Counter Current Chromatography of Carbon Nanotubes

• Applicant: Dr. Benjamin Flavel
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation ; Analytical Chemistry ; Synthesis and Properties of Functional Materials ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2021 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 457038539

For the last 20 years carbon nanotubes (CNTs) have been touted as a material for the future due to their richly varying optical and electronic properties. It is possible to have single, double or multiple carbon walls, where each wall can either be semiconducting or metallic, each possess structure specific optical transitions, have exceptional properties such as high mobilities and environmental stability and come in a range of lengths. However, the initial excitement for CNTs was quickly dampened as it became apparent that it was not possible to selectively synthesize CNTs of arbitrarily defined structure (chirality) in the quantities required by industry. Post synthesis separation offered a solution to this problem, but, the complicated nature of these techniques coupled with small quantities, low yields, poor reproducibility, the use of expensive chemicals and easy structure selectivity only to small diameter semiconducting CNTs continue to hinder the appearance of CNTs in end-user applications. This project provides a solution to these long-standing problems with 3 work packages (WPs) that are aimed at transforming structure (chirality) and enantiomer sorted CNTs (most structures come in both left- and right-handed varieties), regardless of their diameter, wall number or electronic type, into a material that is cheap, large scale, and easy to prepare at large scale. In WP1 this will be achieved with a process known as Counter Current Chromatography (CCC), which will allow for CNTs to be simply injected into a system and sorted CNTs output within minutes. In WP2, CCC will allow for rapid screening of surfactant conditions to extend CNT separation to large diameter CNT species, both semiconducting and metallic, along with double-walled and multi-walled CNTs. WP3 will find new cheap water-based alternatives to the PEG/dextran system and allow for recovery and recycling of the two-phase components. This will ensure that the separation of SWCNTs is not only scalable but also cheap, time effective and industrially attractive.

• DFG Programme: Research Grants
• International Connection: Belgium, USA
• Major Instrumentation: Gegenstromchromatographie-System
• Instrumentation Group: 1350 Flüssigkeits-Chromatographen (außer Aminosäureanalysatoren 317), Ionenaustauscher
• Co-Investigator: Professorin Dr. Stephanie Reich
• Cooperation Partners: Professorin Dr. Sofie Cambré; Dr. Jeffrey Fagan; Professor Dr. Wim Wenseleers; Dr. Ming Zheng