Ionic Transport in Ion Containing Copolymer-Grafted Nanoparticle Structures

从该项目中获得的基本理解将为设计下一代能源设备（如电池、燃料电池膜、超级电容器和电致动器）的新材料提供科学依据。该项目旨在通过在这些纳米颗粒上生长具有不对称成分的聚合物来合成聚合物功能化的球形磁性纳米颗粒，即“聚合物接枝纳米颗粒”。其分子结构的一个特殊特征是在聚合物链的末端存在含离子分子。这些功能性的、基于颗粒的纳米材料将被研究为固态电解质，可用于燃料电池电解质膜。该项目旨在了解“离子液体”（液态盐）中纳米颗粒结构与离子电导率之间的关系。所得到的纳米材料是具有离子传导网络结构的无泄漏、无蒸汽、不易燃的固体电解质。此外，它们还具有各种优点，如高机械稳定性，因为材料由无机颗粒组成；它们在聚合物链中的离子含量也很低，吸水性也很低。纳米材料的设计是为了控制离子聚集，研究纳米结构颗粒内离子液体的限制，增强离子迁移率，揭示离子传输机制。该项目将在能源应用材料的广泛领域对研究生和本科生以及学校教师进行培训。将为新泽西/纽约地区的高中科学教师组织一个纳米科学教育者研讨会，旨在帮助教师将纳米科学概念和应用整合到他们的课程中。本项目旨在探索基于纳米粒子的聚电解质中的离子传输。PI提出了一个全面的研究计划，以支持在离子液体中以低磺化量的聚甲基丙烯酸甲酯-苯乙烯磺酸链接枝的纳米颗粒的电导率的基本机制。假设离子聚集和离子团簇大小可以通过含离子的共聚物接枝纳米颗粒组织成串状、渗透和分散体系来控制。PI将使用准弹性中子散射实验研究合成的接枝纳米颗粒薄膜的片段链动力学和离子输运。测量的链和离子迁移率将与从x射线散射、透射电子显微镜和断层扫描获得的结构信息相结合。该项目的主要目标是了解聚（甲基丙烯酸甲酯）接枝氧化铁纳米颗粒在各种溶剂和离子液体中的组装；确定苯乙烯磺酸酯链端基对聚甲基丙烯酸甲酯接枝颗粒组装的影响，并测量其对链动力学和电导率的影响。该奖项反映了美国国家科学基金会的法定使命，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。

NON-TECHNICAL SUMMARYThe fundamental understanding gained from this project will provide the scientific basis for designing new materials for next-generation energy devices such as batteries, fuel-cell membranes, supercapacitors, and electroactive actuators. The project aims to synthesize polymer-functionalized spherical magnetic nanoparticles known as "polymer-grafted nanoparticles" by growing polymers with asymmetric composition onto these nanoparticles. A special feature of their molecular architecture is the presence of ion-containing molecules in the end of the polymer chains. These functional, particle-based nanomaterials will be studied as solid-state electrolytes, which can be used in fuel-cell electrolyte membranes. The PI aims to understand the relationship between nanoparticle structures in "ionic liquids" (which are salts in a liquid state) and ionic conductivity. The resulting nanomaterials are leak- and vapor-free and non-flammable solid electrolytes with ion-conducting network structures. Furthermore, they also hold various advantages such as high mechanical stability since the material is composed of inorganic particles; they also have low ionic content in the polymer chains and low water uptake. The nanomaterials are designed so as to control ion aggregation, enable study of confinement of ionic liquids within nanostructured particles, enhance ionic mobility, and unravel ion transport mechanisms. The project will train graduate and undergraduate students and schoolteachers in the broad area of materials for energy applications. A Nanoscience Educator Workshop will be organized for high-school science teachers in the New Jersey/New York area, aiming to help teachers to integrate nanoscale science concepts and applications into their courses.TECHNICAL SUMMARYThis project aims to explore ion transport in nanoparticle-based polyelectrolytes. The PI proposes a comprehensive research plan to underpin the fundamental mechanism of conductivity in the nanoparticles grafted with poly(methyl methacrylate-b-styrenesulfonate) chains with low sulfonation amounts in ionic liquids. It is hypothesized that ionic aggregation and ionic cluster sizes can be controlled by the organization of ion-containing copolymer-grafted nanoparticles into strings, percolated and dispersed systems. The PI will study segmental chain dynamics and ion transport of the synthesized grafted nanoparticle films using the quasi-elastic neutron scattering experiments. The measured chain and ion mobility will be combined with the structural information obtained from X-ray scattering, transmission electron microscopy, and tomography. The major objectives of the project are to understand the assembly of poly(methyl methacrylate)-grafted iron oxide nanoparticles in various solvents and ionic liquids under confinement; and to determine the effect of styrenesulfonate chain end groups on the assembly of poly(methyl methacrylate)-grafted particles and measure its impact on chain dynamics and conductivity.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.