1.
Coluci, VR; dos Santos, RPB; Galvao, DS
Topologically Closed Macromolecules Made of Single Walled Carbon Nanotubes—'Super'-Fullerenes Journal Article
In: Journal of Nanoscience and Nanotechnology, vol. 10, no. 7, pp. 4378–4383, 2010.
@article{coluci2010topologically,
title = {Topologically Closed Macromolecules Made of Single Walled Carbon Nanotubes—'Super'-Fullerenes},
author = {Coluci, VR and dos Santos, RPB and Galvao, DS},
url = {http://www.ingentaconnect.com/content/asp/jnn/2010/00000010/00000007/art00040},
year = {2010},
date = {2010-01-01},
journal = {Journal of Nanoscience and Nanotechnology},
volume = {10},
number = {7},
pages = {4378--4383},
publisher = {American Scientific Publishers},
abstract = {We propose and theoretically investigated a new class of topologically closed macromolecules built using single walled carbon nanotubes. These macromolecules are based on the fullerene architecture. Classical molecular dynamics simulations were used to predict their stability, thermal, vibrational, and mechanical properties. These macromolecules, named 'super'-fullerenes, present high porosity, low density (∼1 g/cm3), and high surface area (≅2500 m2/g). Our results predict gas phase specific heat of about 0.4 Jg−1K−1 at room temperature and high flexibility under compressive strains. These properties make these hypothetical macromolecules good candidates for gas storage material and biomolecular sieves.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We propose and theoretically investigated a new class of topologically closed macromolecules built using single walled carbon nanotubes. These macromolecules are based on the fullerene architecture. Classical molecular dynamics simulations were used to predict their stability, thermal, vibrational, and mechanical properties. These macromolecules, named 'super'-fullerenes, present high porosity, low density (∼1 g/cm3), and high surface area (≅2500 m2/g). Our results predict gas phase specific heat of about 0.4 Jg−1K−1 at room temperature and high flexibility under compressive strains. These properties make these hypothetical macromolecules good candidates for gas storage material and biomolecular sieves.
2.
Dos Santos, SG; Pires, MS; Lemos, V; Freire, VN; Caetano, EWS; Galvao, DS; Sato, F; Albuquerque, EL
C60-derived nanobaskets: stability, vibrational signatures, and molecular trapping Journal Article
In: Nanotechnology, vol. 20, no. 39, pp. 395701, 2009.
@article{dos2009c60,
title = {C60-derived nanobaskets: stability, vibrational signatures, and molecular trapping},
author = {Dos Santos, SG and Pires, MS and Lemos, V and Freire, VN and Caetano, EWS and Galvao, DS and Sato, F and Albuquerque, EL},
url = {http://iopscience.iop.org/0957-4484/20/39/395701},
year = {2009},
date = {2009-01-01},
journal = {Nanotechnology},
volume = {20},
number = {39},
pages = {395701},
publisher = {IOP Publishing},
abstract = {C60-derived nanobaskets, with chemical formulae (symmetry point group) C40H10 (C5v), C39H12 (C3v), C46H12 (C2v), were investigated. Molecular dynamic simulations (MDSs) indicate that the molecules preserve their bonding frame for temperatures up to 300 K (simulation time 100 ps), and maintain atomic cohesion for at least 4 ps at temperatures up to 3500 K. The infrared spectra of the C60-derived nanobaskets were simulated through density functional theory (DFT) calculations, allowing for the attribution of infrared signatures specific to each carbon nanobasket. The possibility of using C60-derived nanobaskets as molecular containers is demonstrated by performing a DFT study of their bonding to hydrogen, water, and L-alanine. The carbon nanostructures presented here show a higher bonding energy (~1.0 eV), suggesting that a family of nanostructures, Cn-derived (n = 60,70,76,80, etc) nanobaskets, could work as molecular containers, paving the way for future developments such as tunable traps for complex molecular systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
C60-derived nanobaskets, with chemical formulae (symmetry point group) C40H10 (C5v), C39H12 (C3v), C46H12 (C2v), were investigated. Molecular dynamic simulations (MDSs) indicate that the molecules preserve their bonding frame for temperatures up to 300 K (simulation time 100 ps), and maintain atomic cohesion for at least 4 ps at temperatures up to 3500 K. The infrared spectra of the C60-derived nanobaskets were simulated through density functional theory (DFT) calculations, allowing for the attribution of infrared signatures specific to each carbon nanobasket. The possibility of using C60-derived nanobaskets as molecular containers is demonstrated by performing a DFT study of their bonding to hydrogen, water, and L-alanine. The carbon nanostructures presented here show a higher bonding energy (~1.0 eV), suggesting that a family of nanostructures, Cn-derived (n = 60,70,76,80, etc) nanobaskets, could work as molecular containers, paving the way for future developments such as tunable traps for complex molecular systems.
