Separation of double-wall carbon nanotubes by electronic type and diameter

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Carbon nanotubes (CNTs) are crucial nanomaterials with diverse applications.
• Separating single-wall (SWCNTs) from double-wall carbon nanotubes (DWCNTs) remains a significant challenge.
• Precise separation of DWCNTs by electronic structure and diameter is essential for targeted applications.

Purpose of the Study:

• To introduce an efficient procedure for isolating and separating double-wall carbon nanotubes (DWCNTs).
• To demonstrate sequential separation of DWCNTs by electronic structure and diameter using aqueous two-phase extraction (ATPE).
• To present analytical ultracentrifugation (AUC) as a novel method for DWCNT characterization and purity assessment.

Main Methods:

• Rate zonal ultracentrifugation (RZU) for initial DWCNT enrichment.
• Aqueous two-phase extraction (ATPE) for sequential separation based on electronic structure and diameter.
• Analytical ultracentrifugation (AUC) for characterizing DWCNT purity and comparing separation schemes.

Main Results:

• RZU followed by sequential ATPE yielded highly enriched DWCNT samples.
• Single-step ATPE (redox sorting) resulted in SWCNT/DWCNT mixtures.
• AUC confirmed the superior purity of DWCNTs obtained through the RZU-ATPE combined method.

Conclusions:

• The RZU and sequential ATPE method offers significant advancements in DWCNT processing and separation.
• This approach enables precise sorting of DWCNTs by electronic structure and diameter.
• AUC provides a valuable tool for analyzing DWCNT purity and validating separation techniques.