Polymer Nanostructures as Thermal Interface Materials

提案CBET-1133071 PI：Baratunda Cola，格鲁吉亚理工学院本研究的目的是进行基础研究，以确定由共轭聚合物纳米管和纳米线阵列制成的高性能多功能热界面材料（TIM）的加工-结构-性能关系。 表面之间的小接触面积和低导热率是限制TIM性能的两个主要因素。 最近，共轭聚合物纳米管阵列被证明在界面中的近80%的表面上实现干接触。虽然这种机械接触面积的增强是有前途的，但尚未研究通过这种界面的热传输。 单个聚合物链的热导率可以高于一半以上的纯金属的热导率;然而，在基于聚合物的TIM中还没有实现这样高的值，因为随机取向的链之间的声子散射限制了本体聚合物中的热传输。导热性的显著改善可以通过在热流方向上对齐组成链来实现，这在聚合物纳米管和纳米线的制造过程中自然发生。合成和表征将被用来寻求理解的热传输在共轭聚合物纳米管和纳米线阵列作为TIM。 该项目的长期目标是实现下一代电子器件和封装的热管理，同时激发热传输、聚合物科学和纳米技术界面的广泛研究兴趣。通过共轭聚合物纳米管和纳米线阵列的热传输配置为一种新型的热界面材料，产生大的表面接触面积和粘合力，和低热阻将从根本上加以研究。 在高度排列和结晶的共轭聚合物纳米结构中观察到的热导率增强机制将被揭示。 一个全面的实验技术框架将被开发，以获得前所未有的洞察热传输在共轭聚合物纳米管和纳米线。 将建立将工艺参数与聚合物结构以及最终聚合物纳米线和纳米管的热、机械和电学性质联系起来的必要的比例关系。阵列形态和热和粘合剂的界面性能的共轭聚合物纳米管和纳米线之间的关系将被量化和配置，最大限度地减少界面热阻将被揭示。 对共轭聚合物纳米管和纳米线中的热传输的研究可能揭示工程热传输和电传输以创建定制的多功能界面材料的新可能性。 该项目的成功可以使具有成本效益的材料用于先进电子系统和设备的热管理，从而导致计算，通信，电子，航空航天和国防工业的新技术和应用。 新发现将通过专利、技术出版物和潜在的技术转让，通过格鲁吉亚科技公司传播给一家初创公司。先进技术开发中心（ATDC）。ADTC位于PI实验室附近，为成员公司提供种子资金和技术孵化空间。 跨多个学科的研究，教学和推广计划的整合，包括聚合物科学和纳米技术，将影响格鲁吉亚理工学院本科，研究生和研究生水平的多元化学生团体的教育和培训。最后，PI将邀请Dekalb县的高中教师和学生参加外联活动，包括亲自接触先进材料和热技术。

Proposal CBET-1133071PI: Baratunda Cola, Georgia Institute of TechnologyThe objective of this research is to conduct fundamental investigations towards the determination of the processing-structure-property relationship in high-performance, multifunctional thermal interface materials (TIMs) made of ð-conjugated polymer nanotube and nanowire arrays. Small contact area between surfaces and low thermal conductivity are two leading factors that limit the performance of TIMs. Recently, ð-conjugated polymer nanotube arrays were demonstrated to achieve dry contact over nearly 80% of the surface in an interface. While this enhancement to mechanical contact area is promising, thermal transport through such interfaces has not been studied. Individual polymer chains can have thermal conductivities that are higher than the thermal conductivities of more than half of the pure metals; however, such high values have not been realized in polymer-based TIMs because phonon scattering between randomly oriented chains limits thermal transport in bulk polymers. Significant improvements to thermal conductivity can be achieved by aligning constituent chains in the direction of heat flow, which occurs naturally during the fabrication of polymer nanotubes and nanowires. Synthesis and characterization will be used to seek understanding of thermal transport in ð-conjugated polymer nanotube and nanowire arrays used as TIMs. The long-term goal of this project is to enable thermal management of next-generation electronic devices and packages while concurrently exciting broad research interests at the interface of thermal transport, polymer science, and nanotechnology.Thermal transport through arrays of ð-conjugated polymer nanotubes and nanowires configured as a new type of thermal interface material that produces large surface contact areas and adhesive forces, and low thermal resistances will be studied fundamentally. The thermal conductivity enhancement mechanism observed in highly aligned and crystalline ð-conjugated polymer nanostructures will be revealed. A comprehensive framework of experimental techniques will be developed to gain unprecedented insight into thermal transport in ð-conjugated polymer nanotubes and nanowires. Necessary scaling relationships that link process parameters to polymer structure and ultimately the thermal, mechanical and electrical properties of polymer nanowires and nanotubes will be established. The relationship between array morphology and thermal and adhesive interface properties of ð-conjugated polymer nanotubes and nanowires will be quantified and configurations that minimize thermal interface resistance will be revealed. Studies on thermal transport in ð-conjugated polymer nanotubes and nanowires may reveal new possibilities for engineering both thermal and electrical transport to create tailored, multifunctional interface materials. The success of this project could enable cost-effective materials for thermal management of advanced electronic systems and devices leading to new technologies and applications in the computing, communications, electronics, aerospace and defense industries. New discoveries will be disseminated through patents, technical publications and potential technology transfer to a start-up company through Georgia Tech?s Advanced Technology Development Center (ATDC). ADTC is located in close proximity to the PIs labs and provides seed funding and technology incubation space to member companies. Integration of research, teaching, and outreach programs across multiple disciplines, including polymer science and nanotechnology, will impact the education and training of a diverse student body covering the undergraduate, graduate and post-graduate level at Georgia Tech. Finally, the PIs will engage high school teachers and students from Dekalb County in outreach activities involving hands-on exposure to advanced materials and thermal technologies.