3.
Coluci, Vitor R; Sato, Fernando; Braga, Scheila F; Skaf, Munir S; Galvao, Douglas S
Rotational dynamics and polymerization of C60 in C60-cubane crystals: A molecular dynamics study Journal Article
In: The Journal of Chemical Physics, vol. 129, no. 6, pp. 064506, 2008.
@article{coluci2008rotational,
title = {Rotational dynamics and polymerization of C60 in C60-cubane crystals: A molecular dynamics study},
author = {Coluci, Vitor R and Sato, Fernando and Braga, Scheila F and Skaf, Munir S and Galvao, Douglas S},
url = {http://scitation.aip.org/content/aip/journal/jcp/129/6/10.1063/1.2965885},
year = {2008},
date = {2008-01-01},
journal = {The Journal of Chemical Physics},
volume = {129},
number = {6},
pages = {064506},
publisher = {AIP Publishing},
abstract = {We report classical and tight-binding molecular dynamics simulations of the C60fullerene and cubane molecular crystal in order to investigate the intermolecular dynamics and polymerization processes. Our results show that, for 200 and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations, while C60fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (≲1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (≳10 ps). The mechanisms underlying these dynamics are presented. Random copolymerizations among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure. Changes in the radial distribution function and electronic density of states indicate the coexistence of amorphous and crystalline phases. The different conformational phases that cubanes and fullerenes undergo during the copolymerization process are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report classical and tight-binding molecular dynamics simulations of the C60fullerene and cubane molecular crystal in order to investigate the intermolecular dynamics and polymerization processes. Our results show that, for 200 and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations, while C60fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (≲1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (≳10 ps). The mechanisms underlying these dynamics are presented. Random copolymerizations among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure. Changes in the radial distribution function and electronic density of states indicate the coexistence of amorphous and crystalline phases. The different conformational phases that cubanes and fullerenes undergo during the copolymerization process are discussed.
4.
Troche, KS; Coluci, VR; Rurali, R; Galvao, DS
Structural and electronic properties of zigzag carbon nanotubes filled with small fullerenes Journal Article
In: Journal of Physics: Condensed Matter, vol. 19, no. 23, pp. 236222, 2007.
@article{troche2007structural,
title = {Structural and electronic properties of zigzag carbon nanotubes filled with small fullerenes},
author = {Troche, KS and Coluci, VR and Rurali, R and Galvao, DS},
url = {http://iopscience.iop.org/0953-8984/19/23/236222},
year = {2007},
date = {2007-01-01},
journal = {Journal of Physics: Condensed Matter},
volume = {19},
number = {23},
pages = {236222},
publisher = {IOP Publishing},
abstract = {In this work we investigated the encapsulation of C20 and C30 fullerenes into semiconducting carbon nanotubes to study the possibility of bandgap engineering in such systems. Classical molecular dynamics simulations coupled to tight-binding calculations were used to determine the conformational and electronic properties of carbon nanotubes with an increasing fullerene concentration. We have observed that C20 fullerenes behave similarly to a n-type dopant while C30 can provide p-type doping in some cases. The combined incorporation of both types of fullerenes (hybrid encapsulation) into the same nanotube leads to a behaviour similar to that found in electronic pn-junctions. These aspects can be exploited in the design of nanoelectronic devices using semiconducting carbon nanotubes.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work we investigated the encapsulation of C20 and C30 fullerenes into semiconducting carbon nanotubes to study the possibility of bandgap engineering in such systems. Classical molecular dynamics simulations coupled to tight-binding calculations were used to determine the conformational and electronic properties of carbon nanotubes with an increasing fullerene concentration. We have observed that C20 fullerenes behave similarly to a n-type dopant while C30 can provide p-type doping in some cases. The combined incorporation of both types of fullerenes (hybrid encapsulation) into the same nanotube leads to a behaviour similar to that found in electronic pn-junctions. These aspects can be exploited in the design of nanoelectronic devices using semiconducting carbon nanotubes.
