Bundlet Model for Single-Wall Carbon Nanotubes, Nanocones and Nanohorns

2012 ◽  
Vol 2 (1) ◽  
pp. 48-98 ◽  
Author(s):  
Francisco Torrens ◽  
Gloria Castellano
Keyword(s):  
Carbon Nanotubes ◽  
Free Energy ◽  
Distribution Function ◽  
Carbon Nanotube ◽  
Interaction Energy ◽  
Organic Solvents ◽  
Cone Angle ◽  
Single Wall Carbon Nanotubes ◽  
Carbon Nanocones ◽  
Single Wall Carbon

This paper discusses the existence of single-wall carbon nanocones (SWNCs), especially nanohorns (SWNHs), in organic solvents in the form of clusters. A theory is developed based on a bundlet model describing their distribution function by size. Phenomena have a unified explanation in bundlet model in which free energy of an SWNC, involved in a cluster, is combined from two components: a volume one, proportional to number of molecules n in a cluster, and a surface one proportional to n1/2. Bundlet model enables describing distribution function of SWNC clusters by size. From purely geometrical differences, bundlet (SWNCs) and droplet (fullerene) models predict different behaviours. The SWNCs of various disclinations are investigated via energetic–structural analyses. Several SWNC’s terminations are studied, which are different among one another because of type of closing structure and arrangement. The packing efficiencies and interaction-energy parameters of SWNCs/SWNHs are intermediate between fullerene and single-wall carbon nanotube (SWNT) clusters; an in-between behaviour is expected. However, the properties of SWNCs, especially SWNHs, are calculated close to SWNTs. The structural asymmetry in the different SWNCs, entirely characterized by their cone angle, distinguishes the properties of some, such as P2.

Cluster Origin of Solvent Features of Fullerenes, Single-Wall Carbon Nanotubes, Nanocones, and Nanohorns

2014 ◽  
pp. 262-318
Author(s):  
Francisco Torrens ◽  
Gloria Castellano
Keyword(s):  
Carbon Nanotubes ◽  
Free Energy ◽  
Distribution Function ◽  
Carbon Nanotube ◽  
Interaction Energy ◽  
Organic Solvents ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon Nanotube ◽  
Carbon Nanocones ◽  
Single Wall Carbon

This chapter discusses the existence of single-wall carbon nanocones (SWNCs), especially nanohorns (SWNHs) in organic solvents in the form of clusters. A theory is developed based on a bundlet model describing their distribution function by size. Phenomena have a unified explanation in bundlet model in which free energy of an SWNC, involved in a cluster, is combined from two components: a volume one, proportional to number of molecules n in a cluster, and a surface one proportional to n1/2. A bundlet model enables describing distribution function of SWNC clusters by size. From purely geometrical differences, bundlet (SWNCs) and droplet (fullerene) models predict different behaviours. The SWNCs of various disclinations are investigated via energetic–structural analyses. Several SWNC’s terminations are studied which are different among one another because of the type of closing structure and arrangement. Packing efficiencies and interaction-energy parameters of SWNCs/SWNHs are intermediate between fullerene and single-wall carbon nanotube (SWNT) clusters.

Cluster Origin of Solvent Features of Fullerenes, Single-Wall Carbon Nanotubes, Nanocones, and Nanohorns

2012 ◽  
pp. 1-57
Author(s):  
Francisco Torrens ◽  
Gloria Castellano
Keyword(s):  
Carbon Nanotubes ◽  
Free Energy ◽  
Distribution Function ◽  
Carbon Nanotube ◽  
Interaction Energy ◽  
Organic Solvents ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon Nanotube ◽  
Carbon Nanocones ◽  
Single Wall Carbon

This chapter discusses the existence of single-wall carbon nanocones (SWNCs), especially nanohorns (SWNHs) in organic solvents in the form of clusters. A theory is developed based on a bundlet model describing their distribution function by size. Phenomena have a unified explanation in bundlet model in which free energy of an SWNC, involved in a cluster, is combined from two components: a volume one, proportional to number of molecules n in a cluster, and a surface one proportional to n1/2. A bundlet model enables describing distribution function of SWNC clusters by size. From purely geometrical differences, bundlet (SWNCs) and droplet (fullerene) models predict different behaviours. The SWNCs of various disclinations are investigated via energetic–structural analyses. Several SWNC’s terminations are studied which are different among one another because of the type of closing structure and arrangement. Packing efficiencies and interaction-energy parameters of SWNCs/SWNHs are intermediate between fullerene and single-wall carbon nanotube (SWNT) clusters.

