CAREER: Understanding Electrostatic Interactions in Non-Polar Media for Generation of Nanostructured Thin Films

技术概述：该奖项由固态与材料化学（SSMC）计划和国际科学与工程办公室（OISE）共同资助，旨在通过研究非极性介质中静电相互作用的基础，了解最近开发的非水层逐层（LbL）纳米结构薄膜组装。这项工作将在单粒子水平上对相反电荷材料之间静电相互作用的基础研究与基于单个纳米粒子的电荷特性预测纳米结构LbL薄膜的组成和结构联系起来。我们将利用原子力显微镜研究非极性介质中单粒子水平静电相互作用的性质和意义，这也将揭示在小间距下，相反带电粒子的表面电位和电荷是如何变化的。利用等温滴定量热法还将研究极性溶液中极性材料的LbL组装的热力学性质，以揭示纳米颗粒组装是熵驱动还是焓驱动的过程。从这些研究中获得的知识将被结合并转化为定量预测和理解基于单个纳米颗粒电荷特性的LbL薄膜的组成和结构。非技术概述：纳米结构薄膜是由多种材料（如纳米颗粒和聚合物）组成的薄层，具有独特的特性组合，使其在能量转换和存储等高级应用中非常有用。层接层组装（LbL）涉及到相反带电物质的顺序沉积，为生成功能纳米结构薄膜提供了一种简单而通用的方法；然而，到目前为止，这项技术主要用于水溶性材料。这种做法给产生用于替代能源应用的功能性纳米结构薄膜带来了主要障碍，因为大量有用和独特的纳米材料只能在非水非极性溶剂中合成和稳定。PI最近成功地在非极性介质中赋予各种纳米材料表面电荷，并基于LbL组装制备了功能纳米结构薄膜。这个职业奖的目的是了解非极性溶剂中静电相互作用的基本方面，这将进一步扩展新的LbL技术在替代能源中的应用。该奖项还将教育活动整合到研究计划中，目的是充分利用逐层组装的视觉和实践方面，丰富大学预科学生和教育工作者的教育经验。少数族裔和女大学生将参加蔚山国立科学技术院的“海外研究”项目，这将为她们提供扩大世界视野和培养科学交流能力的机会。

TECHNICAL SUMMARY: The objective of this CAREER award, co-funded by the Solid State and Materials Chemistry (SSMC) program and the Office of International Science and Engineering (OISE), is to understand a recently developed non-aqueous layer-by-layer (LbL) assembly of nanostructured thin films by studying the fundamentals of electrostatic interactions in non-polar media. This work bridges the fundamental investigation of electrostatic interactions between oppositely charged materials at the single particle level to the prediction of the composition and structure of nanostructured LbL thin films based on the charge characteristics of individual nanoparticles. The nature and significance of electrostatic interactions in non-polar media at the single particle level will be studied using atomic force microscopy, which will also reveal how the surface potential and charge of oppositely charged particles change at small separations. The thermodynamic nature of LbL assembly of oppositely charged materials in apolar solutions will also be investigated using isothermal titration calorimetry to uncover whether the nanoparticle assembly is an entropically or enthalpically driven process. Knowledge from these studies will be combined and translated to quantitatively predict and understand the composition and structure of LbL thin films based on the charge characteristics of individual nanoparticles. NON-TECHNICAL SUMMARY: Nanostructured thin films are thin layers composed of multiple materials such as nanoparticles and polymers, and possess distinctive combinations of properties that make them useful for advanced applications such as energy conversion and storage. Layer-by-layer (LbL) assembly, which involves the sequential deposition of oppositely charged species, provides a simple yet versatile method for the generation of functional nanostructured thin films; however, this technique, to date, has been primarily used with water-soluble materials. This practice places a major obstacle to generating functional nanostructured thin films for alternative energy applications, because a large number of useful and unique nanomaterials are synthesized and stable in non-aqueous non-polar solvents only. The PI has recently successfully imparted surface charge to various nanomaterials in non-polar media and fabricated functional nanostructured thin films based on LbL assembly. The aim of this CAREER award is to understand the fundamental aspects of electrostatic interactions in non-polar solvents, which will further extend the new LbL technique for alternative energy applications. This CAREER award also integrates educational activities into the research plan with the goal of fully utilizing visual and hands-on aspects of layer-by-layer assembly to enrich the educational experiences of pre-college students and educators. Under-represented minority and female undergraduate students will participate in "Research Abroad" program at the Ulsan National Institute of Science and Technology in Korea, which will provide them with opportunities to broaden their view of the world and develop scientific communication skills.