5.
Legoas, Sergio B; Giro, Ronaldo; Galvao, Douglas S
Molecular dynamics simulations of C6) nanobearings Journal Article
In: Chemical physics letters, vol. 386, no. 4, pp. 425–429, 2004.
@article{legoas2004molecular,
title = {Molecular dynamics simulations of C6) nanobearings},
author = {Legoas, Sergio B and Giro, Ronaldo and Galvao, Douglas S},
url = {http://www.sciencedirect.com/science/article/pii/S000926140400168X},
year = {2004},
date = {2004-01-01},
journal = {Chemical physics letters},
volume = {386},
number = {4},
pages = {425--429},
publisher = {Elsevier},
abstract = {Recently was reported an ultra-lubricated system based on C60 molecules deposited over graphite layers. In that work a stick-slip rolling model for C60 molecules was proposed to explain the observed ultra-low friction force. In this Letter, we report the first molecular dynamics studies for these systems. Our results show that the AB stacking is not observed and the main experimental features can be explained without invoking stick-slip motions.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recently was reported an ultra-lubricated system based on C60 molecules deposited over graphite layers. In that work a stick-slip rolling model for C60 molecules was proposed to explain the observed ultra-low friction force. In this Letter, we report the first molecular dynamics studies for these systems. Our results show that the AB stacking is not observed and the main experimental features can be explained without invoking stick-slip motions.
2010
5.
Coluci, VR; dos Santos, RPB; Galvao, DS
Topologically Closed Macromolecules Made of Single Walled Carbon Nanotubes—'Super'-Fullerenes Journal Article
In: Journal of Nanoscience and Nanotechnology, vol. 10, no. 7, pp. 4378–4383, 2010.
Abstract | Links | BibTeX | Tags: Fullerenes, New Structures, Super Carbons, Super Fullerenes
@article{coluci2010topologically,
title = {Topologically Closed Macromolecules Made of Single Walled Carbon Nanotubes—'Super'-Fullerenes},
author = {Coluci, VR and dos Santos, RPB and Galvao, DS},
url = {http://www.ingentaconnect.com/content/asp/jnn/2010/00000010/00000007/art00040},
year = {2010},
date = {2010-01-01},
journal = {Journal of Nanoscience and Nanotechnology},
volume = {10},
number = {7},
pages = {4378--4383},
publisher = {American Scientific Publishers},
abstract = {We propose and theoretically investigated a new class of topologically closed macromolecules built using single walled carbon nanotubes. These macromolecules are based on the fullerene architecture. Classical molecular dynamics simulations were used to predict their stability, thermal, vibrational, and mechanical properties. These macromolecules, named 'super'-fullerenes, present high porosity, low density (∼1 g/cm3), and high surface area (≅2500 m2/g). Our results predict gas phase specific heat of about 0.4 Jg−1K−1 at room temperature and high flexibility under compressive strains. These properties make these hypothetical macromolecules good candidates for gas storage material and biomolecular sieves.},
keywords = {Fullerenes, New Structures, Super Carbons, Super Fullerenes},
pubstate = {published},
tppubtype = {article}
}
We propose and theoretically investigated a new class of topologically closed macromolecules built using single walled carbon nanotubes. These macromolecules are based on the fullerene architecture. Classical molecular dynamics simulations were used to predict their stability, thermal, vibrational, and mechanical properties. These macromolecules, named 'super'-fullerenes, present high porosity, low density (∼1 g/cm3), and high surface area (≅2500 m2/g). Our results predict gas phase specific heat of about 0.4 Jg−1K−1 at room temperature and high flexibility under compressive strains. These properties make these hypothetical macromolecules good candidates for gas storage material and biomolecular sieves.
2009
4.
Dos Santos, SG; Pires, MS; Lemos, V; Freire, VN; Caetano, EWS; Galvao, DS; Sato, F; Albuquerque, EL
C60-derived nanobaskets: stability, vibrational signatures, and molecular trapping Journal Article
In: Nanotechnology, vol. 20, no. 39, pp. 395701, 2009.