Bundlet Model for Single-Wall Carbon Nanotubes, Nanocones and Nanohorns

2013 ◽  
pp. 228-284 ◽  
Author(s):  
Francisco Torrens ◽  
Gloria Castellano
Keyword(s):  
Carbon Nanotubes ◽  
Free Energy ◽  
Distribution Function ◽  
Carbon Nanotube ◽  
Interaction Energy ◽  
Cone Angle ◽  
Single Wall Carbon Nanotubes ◽  
Carbon Nanocones ◽  
Structural Asymmetry ◽  
Single Wall Carbon

This paper discusses the existence of single-wall carbon nanocones (SWNCs), especially nanohorns (SWNHs), in organic solvents in the form of clusters. A theory is developed based on a bundlet model describing their distribution function by size. Phenomena have a unified explanation in bundlet model in which free energy of an SWNC, involved in a cluster, is combined from two components: a volume one, proportional to number of molecules n in a cluster, and a surface one proportional to n1/2. Bundlet model enables describing distribution function of SWNC clusters by size. From purely geometrical differences, bundlet (SWNCs) and droplet (fullerene) models predict different behaviours. The SWNCs of various disclinations are investigated via energetic–structural analyses. Several SWNC’s terminations are studied, which are different among one another because of type of closing structure and arrangement. The packing efficiencies and interaction-energy parameters of SWNCs/SWNHs are intermediate between fullerene and single-wall carbon nanotube (SWNT) clusters; an in-between behaviour is expected. However, the properties of SWNCs, especially SWNHs, are calculated close to SWNTs. The structural asymmetry in the different SWNCs, entirely characterized by their cone angle, distinguishes the properties of some, such as P2.

Cluster Origin of Solvation Features of C-Nanostructures in Organic Solvents

2016 ◽  
pp. 189-293
Author(s):  
Francisco Torrens ◽  
Gloria Castellano
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Distribution Function ◽  
Diffusion Coefficient ◽  
Organic Solvents ◽  
Distribution Functions ◽  
Heat Of Solution ◽  
Carbon Nanocones ◽  
Single Wall Carbon ◽  
Sharp Concentration

The existence of fullerenes, Single-Wall Carbon Nanocones (SWNCs), especially Nanohorns (SWNHs), Single-Wall Carbon Nanotube (SWNT) (CNT) (NT), NT-Fullerene Bud (NT-BUD), Nanographene (GR) and GR-Fullerene Bud (GR-BUD) in cluster form is discussed in organic solvents. Theories are developed based on columnlet, bundlet and droplet models describing size-distribution functions. The phenomena present a unified explanation in the columnlet model in which free energy of cluster-involved GR comes from its volume, proportional to number of molecules n in cluster. Columnlet model enables describing distribution function of GR stacks by size. From geometrical considerations, columnlet (GR/GR-BUD), bundlet (SWNT/NT-BUD) and droplet (fullerene) models predict dissimilar behaviours. Interaction-energy parameters are derived from C60. An NT-BUD behaviour or further is expected. Solubility decays with temperature result smaller for GR/GR-BUD than SWNT/NT-BUD than C60 in agreement with lesser numbers of units in clusters. Discrepancy between experimental data of the heat of solution of fullerenes, CNT/NT-BUDs and GR/GR-BUDs is ascribed to the sharp concentration dependence of the heat of solution. Diffusion coefficient drops with temperature result greater for GR/GR-BUD than SWNT/NT-BUD than C60 corresponding to lesser number of units in clusters. Aggregates (C60)13, SWNT/NT-BUD7 and GR/GR-BUD3 are representative of droplet, bundlet and columnlet models.

Preparation of a Functional Enzyme–Carbon Nanotube Complex by the Immobilization of Superoxide Dismutase on Single-Wall Carbon Nanotubes

2018 ◽  
Vol 13 (7-8) ◽  
pp. 349-355 ◽  
Author(s):  
D. K. Shishkova ◽  
Yu. I. Khodyrevskaya ◽  
A. G. Kutikhin ◽  
M. S. Rybakov ◽  
R. A. Mukhamadiyarov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Superoxide Dismutase ◽  
Carbon Nanotube ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon

Self-Assembly Fabrication of High Performance Carbon Nanotubes Based FETs

2003 ◽  
Vol 772 ◽  
Author(s):  
Emmanuel Valentin ◽  
Stephane Auvray ◽  
Arianna Filoramo ◽  
Aline Ribayrol ◽  
Marcelo Goffman ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Self Assembly ◽  
High Performance ◽  
Field Effect Transistors ◽  
High Yield ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon ◽  
Assembled Monolayers ◽  
Self Assembled

AbstractWe describe the realization of high quality self-assembled single wall carbon nanotube field effect transistors (CNTFET). A method using self-assembled monolayers (SAMs) is used to obtain high yield selective deposition placement of single wall carbon nanotubes (SWNTs) on predefined regions of a substrate. This is achieved with individual or small bundles of SWNTs and with high densities suitable for fabrication of integrated devices. We show that such positioned SWNTs can be electrically contacted to realize high performance transistors, which very well compare with state-of-the-art CNTFETs. We therefore validate the self-assembly approach to reliably fabricate efficient carbon nanotube based devices.

