CAREER: Manufacturing of Continuous Network Graphene-Copper Composites for Ultrahigh Electrical Conductivity

这项学院早期职业发展(CALEAR)补助金支持为制造超高导电性材料的新制造技术奠定基础的研究。这项研究利用了石墨烯在纯铜基质中的优异导电性，石墨烯是一种新兴的二维(2D)碳纳米材料。将进行基础的多尺度和多物理研究，以了解石墨烯-铜复合材料的制备和性能，这对实现高导电性材料的科学和技术进步至关重要。超高导电性材料的可获得性满足了电动汽车、便携式设备和电网中对高性能导电体日益增长的需求，这影响了各个行业，从而影响了美国经济。将开发新的实验方法来控制铜基中石墨烯网络的连续性，以获得明显高于纯铜的电导率。该制造方法可推广到其他碳-金属复合材料，该碳-金属复合材料由金属基质中的低维成分组成，用于改善电气和结构应用。该项目为高中生和博士后研究人员提供跨学科的研究、教育和培训机会，确保妇女和代表性不足的少数群体的参与。教育和研究一体化活动包括开发模块演示和实验室参观，以获得互动教学和学习体验，并提供新的跨学科课程和研究计划。碳纳米材料，如碳纳米管和石墨烯，具有优异的电学性能，远远超过铜等纯金属导体。为了利用这些吸引人的特性，碳纳米材料通常被分散在铜基中来制备碳-铜复合导体。然而，由于分散的纳米碳材料与铜基之间的界面不连续，这些导体的电性能较低。该研究项目旨在通过开发一种创新的制造技术来解决这些技术挑战，该技术涉及化学气相沉积(CVD)和在预压紧的铜泡沫中生长连续的石墨烯薄膜，然后进行“温和”压缩步骤。温和的压缩确保了石墨烯涂层泡沫铜的最终致密化，而不会损坏连续的石墨烯薄膜。本研究旨在解决以下基本问题：(1)提高石墨烯-铜复合材料电学性能的基本机制；(2)复合材料中石墨烯网络的连续性对其整体材料性能的影响；(3)除了不同的石墨烯-铜体积比的直接影响外，复合材料的材料行为与尺寸的关系。克服这些技术挑战对于设计和制造具有显著增强的电气性能的石墨烯-铜复合导体至关重要。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) grant supports research to establish the basis of a new manufacturing technique for the fabrication of ultrahigh electrical conductivity materials. The research exploits the excellent electrical conductivity of graphene, an emerging two-dimensional (2D) carbon nanomaterial, within a pure copper matrix. Fundamental multiscale and multi-physics studies will be performed in order to understand the fabrication and properties of graphene-copper composites critical to the achievement of scientific and technological advancements in high conductivity materials. The availability of ultrahigh conductivity materials meets the ever-increasing demand for high performance electrical conductors in electric vehicles, portable devices, and power grids, which impacts various industries and, hence, the U.S. economy. New experimental methods will be developed for controlling the continuity of graphene networks within a copper matrix to achieve electrical conductivities significantly higher than that of pure copper. The manufacturing approach is generalizable to other carbon-metal composites consisting of low dimensional constituents within metal matrices for improved electrical and structural applications. This project provides interdisciplinary research, education, and training opportunities for high school students to postdoctoral researchers, ensuring participation from women and under-represented minority groups. Educational and research integration activities include developing modular demonstrations and laboratory tours for interactive teaching and learning experiences and offering new interdisciplinary courses and research programs. Carbon nanomaterials, such as carbon nanotube and graphene, have excellent electrical properties far exceeding those of pure metal conductors such as copper. To exploit these attractive properties, carbon nanomaterials are often dispersed in a copper matrix to fabricate carbon-copper composite conductors. However, these conductors suffer from low electrical performance due to the discontinuous interfaces between the dispersed nanocarbon materials and the copper matrix. This research project seeks to address these technical challenges by developing an innovative manufacturing technique involving chemical vapor deposition (CVD) and growth of continuous graphene films in a pre-compacted copper foam followed by a ‘gentle’ compression step. The ‘gentle’ compression ensures that the final densification of the graphene-coated copper foam occurs without damaging the continuous graphene films. This research aims to resolve fundamental questions about (1) the underlying mechanisms for the enhanced electrical properties of graphene-copper composites; (2) the role of the continuity of graphene networks in the composite on their overall material properties; and (3) size-dependent material behavior of the composite besides the direct effect of different graphene-to-copper volume ratios. Overcoming these technical challenges is essential for designing and manufacturing graphene-copper composite conductors with significantly enhanced electrical properties.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.