Abstract | Links | BibTeX | Tags: Fullerenes, Molecular Dynamics, nanobaskets, nanobowls
@article{dos2009c60,
title = {C60-derived nanobaskets: stability, vibrational signatures, and molecular trapping},
author = {Dos Santos, SG and Pires, MS and Lemos, V and Freire, VN and Caetano, EWS and Galvao, DS and Sato, F and Albuquerque, EL},
url = {http://iopscience.iop.org/0957-4484/20/39/395701},
year = {2009},
date = {2009-01-01},
journal = {Nanotechnology},
volume = {20},
number = {39},
pages = {395701},
publisher = {IOP Publishing},
abstract = {C60-derived nanobaskets, with chemical formulae (symmetry point group) C40H10 (C5v), C39H12 (C3v), C46H12 (C2v), were investigated. Molecular dynamic simulations (MDSs) indicate that the molecules preserve their bonding frame for temperatures up to 300 K (simulation time 100 ps), and maintain atomic cohesion for at least 4 ps at temperatures up to 3500 K. The infrared spectra of the C60-derived nanobaskets were simulated through density functional theory (DFT) calculations, allowing for the attribution of infrared signatures specific to each carbon nanobasket. The possibility of using C60-derived nanobaskets as molecular containers is demonstrated by performing a DFT study of their bonding to hydrogen, water, and L-alanine. The carbon nanostructures presented here show a higher bonding energy (~1.0 eV), suggesting that a family of nanostructures, Cn-derived (n = 60,70,76,80, etc) nanobaskets, could work as molecular containers, paving the way for future developments such as tunable traps for complex molecular systems.},
keywords = {Fullerenes, Molecular Dynamics, nanobaskets, nanobowls},
pubstate = {published},
tppubtype = {article}
}
C60-derived nanobaskets, with chemical formulae (symmetry point group) C40H10 (C5v), C39H12 (C3v), C46H12 (C2v), were investigated. Molecular dynamic simulations (MDSs) indicate that the molecules preserve their bonding frame for temperatures up to 300 K (simulation time 100 ps), and maintain atomic cohesion for at least 4 ps at temperatures up to 3500 K. The infrared spectra of the C60-derived nanobaskets were simulated through density functional theory (DFT) calculations, allowing for the attribution of infrared signatures specific to each carbon nanobasket. The possibility of using C60-derived nanobaskets as molecular containers is demonstrated by performing a DFT study of their bonding to hydrogen, water, and L-alanine. The carbon nanostructures presented here show a higher bonding energy (~1.0 eV), suggesting that a family of nanostructures, Cn-derived (n = 60,70,76,80, etc) nanobaskets, could work as molecular containers, paving the way for future developments such as tunable traps for complex molecular systems.
2008
3.
Coluci, Vitor R; Sato, Fernando; Braga, Scheila F; Skaf, Munir S; Galvao, Douglas S
Rotational dynamics and polymerization of C60 in C60-cubane crystals: A molecular dynamics study Journal Article
In: The Journal of Chemical Physics, vol. 129, no. 6, pp. 064506, 2008.
Abstract | Links | BibTeX | Tags: C60, C70, Cubanes, Fullerenes, Molecular Dynamics, Rotor-Stator
@article{coluci2008rotational,
title = {Rotational dynamics and polymerization of C60 in C60-cubane crystals: A molecular dynamics study},
author = {Coluci, Vitor R and Sato, Fernando and Braga, Scheila F and Skaf, Munir S and Galvao, Douglas S},
url = {http://scitation.aip.org/content/aip/journal/jcp/129/6/10.1063/1.2965885},
year = {2008},
date = {2008-01-01},
journal = {The Journal of Chemical Physics},
volume = {129},
number = {6},
pages = {064506},
publisher = {AIP Publishing},
abstract = {We report classical and tight-binding molecular dynamics simulations of the C60fullerene and cubane molecular crystal in order to investigate the intermolecular dynamics and polymerization processes. Our results show that, for 200 and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations, while C60fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (≲1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (≳10 ps). The mechanisms underlying these dynamics are presented. Random copolymerizations among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure. Changes in the radial distribution function and electronic density of states indicate the coexistence of amorphous and crystalline phases. The different conformational phases that cubanes and fullerenes undergo during the copolymerization process are discussed.},
keywords = {C60, C70, Cubanes, Fullerenes, Molecular Dynamics, Rotor-Stator},
pubstate = {published},
tppubtype = {article}
}
We report classical and tight-binding molecular dynamics simulations of the C60fullerene and cubane molecular crystal in order to investigate the intermolecular dynamics and polymerization processes. Our results show that, for 200 and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations, while C60fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (≲1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (≳10 ps). The mechanisms underlying these dynamics are presented. Random copolymerizations among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure. Changes in the radial distribution function and electronic density of states indicate the coexistence of amorphous and crystalline phases. The different conformational phases that cubanes and fullerenes undergo during the copolymerization process are discussed.
