Purification, separation and extraction of inner tubes from double-walled carbon nanotubes by tailoring density gradient ultracentrifugation using optical probes

Autor(en)

Philip Rohringer, Lei Shi, Xianjie Liu, Kazuhiro Yanagi, Thomas Pichler

Abstrakt

We studied the effect of varying sonication and centrifugation parameters on double-walled carbon nanotubes (DWCNT) by measuring optical absorption and photoluminescence (PL) of the samples. We found that by using a low sonication intensity before applying density gradient ultracentrifugation (DGU), only inner tube species with a diameter ⩽⩽0.8 nm can be identified in absorption measurements. This is in stark contrast to the result after sonicating at higher intensities, where also bigger inner tubes can be found. Furthermore, by comparing PL properties of samples centrifugated either with or without a gradient medium, we found that applying DGU greatly enhances the PL intensity, whereas centrifugation at even higher speeds but without a gradient medium results in lower intensities. This can be explained by extraction of inner tubes from their host outer tubes in a two-stage process: the different shearing forces from the sonication treatments result in some DWCNT to be opened, whereas others stay uncut. A subsequent application of DGU leads to the extraction of the inner tubes or not if the host nanotube stayed uncut or no gradient medium was used. This work shows a pathway to avoid this phenomenon to unravel the intrinsic PL from inner tubes of DWCN

Organisation(en)

Elektronische Materialeigenschaften

Externe Organisation(en)

Tokyo Metropolitan University, Linköping University

Journal

Carbon

Band

74

Seiten

282-290

Anzahl der Seiten

9

ISSN

0008-6223

DOI

https://doi.org/10.1016/j.carbon.2014.03.033

Publikationsdatum

08-2014

Peer-reviewed

Ja

ÖFOS 2012

103020 Oberflächenphysik, 103018 Materialphysik, 103009 Festkörperphysik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Chemie, Allgemeine Materialwissenschaften

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/74787417-2fc0-494c-9424-906e6eda1ff1