High precision fractionator for use with density gradient ultracentrifugation

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Density gradient ultracentrifugation (DGU) is used for structural sorting of single-walled carbon nanotubes (SWCNTs).
• Separated SWCNT layers in DGU tubes are closely spaced, requiring precise extraction methods.
• Existing extraction techniques may lead to cross-contamination between sorted SWCNT fractions.

Purpose of the Study:

• To develop and present a novel computer-controlled device for selective aspiration of SWCNT layers from DGU gradients.
• To enable high-fidelity separation of closely spaced SWCNT fractions with minimal cross-contamination.

Main Methods:

• Design and implementation of a computer-controlled fractional aspiration system.
• Utilizing fine needles for precise layer targeting.
• Employing systematic needle movements and controlled, slow aspiration flow rates.
• Demonstration with DGU-sorted SWCNT samples.

Main Results:

• The device successfully aspirated multiple SWCNT sample layers under program control.
• Minimal cross-contamination was achieved between the aspirated layers.
• The system demonstrated effective performance on DGU-sorted SWCNT samples.

Conclusions:

• The developed computer-controlled device offers a highly selective method for extracting SWCNT layers post-DGU.
• This technology addresses the challenge of aspirating closely spaced fractions, improving sample purity.
• The device is a valuable tool for researchers working with structurally sorted single-walled carbon nanotubes.