Invited Presentation: Mechanism of Spontaneous Carbon Nanotube Partition in Liquid Multiphase Systems

Ming  Zheng¹, Constantine  Khripin¹, Geyou Ao¹, Jeffrey A Fagan¹, Min Zhang², Yoichiro Ito², Hui Gui³, Chongwu  Zhou³

1. National Institute of Standards and Technology, Gaithersburg, MD, United States.

2. NIH, Bethesda, MD, United States.

3. University of Southern California, Los Angeles, CA, United States

In this presentation, we will explore the mechanism of spontaneous carbon nanotube partition in different liquid phases created by dissolved polymers. In general, carbon nanotube partition is chirality dependent and can be modulated by different chemical species. This provides a scalable and cost-effective way to purify and separate carbon nanotubes dispersed by many different types of surfactants. We show that the separation can be carried out in various schemes, from simple manual multi-step extractions to automated chromatography-based method. Very high purity metal-semiconductor and single chirality CNT separations have been achieved. While a quantitative understanding of the separation mechanism is still lacking, considerable insight has been gained on the role of carbon nanotube hydrophobicity, surface coating and its interaction with other molecules in the liquid phases. A working model of the separation mechanism will be presented.