联系。我们还认为，通过散射实验揭示的NIM中流动过渡与结构过渡的视频演示将有助于高级学生欣赏复杂流体的运输属性与其相互作用之间的关系。我们将在本科生机械师（Cheme 323）和研究生聚合物物理学（Cheme 745）课程中使用这些视频演示，并计划利用YouTube Web门户网站将它们传播给更广泛的受众。