Excellence in Research - Collaborative: Hierarchical multilayered block copolymer dielectrics with z-gradient nanofiller for capacitive energy storage and gate dielectric

该项目由传统黑人学院和大学本科项目-卓越研究项目（HBCU-UP EiR）资助。非技术总结：人们对轻质聚合物薄膜在便携式能量存储设备（包括电池、电容器、集成太阳能电池和软致动装置）相关的柔性电子产品中的潜在应用非常感兴趣。在这方面，高能量密度电容储能的新方法最近显示出使用多层聚合物薄膜进行高电能存储的显著潜力。从本质上讲，多层内的多个界面依次阻止介电聚合物薄膜的电击穿，这决定了柔性电容器的能量存储上限。认识到击穿遵循电极之间越来越多的分支不对称路径（很像闪电击中地球），正极电位最高，该工作将系统地设计和探索混合聚合物多层（四层）是否可以在结构上“逆向工程”聚合物层击穿特性的不对称性，以对抗不对称击穿路径。该方法旨在使用自组装嵌段共聚物形成多层，并将其与分散无机纳米填料的使用相结合，以提高储能能力。成功的结果会对柔性电子行业产生重大影响。这个多学科团队的努力包括霍华德大学、杰克逊州立大学（历史上的黑人学院大学）和休斯顿大学（少数民族服务机构），以及大量的机构内和机构间教育、培训和研究活动。该项目将在每个校区每年轮流安排一次为期一天的纳米复合材料会议，让科学家、当地教师和当地大学生了解纳米技术的巨大可能性。将培训一批训练有素的有才华的纳米技术专家，以解决国家劳动力需求的挑战，并出版同行评议的科技出版物，这些出版物可以传播给科学界和更广泛的社会。该项目旨在为纳米科学和纳米工程领域的潜在研究人员提供可在网上访问的培训协议。技术总结;在固态柔性电容器中，高能量密度和超快充放电速率（脉冲功率）是至关重要的。能量存储密度受能施加在电极上的最大电场的限制。由于聚合物具有高电阻、低介电损耗、自愈能力、可成形性和灵活性，目前的脉冲功率应用技术利用聚合物作为首选电介质。然而，这些材料不能满足用于高压和高能量密度电子器件的下一代薄膜电介质的所有要求。计划中的工作是基于一种假设，即分子组装电容元素层的反对称z结构四层设计可以精确地抵消从正极到负极的电树击穿级联的不对称性。反对称薄膜结构考虑了一个具有极高防击穿能力的四层自组装多层嵌段共聚物，在正极处，根据电树击穿观点，电场强度最高。下一层也是嵌段共聚物结构，具有平面内对齐的纳米片，以防止电场级联击穿。第三层被设计为包含隔离在宏观有序嵌段共聚物层中的高介电纳米粒子，这也为2D半导体器件（如场效应晶体管）和逻辑设计提供了一种栅极介电策略，与传统介电材料相比，具有增强的功能。最后，使用无缺陷的底部聚合物层，这将防止滴流到负极。一个由霍华德大学和杰克逊州立大学（历史上的黑人大学）以及休斯顿大学（少数族裔服务机构）组成的多学科团队将致力于培养一批有才华的纳米技术专家，以应对国家劳动力需求的挑战。将为年轻和感兴趣的研究人员和公众提供纳米科学和纳米工程研究的网络模块。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。

This project is funded by the Historically Black Colleges and Universities Undergraduate Program - Excellence in Research program (HBCU-UP EiR). NON-TECHNICAL SUMMARY:There is much interest in use of lightweight polymer films for potential applications in flexible electronics related to portable energy storage devices, including batteries, capacitors, integrated solar cells and soft-actuation. In this regard, new approaches to high-energy density capacitive energy storage have recently demonstrated notable potential for high electrical energy storage using multilayered polymer films. Essentially the multiple interfaces within the multilayer act to sequentially block electrical breakdown of the dielectric polymer film that determines the upper limit of energy storage of the flexible capacitor. Recognizing that the breakdown follows an increasingly branched asymmetric pathway between electrodes (much like lightning bolts striking the earth), with the highest potential at the positive electrode, the work will systematically design and explore whether hybrid polymer multilayers (tetra-layered) can be structurally "reversed-engineered" with an asymmetry in polymer-layer breakdown properties that counters the asymmetric breakdown pathway. The approach aims to use self-assembling block copolymers for multilayer formation and combines it with the use of dispersed inorganic nanofillers to boost the energy storage capacity. Successful outcome can have a significant impact on the flexible electronics industry. This multidisciplinary team effort involves Howard University and Jackson State University (Historically Black College Universities) and University of Houston, a Minority Serving Institution, with significant amounts of intra and inter-institutional educational, training and research activities. The project will arrange a yearly rotational day-long conference on nanocomposites at each of the campuses to educate scientists, local teachers and local college bound students about the vast possibilities of nanotechnology. A trained cadre of talented nanotechnologists will be trained to address the challenges of the nation's workforce needs and produce peer reviewed scientific and technological publications that can be disseminated to the scientific community and broader society. The program aims to make web-accessible training protocols to prospective researchers in the field of nanoscience and nanoengineering.TECHNICAL SUMMARY;Fundamentally high energy densities and ultrafast charge-discharge rates (pulsed power) in solid state-flexible capacitors are of fundamental importance. The energy storage density is limited by the maximum electric field that can be applied across the electrodes. Current technologies for pulsed power applications utilize polymers as the dielectric of choice due to their high electrical resistance, low dielectric loss, self healing capability, formability and flexibility. However, these materials do not meet all of the requirements of the next-generation film dielectrics for high voltage and high energy density electronic devices. The planned work is based on the hypothesis that an anti-symmetric z-structured tetra-layered design of molecularly assembled capacitive elemental layers can precisely counter the asymmetry of the electrical treeing breakdown cascade from the positive to the negative electrode. The anti-symmetric film structure considers a tetra-layer with an extremely high breakdown prevention self-assembling multilayered block copolymer at the positive electrode where E-field strength is highest as per electrical treeing breakdown view-point. The subsequent layer is also a block copolymer structure with in-plane aligned nanosheets to forestall E-field cascade breakdown. The third layer is designed to contain high dielectric nanoparticles sequestered within a macroscopically ordered block copolymer layer, which also provides a strategy of gate dielectric for 2D semiconductor devices such as field-effect transistors and logic design with enhanced functionalities compared to the conventional dielectrics. Finally, a defect-free bottom polymer layer is used, which will prevent trickle-current to the negative electrode. A multidisciplinary team between Howard University and Jackson State University (Historically Black College Universities), and University of Houston, a Minority Serving Institution, will work towards training a cadre of talented nanotechnologists to face the challenges of the nation's workforce needs. Web modules on nanoscience and nanoengineering research for young and interested researchers and the general public will be made available.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.