Catalytic Flame Synthesis of Carbon Nanotubes

公共摘要：碳纳米管的催化火焰合成碳纳米管（CNTs）定义了一类具有卓越物理和电磁性能的新型工程材料，具有无数潜在的应用，包括高强度聚合物、共聚物、复合材料、陶瓷、可成型形式、分子电子学和纳米级机器、超导体、生物分子到细胞的输送系统、燃料存储和电池、平板显示器和计算机存储设备。尽管已经开发了各种用于生产碳纳米管的技术，包括脉冲电弧放电、脉冲激光烧蚀和热化学气相沉积，但它们不容易或经济地扩展到大规模应用。燃烧合成材料的历史已经证明了可扩展性，并提供了连续、高效、大批量生产的潜力，而不需要昂贵的起始材料。因此，拟议的研究计划的目标是增加对催化碳纳米管形成和在电辅助火焰中生长的机制的基本理解，并利用这种理解来定义具有规定特性（例如单壁或多壁，直径，螺旋度）的高速率和高纯度碳纳米管合成的工艺条件。实验采用平面火焰滞点（预混）和平面火焰逆流（非预混）两种气动策略流场，表征燃料组成、火焰温度、惰性添加量、氢气添加量、氧气浓度、应变速率等可控工艺参数对碳纳米管性能的影响。将研究衬底中过渡金属（Ni、Fe和Co）的性质和含量对形成的碳纳米管的产量和质量的影响，以及电场对控制碳纳米管纯度、排列、螺旋度和生长速度的影响。先进的基于激光的诊断，包括自发拉曼光谱，激光诱导荧光和可调谐二极管激光吸收光谱被用来确定在碳纳米管形成的特定区域的局部气相化学物质浓度和温度。利用电子显微镜、原子力显微镜和表面拉曼光谱对碳纳米管材料的性质进行了表征。研究和实验设施被纳入纳米材料科学与工程课程。作为罗格斯大学数学、科学和工程女性道格拉斯项目的一部分，通过支持本科生研究，增加了未被充分代表的少数民族和女性在工程领域的参与。通过与行业、州和纳米材料研究中心合作，促进了对学生（高中、本科和研究生阶段）的高技术劳动力的培训。

Public AbstractAward CTS-0522556PI: Stephen D. TseCatalytic Flame Synthesis of Carbon NanotubesCarbon nanotubes (CNTs) define a new class of engineering materials with remarkable physical and electromagnetic properties, with a myriad of potential applications, including high-strength polymers, copolymers, composites, ceramics, moldable forms, molecular electronics and nano-scale machines, superconductors, delivery systems of bio-molecules to cells, fuel storage and batteries, flat-panel displays, and computer memory devices. Although various techniques have been developed for the production of CNTs, including pulsed arc discharge, pulsed laser ablation, and thermal chemical-vapor deposition, they are not readily or economically scalable for large-scale applications. Combustion synthesis of materials has demonstrated a history of scalability and offers the potential for continuous, efficient, high-volume production, without the need for expensive starting materials. As such, the objective of the proposed research program is to increase fundamental understanding of the mechanisms of catalytic CNT formation and growth in electrically-assisted flames, and utilization of that understanding to define process conditions that enable high-rate and high-purity synthesis of CNTs with prescribed characteristics (e.g. single- or multi-walled, diameter, helicity). The experiments are conducted using strategic aerodynamic flow fields, i.e. flat-flame stagnation-point (premixed) and flat-flame counterflow (non-premixed), to characterize the effects of fuel composition, flame temperature, inert addition, hydrogen addition, oxygen concentration, strain rate, and other controllable process parameters on CNT properties. The influence of the nature as well as the content of the transition metal (Ni, Fe, and Co) in the substrates on the yield and the quality of the CNTs formed will be investigated, along with the influence of electric fields in controlling CNT purity, alignment, helicity, and growth rate. Advanced laser-based diagnostics including spontaneous Raman spectroscopy, laser-induced fluorescence, and tunable diode laser absorption spectroscopy are employed to determine the local gas-phase chemical species concentrations and temperatures at the specific regions of CNT formation. The CNT material properties are characterized using electron microscopy, atomic force microscopy, and surface Raman spectroscopy. The research and experimental facility are incorporated into the curriculum on nanomaterials science and engineering. The involvement of underrepresented minorities and women in engineering is increased by supporting undergraduate research as part of the Douglass Project for Rutgers Women in Math, Science, and Engineering. The training of students (at high school, undergraduate, and graduate level) for the high-technology workforce is promoted by partnering with industry, state, and Center for Nanomaterials Research.