Advanced Optical Characterization and Imaging of Single-Walled Carbon Nanotubes

在这个由化学系化学测量和成像计划资助的项目中，莱斯大学的R.Bruce Weisman教授正在开发新的方法来表征和提纯一类具有重要科学和技术意义的纳米材料：单壁碳纳米管(SWCNTs)。这些纳米管显示了许多非凡的性质，使它们成为当前追求基础科学和现实世界应用的研究人员的极大兴趣。然而，这一领域的进展往往受到以下困难的限制：难以找到样品中存在的特定纳米管结构的数量，评估纳米管的质量，在生物和环境样品中微量检测它们，以及将纳米管混合物分类为纯结构形式。该项目使用新颖的实验方法解决了这些挑战。这项研究将通过代表不足的少数民族和女性理科学生的参与和专业发展，产生更广泛的影响。此外，该项目的实验方法和结果将加快基于碳纳米管的新的、有经济价值的商业技术的开发。该项目将探索和开发方差光谱，这是一种新的光学技术，在整体和单粒子之间架起桥梁，可以揭示纳米粒子的浓度、发射效率、不均匀性和聚集。最近开发的一种方法将被用来直接测量量化单壁碳纳米管(SWCNT)样品的组成所需的绝对、特定于结构的吸收截面。改进的分析方法将有助于更有效地按长度对单壁碳纳米管进行分类。该项目还将侧重于提高检测和成像以痕量浓度存在于复杂样品中的单壁碳纳米管的灵敏度极限。

In this project funded by the Chemical Measurement and Imaging Program of the Division of Chemistry, Professor R. Bruce Weisman of Rice University is developing new ways to characterize and purify a scientifically and technologically important class of nanomaterials: single-walled carbon nanotubes (SWCNTs). These nanotubes display many remarkable properties that make them of great current interest to researchers pursuing basic science as well as real-world applications. However, progress in this field is often limited by difficulties in finding the amounts of specific nanotube structures that are present in samples, assessing the nanotube quality, detecting them in trace quantities in biological and environmental specimens, and sorting nanotube mixtures into pure structural forms. This project addresses these challenges using novel experimental methods. This research will provide broader impacts through the participation and professional development of underrepresented minority and women science students. In addition, the experimental methods and findings of the project should speed the development of new and economically valuable commercial technologies based on carbon nanotubes.The project will explore and develop variance spectroscopy, a new optical technique that serves as a bridge between bulk and single-particle regimes and can reveal nanoparticle concentrations, emission efficiencies, inhomogeneities, and aggregation. A recently developed method will be used to directly measure the absolute, structure-specific absorption cross-sections needed to quantify the compositions of single-walled carbon nanotube (SWCNT) samples. Improved analysis methods will support efforts to more effectively sort SWCNTs by length. The project will also focus on enhancing the sensitivity limits for detecting and imaging SWCNTs present in complex samples at trace concentrations.