Effect of Substituents and Initial Degree of Functionalization of Alkylated Single‐Walled Carbon Nanotubes on Their Thermal Stability and Photoluminescence Properties
Alkylated single‐walled carbon nanotubes (SWNTs) have been thermally treated to determine the influence of substituents and the degree of functionalization on their thermal stability and photoluminescence (PL) properties. Alkylated SWNTs were prepared by treating SWNTs with sodium naphthalenide and...
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Published in | Chemistry : a European journal Vol. 23; no. 8; pp. 1789 - 1794 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Germany
Wiley Subscription Services, Inc
03.02.2017
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Subjects | |
Online Access | Get full text |
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Summary: | Alkylated single‐walled carbon nanotubes (SWNTs) have been thermally treated to determine the influence of substituents and the degree of functionalization on their thermal stability and photoluminescence (PL) properties. Alkylated SWNTs were prepared by treating SWNTs with sodium naphthalenide and alkyl bromide. The defunctionalization of the alkylated SWNTs was monitored by absorption and Raman spectra. Selective recovery of the characteristic absorption and radial breathing mode peaks was observed during the thermal treatment, which indicates that the thermal stability of the alkylated SWNTs decreases with increases in SWNT diameter and degree of functionalization. n‐Butylated and phenethylated SWNTs showed higher thermal stability than sec‐butylated and benzylated SWNTs for a similar degree of functionalization, respectively. The diameter selectivity and effect of substituents on the thermal elimination reaction were confirmed by density functional theory. In addition, it was shown that the initial degree of functionalization of the alkylated SWNTs, with the alkyl group and degree of functionalization being kept constant after thermal treatment, strongly affects their PL properties; Stokes shift, and PL peak intensity.
Bigger isn′t always better: Alkylated single‐walled carbon nanotubes (SWNTs‐R) have been prepared and their subsequent thermal treatment studied by absorption and Raman spectroscopy. The substituents and initial degree of functionalization of the SWNTs‐R were found to have an important effect on their thermal stability and photoluminescence properties (see figure). The observations are supported by the dissociation energies of the SWNTs‐R, determined by DFT. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0947-6539 1521-3765 |
DOI: | 10.1002/chem.201604282 |