SBIR Phase I: Enabling Low-Temperature Synthesis of Vertically Aligned Carbon-Nanotubes by Selective Heating of Catalyst

该小型企业创新研究（SBIR）第一阶段项目将开发一种低温合成定向碳纳米管（CNT）和纳米纤维（CNF）的新工艺。 CNT/CNF被广泛研究用于制造新型纳米材料和纳米器件。 这种制造的前景目前受到CNT/CNF合成过程中高（高于500摄氏度）表面温度的限制，这通常会导致纳米材料或器件损坏。我们提出开发一种新的处理系统，其中CNT/CNF将在低温下生长，这是由于（i）使用等离子体增强化学气相沉积（PECVD）工艺在低温下在纳米颗粒的表面上递送烃供应，和（ii）使用催化放热反应和射频（RF）选择性加热催化纳米颗粒由RF源产生的电磁场，除了用于维持PECVD反应器中的放电的电磁场之外。这一目标将通过CFDRC的理论努力和田纳西大学诺克斯维尔分校（UTK）的实验研究相结合来实现。理论工作将致力于CNT/CNF合成的分析和多尺度计算设计，使用气体/等离子体相过程的反应器尺度模拟，CNT生长的动力学Monte Carlo分析，以及原子自组装成CNT的分子动力学建模。第一阶段将展示所提出的概念的可行性，使用现有的PECVD反应器在UTK的CNT/CNF生长。第二阶段将致力于建立一个原型的制造反应器的开发过程。目前，碳纳米管的生产量非常小，每克成本超过黄金。 相结合的第一阶段和第二阶段的努力将导致一种新的处理系统，用于在温度敏感材料表面的选择性位置直接合成垂直排列的CNT结构。直接的应用包括制造基于CNT的场发射显示器、药物微反应器、生物和化学传感器、原子力显微镜的探针尖端和X射线设备中的冷阴极。

This Small Business Innovation Research (SBIR) Phase I project will develop a new process of low-temperature synthesis of aligned carbon nanotubes (CNTs) and nanofibers (CNFs). CNTs/CNFs are widely studied for manufacturing of novel nanomaterials and nanodevices. The prospects of this manufacturing are currently limited by the high (above 500 deg C) surface temperature during CNT/CNF synthesis, which often results in nanomaterial or device damage. We propose to develop a novel processing system where CNTs/CNFs will be grown at low temperature due to (i) delivering a supply of hydrocarbons on the surfaces of nanoparticles at low temperature using a plasma-enhanced chemical vapor deposition (PECVD) process, and (ii) selective heating of catalytic nanoparticles using catalytic exothermic reactions and radio-frequency (RF) electromagnetic fields generated by an RF source additional to that used to sustain discharge in PECVD reactor. This goal will be achieved by a combination of theoretical efforts at CFDRC and experimental research at the University of Tennessee at Knoxville (UTK). Theoretical efforts will be devoted to the analysis and multi-scale computational design of CNT/CNF synthesis using a reactor-scalesimulation of gas/plasma-phase processes, a Kinetic Monte Carlo analysis of the growth of CNTs, and a Molecular Dynamic modeling of self-assembly of atoms into CNTs. Phase I will show the feasibility of the proposed concepts using existing PECVD reactors for CNT/CNF growth at UTK. Phase II will be devoted to building a prototype of manufacturing reactor for the developed processes.Currently, CNTs are produced in very small quantities and cost more per gram than gold. The combined Phase I and Phase II efforts will result in a novel processing system for a direct synthesis of vertically aligned CNT structures at selective locations on the surfaces of temperature-sensitive materials. Immediate applications include manufacturing of CNT-based field emitters displays, pharmaceutical micro-reactors, bio and chemical sensors, probe tips for atomic force microscopes, and cold cathodes in X-ray devices.