BRIGE - Liquid-phase nanotechnology: Dispersion, rheology, and applications of pristine graphene

BRIGE - 液相纳米技术：原始石墨烯的分散、流变和应用

• 批准号: 1032330
• 负责人: Micah Green
• 金额: $ 17.47万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1032330&HistoricalAwards=false
• 关键词: BRIGE; Liquid; phase; nanotechnology; Dispersion

1032330GreenSingle-layer graphite, known as graphene, has taken center-stage as a revolutionary new nanomaterial in recent years due to its excellent mechanical, thermal, and electrical properties, including the capability for several unusual quantum effects. Graphene shows great promise as the basis for novel multifunctional materials, including field effect transistors, flexible electronics, transparent thin films, nanocomposite fillers, and structural carbon fiber. Many of these materials and devices require scalable, liquid-phase processing. However, development of such materials has been hampered by fundamental scientific challenges associated with each processing step (1) Difficult dispersion due to poor exfoliation and rapid re-aggregation of graphene sheets, (2) poor interfacial adhesion between filler and matrix, (3) poor understanding of bulk processing, particularly in regard to graphene rheology and microstructure. Prior studies have utilized chemically modified graphene with properties far inferior to pristine graphene. The goal of this program is to overcome these processing challenges for pristine graphene-based materials. We generate pristine graphene sheets encapsulated in a polymer nano-coating through localized polymerization on the graphene surface, as demonstrated through successful preliminary proof-of-principle experiments. This technique results in stabilization against aggregation and will be demonstrated by effective incorporation into polymer nanocomposites. We also create innovative studies in the novel field of graphene rheology in order to enable controlled graphene processing. We compare experimental rheometric results against simulations of the microstructure-rheology model for discotic solutions. Preliminary simulation results show promising results for modeling alignment dynamics.Intellectual merit: This transformative engineering plan meets three critical scientific challenges in the graphene community. Novel interfacial polymerization techniques are generated for (1) the production of re-dispersible, pristine graphene, which has never been attained before. Furthermore, polymer coating allows (2) the precise engineering of the interface between graphene and the polymer matrix in nanocomposites to increase interfacial strength. This approach is groundbreaking because it avoids the degraded properties associated with the commonly-used graphite oxide processing route. This program also pioneers the novel field of (3) graphene rheology and correlates rheological properties with graphene alignment and dispersion quality through a combination of experimental and computational studies.Broader impacts: Although this program focuses on the fundamentals of graphene dispersion, interfacial chemistry, and rheology, these findings have immediate application to the wide range of graphene-based materials and devices in need of bulk liquid-phase processing, including electronic devices, composites, and films. Thus, this interdisciplinary program combines fundamental scientific research with practical engineering applications. The findings will be disseminated on the broad scale through presentations and publications and on the local scale through the PI's functional materials course.Broadening Participation: The program seeks to integrate research and education by engaging undergraduate researchers and a high-school teacher with a central role in problem design and visualization for the simulation aspects of the work. In concert with these research efforts, the PI and the high school teacher will partner with the TTU T-STEM Center to create, evaluate, field-test, and disseminate nanotechnology curriculum for use in STEM education for grades 9-12. The curriculum uses both scientific and ethical challenges in nanotechnology as a platform for student-driven research projects and debates. This curriculum will emphasize student inquiry and active learning in order to provide deeper investigation and learning and generate increased interest in STEM fields among underrepresented groups. This curriculum creates new motivation and enthusiasm in STEM fields by emphasizing the potential for nanotechnology to be used for environmental responsibility and social justice (e.g., oil spill clean-up, water purification in developing countries); such topics are often neglected in STEM education and will engage a broader spectrum of student backgrounds.

1032330绿色单层石墨，被称为石墨烯，近年来已成为一种革命性的新型纳米材料，由于其优异的机械，热和电气性能，包括几种不寻常的量子效应的能力。石墨烯作为新型多功能材料的基础显示出巨大的前景，包括场效应晶体管、柔性电子产品、透明薄膜、纳米复合材料填料和结构碳纤维。这些材料和设备中的许多需要可扩展的液相处理。然而，这种材料的开发受到与每个加工步骤相关的基础科学挑战的阻碍，（1）由于石墨烯片的差的剥离和快速再聚集而难以分散，（2）填料和基质之间的差的界面粘附，（3）对本体加工的理解差，特别是关于石墨烯流变学和微观结构。 先前的研究已经利用化学改性的石墨烯，其性质远不如原始石墨烯。 该计划的目标是克服原始石墨烯基材料的这些加工挑战。我们通过在石墨烯表面上的局部聚合产生封装在聚合物纳米涂层中的原始石墨烯片，如通过成功的初步原理验证实验所示。这种技术导致稳定，防止聚集，并将通过有效地纳入到聚合物纳米复合材料证明。我们还在石墨烯流变学的新领域进行创新研究，以实现可控的石墨烯加工。 我们比较实验的流变学结果对模拟的微观结构流变模型dispersion解决方案。 初步的模拟结果显示出建模对齐动态的良好结果。智力价值：这一变革性的工程计划满足了石墨烯社区的三个关键科学挑战。产生了新的界面聚合技术，用于（1）生产以前从未实现过的可再分散的原始石墨烯。此外，聚合物涂层允许（2）纳米复合材料中石墨烯和聚合物基质之间的界面的精确工程化以增加界面强度。这种方法是开创性的，因为它避免了与常用的氧化石墨加工路线相关的性能下降。该项目还开拓了（3）石墨烯流变学的新领域，并通过实验和计算研究相结合，将流变学特性与石墨烯排列和分散质量相关联。虽然该计划侧重于石墨烯分散，界面化学和流变学的基本原理，这些发现可直接应用于需要本体液相处理的各种石墨烯基材料和器件，包括电子器件、复合材料和膜。因此，这个跨学科的计划将基础科学研究与实际工程应用相结合。调查结果将通过演讲和出版物在广泛的范围内传播，并通过PI的功能材料课程在地方范围内传播。扩大参与：该计划旨在通过参与本科研究人员和高中教师在问题设计和可视化方面发挥核心作用来整合研究和教育。与这些研究工作相一致，PI和高中教师将与TTU T-STEM中心合作，创建，评估，现场测试和传播纳米技术课程，用于9-12年级的STEM教育。该课程利用纳米技术的科学和伦理挑战作为学生驱动的研究项目和辩论的平台。该课程将强调学生的探究和主动学习，以提供更深入的调查和学习，并在代表性不足的群体中提高对STEM领域的兴趣。该课程通过强调纳米技术用于环境责任和社会正义的潜力，在STEM领域创造了新的动力和热情（例如，这些主题在STEM教育中往往被忽视，将涉及更广泛的学生背景。