Electrochemical Tuning of Single-Wall Carbon Nanotube Mat and Investigations on Actuator Mechanism

2004 ◽  
Vol 855 ◽  
Author(s):  
S. Gupta ◽  
M. Hughes ◽  
J. Robertson
Keyword(s):  
Carbon Nanotubes ◽  
Charge Transfer ◽  
Carbon Nanotube ◽  
Bond Length ◽  
Upper Bound ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon Nanotube ◽  
Single Wall Carbon ◽  
Electrochemical Tuning

ABSTRACTElectrochemical tuning of single-wall carbon nanotubes has been investigated using in situ Raman spectroscopy. We built a linear actuator from single-wall carbon nanotube mat and studied in several alkali metal (Li, Na, and K) and alkaline earth (Ca) halide solutions. The variation of bonding with electrochemical biasing was monitored using in situ Raman. This is since Raman can detect changes in C-C bond length: the radial breathing mode (RBM) at ∼190 cm−1 varies inversely with the nanotube diameter and the G band at ∼1590 cm−1 varies with the axial bond length. In addition, the intensities of both the modes vary significantly in a nonmonotonic manner pointing at the emptying/depleting or filling of the bonding and anti-bonding states - electrochemical charge injection. We discuss the variation of spectroscopic observables (intensity/frequency) of these modes providing valuable information on the charge transfer dynamics on the single-wall carbon nanotubes mat surface. We found the in-plane compressive strain (∼ -0.25%) and the charge transfer per carbon atom (fc ∼ -0.005) as an upper bound for the electrolytes used i.e. CaCl2. These results can be quantitatively understood in terms of the changes in the energy gaps between the one-dimensional van Hove singularities in the electron density of states arising possibly due to the alterations in the overlap integral of π bonds between the p orbitals of the adjacent carbon atoms. Moreover, the extent of variation of the absolute potential of the Fermi level or alternatively modification of band gap is estimated from modeling Raman intensity to be around 0.1 eV as an upper bound for CaCl2.

Electrical Resistance of Single-Wall Carbon Nanotubes with Determined Chiral Indices

2009 ◽  
Vol 1204 ◽  
Author(s):  
Letian Lin ◽  
Lu-Chang Qin ◽  
Sean Washburn ◽  
Scott Paulson
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Vapor Deposition ◽  
Electrical Resistance ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon ◽  
Transmission Electron ◽  
Highly Sensitive

AbstractThe properties of a carbon nanotube (CNT), in particular a single-wall carbon nanotube (SWNT), are highly sensitive to the atomic structure of the nanotube described by its chirality (chiral indices). We have grown isolated SWNTs on a silicon substrate using chemical vapor deposition (CVD) and patterned sub-micron probes using electron beam lithography. The SWNT was exposed by etching the underlying substrate for transmission electron microscope (TEM) imaging and diffraction studies. For each individual SWNT, its electrical resistance was measured by the four-probe method at room temperature and the chiral indices of the same SWNT were determined by nano-beam electron diffraction. The contact resistances were reduced by annealing to typically 3-5 kΩ. We have measured the I-V curve and determined the chiral indices of each nanotube individually from four SWNTs selected randomly – two are metallic and two are semiconducting. We will present the electrical resistances in correlation with the carbon nanotube diameter as well as the band gap calculated from the determined chiral indices for the semiconducting carbon nanotubes. These experimental results are also discussed in connection with theoretical estimations.

Photoconductivity Study of Modified Single-Wall Carbon Nanotube/ Oxotitanium Phthalocyanine

2007 ◽  
Vol 121-123 ◽  
pp. 631-636
Author(s):  
T. Li ◽  
X.B. Zhang ◽  
Y. Li ◽  
W.Z. Huang ◽  
X.Y. Tao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Charge Transfer ◽  
Carbon Nanotube ◽  
Chemical Modification ◽  
Single Wall Carbon Nanotubes ◽  
Charge Generation ◽  
Photoinduced Charge Transfer ◽  
Single Wall Carbon ◽  
Discharge Method ◽  
Photoinduced Charge

Single-wall Carbon nanotubes (SWNTs) bonded with dodecylamine groups were obtained by chemical modification. The modified SWNTs showed improved solubility in organic solvents. Both its chemical and aggregated structure was characterized by means of FTIR and TEM. The photoconductivity of oxotitanium phthalocyanine (TiOPc) doped with the modified SWNTs was investigated by xerographic photoinduced discharge method. The results showed that the photosensitivity of the double-layered photoreceptor composed of the SWNTs/TiOPc composite as charge generation material was higher than that of pristine TiOPc, and the sensitivity increased with the content of modified SWNTs in the composites. It is the photoinduced charge transfer between TiOPc and SWNTs that contributes to the improved photosensitivity of the modified SWNTs/TiOPc composites.

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