Chromatographic separation of Single Walled Carbon nanotubes

Dr. Vardhan Bajpai

Mentor: Dr Barry Bauer

Polymer Division, MSEL

Bldg 224, Rm 213

Mail Stop 8542

Phone # 301-975-4877

Fax # 301-975-4924

Email # vardhan.bajpai@nist.gov

Sigma Xi member: NO

Category: Materials

Carbon nanotubes possess many very interesting optical, mechanical, electrical and chemical properties but their incorporation into various devices has still not been truly realized. The reason is the unavailability of purified carbon nanotubes of a single type. Existing synthetic methods produce complex impure mixtures possessing a distribution of lengths, diameters and chiralities, which restrict potential applications and also limit the development of metrologies. This work is focused on producing pure single wall carbon nanotubes (SWNTs) of controlled lengths and chiralities through solution-based chromatographic techniques such as size exclusion chromatography and ion-exchange chromatography. Size exclusion chromatography separates by tube size and provides information on SWNT stiffness.  Ion exchange chromatography sorts by charge affinity.  DNA based SWNT dispersions have different associations dependent on SWNT type and separation by tube diameter and chirality is achieved.