Identification and separation of metallic and semiconducting carbon nanotubes

2017 ◽  
Author(s):  
Katalin Kamarás ◽  
Àron Pekker
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Electronic Structure ◽  
Transport Properties ◽  
Chemical Reactions ◽  
Selection Methods ◽  
Conductive Coatings ◽  
Semiconducting Properties ◽  
Transparent Conductive Coatings ◽  
Semiconducting Behavior

This article describes the identification and separation of metallic and semiconducting carbon nanotubes according to their electric properties. It first provides an overview of the electronic structure of nanotubes, focusing on how their metallic and semiconducting properties arise. It then considers the most widely used characterization techniques used in determining metallic or semiconducting behavior, including Raman spectroscopy and photoluminescence measurements. It also discusses specific chirality-selective growth techniques, physical postgrowth selection methods, enrichment by chirality-sensitive chemical reactions, and modification of transport properties without change in chirality. The article concludes with a review of some applications of metallic and semiconducting carbon nanotubes as transparent conductive coatings.

Fabrication of flexible transparent conductive coatings based on single-walled carbon nanotubes

2013 ◽  
Vol 50 (1) ◽  
pp. 23-28 ◽  
Author(s):  
K. F. Akhmadishina ◽  
I. I. Bobrinetskii ◽  
R. A. Ibragimov ◽  
I. A. Komarov ◽  
A. M. Malovichko ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Single Walled Carbon Nanotubes ◽  
Conductive Coatings ◽  
Single Walled Carbon ◽  
Transparent Conductive Coatings ◽  
Walled Carbon Nanotubes

scholarly journals Theoretical research on the electronic structure and transport properties of nitrogen doping chiral carbon nanotubes

2011 ◽  
Vol 60 (2) ◽  
pp. 027307
Author(s):  
Wei Yan ◽  
Hu Hui-Fang ◽  
Wang Zhi-Yong ◽  
Cheng Cai-Ping ◽  
Chen Nan-Ting ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Structure ◽  
Transport Properties ◽  
Nitrogen Doping ◽  
Theoretical Research ◽  
Chiral Carbon

Electronic Structure Benchmark Calculations of Inorganic and Biochemical Carboxylation Reactions

2018 ◽  
Author(s):  
Oscar A. Douglas-Gallardo ◽  
David A. Sáez ◽  
Stefan Vogt-Geisse ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Electronic Structure ◽  
Chemical Reactions ◽  
Density Functional ◽  
Correlation Energy ◽  
Electronic Energy ◽  
Basis Sets ◽  
Electronic Correlation ◽  
Correct Description ◽  
Carbon Dioxide Co2 ◽  
High Level

<div><div><div><p>Carboxylation reactions represent a very special class of chemical reactions that is characterized by the presence of a carbon dioxide (CO2) molecule as reactive species within its global chemical equation. These reactions work as fundamental gear to accomplish the CO2 fixation and thus to build up more complex molecules through different technological and biochemical processes. In this context, a correct description of the CO2 electronic structure turns out to be crucial to study the chemical and electronic properties associated with this kind of reactions. Here, a sys- tematic study of CO2 electronic structure and its contribution to different carboxylation reaction electronic energies has been carried out by means of several high-level ab-initio post-Hartree Fock (post-HF) and Density Functional Theory (DFT) calculations for a set of biochemistry and inorganic systems. We have found that for a correct description of the CO2 electronic correlation energy it is necessary to include post-CCSD(T) contributions (beyond the gold standard). These high-order excitations are required to properly describe the interactions of the four π-electrons as- sociated with the two degenerated π-molecular orbitals of the CO2 molecule. Likewise, our results show that in some reactions it is possible to obtain accurate reaction electronic energy values with computationally less demanding methods when the error in the electronic correlation energy com- pensates between reactants and products. Furthermore, the provided post-HF reference values allowed to validate different DFT exchange-correlation functionals combined with different basis sets for chemical reactions that are relevant in biochemical CO2 fixing enzymes.</p></div></div></div>

Structural Conductivity of Carbon Nanotubes

2008 ◽  
Vol 59 (10) ◽  
pp. 1169-1171 ◽  
Author(s):  
Zoltan Borsos ◽  
Viorel-Puiu Paun ◽  
Irinel Casian Botez ◽  
Cristina-Maria Stoica ◽  
Petrica Vizureanu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fractal Dimension ◽  
Electrical Properties ◽  
Transport Properties ◽  
Structural Form ◽  
Structural Symmetry

In this paper, the explicit connection between the high structural symmetry of the carbon nanotubes and the electrical properties is studied. An interesting path effect on the transport properties will be proved. For a bidimensional lattice, the conductivity sx depends on the structural form, which determines the shape of electron path, respectively it is direct proportional to the fractal dimension of this path.

scholarly journals Effect of Size of Multiwalled Carbon Nanotubes Dispersed in Gear Oils for Improvement of Tribological Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Kodanda Rama Rao Chebattina ◽  
V. Srinivas ◽  
N. Mohan Rao
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Ball Milling ◽  
Multiwalled Carbon Nanotubes ◽  
Tribological Properties ◽  
Extreme Pressure ◽  
Multiwalled Carbon ◽  
Pristine Mwcnts ◽  
Gear Oil ◽  
The Stability

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.

scholarly journals Exploring the Franck-Condon region of a photoexcited charge transfer complex in solution to interpret femtosecond stimulated Raman spectroscopy: excited state electronic structure methods to unveil non-radiative pathways

2021 ◽  
Author(s):  
Federico Coppola ◽  
Paola Cimino ◽  
Umberto Raucci ◽  
Maria Gabriella Chiariello ◽  
Alessio Petrone ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Electronic Structure ◽  
Excited State ◽  
Charge Transfer ◽  
Charge Transfer Complex ◽  
Main Role ◽  
Photoinduced Charge Transfer ◽  
Electronic Structure Methods ◽  
Franck Condon ◽  
Photoinduced Charge

We present electronic structure methods to unveil non-radiative pathways of photoinduced charge transfer (CT) reactions that play a main role in photophysics and light harvesting technologies. A prototypical π-stacked molecular...

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