2007
2.
Troche, KS; Coluci, VR; Rurali, R; Galvao, DS
Structural and electronic properties of zigzag carbon nanotubes filled with small fullerenes Journal Article
In: Journal of Physics: Condensed Matter, vol. 19, no. 23, pp. 236222, 2007.
Abstract | Links | BibTeX | Tags: Carbon Nanotubes, CNT encapsulation, Electronic Structure, Fullerenes, Peapods
@article{troche2007structural,
title = {Structural and electronic properties of zigzag carbon nanotubes filled with small fullerenes},
author = {Troche, KS and Coluci, VR and Rurali, R and Galvao, DS},
url = {http://iopscience.iop.org/0953-8984/19/23/236222},
year = {2007},
date = {2007-01-01},
journal = {Journal of Physics: Condensed Matter},
volume = {19},
number = {23},
pages = {236222},
publisher = {IOP Publishing},
abstract = {In this work we investigated the encapsulation of C20 and C30 fullerenes into semiconducting carbon nanotubes to study the possibility of bandgap engineering in such systems. Classical molecular dynamics simulations coupled to tight-binding calculations were used to determine the conformational and electronic properties of carbon nanotubes with an increasing fullerene concentration. We have observed that C20 fullerenes behave similarly to a n-type dopant while C30 can provide p-type doping in some cases. The combined incorporation of both types of fullerenes (hybrid encapsulation) into the same nanotube leads to a behaviour similar to that found in electronic pn-junctions. These aspects can be exploited in the design of nanoelectronic devices using semiconducting carbon nanotubes.
},
keywords = {Carbon Nanotubes, CNT encapsulation, Electronic Structure, Fullerenes, Peapods},
pubstate = {published},
tppubtype = {article}
}
In this work we investigated the encapsulation of C20 and C30 fullerenes into semiconducting carbon nanotubes to study the possibility of bandgap engineering in such systems. Classical molecular dynamics simulations coupled to tight-binding calculations were used to determine the conformational and electronic properties of carbon nanotubes with an increasing fullerene concentration. We have observed that C20 fullerenes behave similarly to a n-type dopant while C30 can provide p-type doping in some cases. The combined incorporation of both types of fullerenes (hybrid encapsulation) into the same nanotube leads to a behaviour similar to that found in electronic pn-junctions. These aspects can be exploited in the design of nanoelectronic devices using semiconducting carbon nanotubes.
2004
1.
Legoas, Sergio B; Giro, Ronaldo; Galvao, Douglas S
Molecular dynamics simulations of C6) nanobearings Journal Article
In: Chemical physics letters, vol. 386, no. 4, pp. 425–429, 2004.
Abstract | Links | BibTeX | Tags: C60, Fullerenes, Molecular Dynamics, Nanobearing, Tribology
@article{legoas2004molecular,
title = {Molecular dynamics simulations of C6) nanobearings},
author = {Legoas, Sergio B and Giro, Ronaldo and Galvao, Douglas S},
url = {http://www.sciencedirect.com/science/article/pii/S000926140400168X},
year = {2004},
date = {2004-01-01},
journal = {Chemical physics letters},
volume = {386},
number = {4},
pages = {425--429},
publisher = {Elsevier},
abstract = {Recently was reported an ultra-lubricated system based on C60 molecules deposited over graphite layers. In that work a stick-slip rolling model for C60 molecules was proposed to explain the observed ultra-low friction force. In this Letter, we report the first molecular dynamics studies for these systems. Our results show that the AB stacking is not observed and the main experimental features can be explained without invoking stick-slip motions.
},
keywords = {C60, Fullerenes, Molecular Dynamics, Nanobearing, Tribology},
pubstate = {published},
tppubtype = {article}
}
Recently was reported an ultra-lubricated system based on C60 molecules deposited over graphite layers. In that work a stick-slip rolling model for C60 molecules was proposed to explain the observed ultra-low friction force. In this Letter, we report the first molecular dynamics studies for these systems. Our results show that the AB stacking is not observed and the main experimental features can be explained without invoking stick-slip motions.
http://scholar.google.com/citations?hl=en&user=95SvbM8AAAAJ
