The doped sites of locally functionalized single-walled carbon nanotubes show unique solvatochromic behaviors in their near-infrared photoluminescence.
Defect
doping of single-walled carbon nanotubes (SWCNTs) by local
chemical functionalization produces locally functionalized SWCNTs
(lf-SWCNTs) that emit red-shifted and bright photoluminescence (PL)
in near-infrared regions beyond 1000 nm (E
11
* PL) from localized
excitons trapped at doped sites in the tubes. In this study, we use
lf-SWCNTs with different doped sites such as proximal aryl-doped sites
and oxygen-doped sites (ether-type and epoxide-type) showing largely
red-shifted PL than typical E
11
* PL, which allow us to elucidate
the structural effects on PL solvatochromism (via organic solvent injection) and reveal the excitonic property variations
of the localized excitons. We correlate PL solvatochromic energy shifts
of the lf-SWCNTs with solvent orientation polarization parameters.
The proximal aryl-doped sites of bisaryl-modified lf-SWCNTs emit E
11
2* PL (∼1253 nm), and the observed solvatochromic energy shifts
appeared between those of the E
11 PL (∼980
nm) and E
11
* PL (∼1125 nm). The epoxide-type doped
sites of the oxygen-doped lf-SWCNTs emit E
11
*b PL (∼1250
nm), with almost no solvatochromism; this was totally different from
the trends seen for other PL, including E
11
*a PL from the
ether-type doped sites. The unique structure-dependent solvatochromism
is correlated with the (1) localization-induced polarizability or
dipole moment changes and (2) different degrees of exciton localization
at doped sites.
Single-walled carbon nanotubes (SWCNTs) emit photoluminescence (PL) in the near-infrared (NIR) region (>900 nm). To enhance their PL properties, defect doping via local chemical functionalization has been developed. The locally...
Azide functionalization produced luminescent sp2-type defects on single-walled carbon nanotubes, by which defect photoluminescence appeared in near infrared regions (1116 nm). Changes in exciton properties were induced by localization effects...
Monochiral single‐walled carbon nanotubes (SWCNTs) are indispensable for advancing the technology readiness level of nanocarbon‐based concepts. In recent times, many separation techniques have been developed to obtain specific SWCNTs from raw unsorted materials to catalyze the development in this area. This work presents how the aqueous two‐phase extraction (ATPE) method can be enhanced for the straightforward isolation of (6,4) SWCNTs in one step. Introducing nonionic surfactant into the typically employed mixture of anionic surfactants, which drive the partitioning, is essential to increasing the ATPE system's resolution. A thorough analysis of the parameter space by experiments and modeling reveals the underlying interactions between SWCNTs, surfactants, and phase‐forming agents, which drive the partitioning. Based on new insight gained on this front, a separation mechanism is proposed. Notably, the developed method is highly robust, which is proven by isolating (6,4) SWCNTs from several raw SWCNT materials, including SWCNT waste generated over the years in the laboratory.
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