Computation of the static polarizabilities of multi-wall carbon nanotubes and fullerites using a Gaussian regularized point dipole interaction model

Langlet, R.; Devel, M.; Lambin, Philippe

doi:10.1016/j.carbon.2006.05.050

Cited by 38 publications

(37 citation statements)

References 69 publications

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“…(13) shows that the surface energy of CNSs directly determines the core size. Base on the finding that electric field would induce polarizable carbon atoms of CNTs 23 and dipole molecule on surface would influence its surface energy, 24 through electric field, we may control the core size of CNSs by changing the effective surface energy. Equation (13) also shows that the length of graphene influences the core size of CNSs.…”

Section: U R Ij Ijk Ijklmentioning

confidence: 99%

Tunable Core Size of Carbon Nanoscrolls

Shi¹,

Pugno²,

Gao³

2010

Jnl of Comp & Theo Nano

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We study the equilibrium core radius of a carbon nanoscroll (CNS) formed from spontaneous rolling of a graphene sheet. By a balance between the elastic bending energy and the van der Waals interaction energy in the system, we derive an analytical relation between the surface energy, the bending stiffness, the interlayer spacing, the length of a graphene sheet and the core radius of the resulting CNS. This relation is then quantitatively verified by molecular dynamics simulations. Our work immediately suggests that the core size of a CNS can be actively controlled for applications such as tunable water and ion channels, molecular sensors, as well as flexible gene and drug delivery systems.Keywords: Carbon Nanoscrolls, Molecular Dynamics, Core Size.Carbon nanoscralls (CNSs), also referred to as buckyrolls, may have numerous applications in nanotechnology due to their unique properties. So far most previous studies have been focused on carbon nanotube (CNT)-based nano-or nano-bio-systems, such as molecular probes or sensors, 1 gene or drug delivery systems. 2 Specifically, CNT-water, 3 4 CNT-CNT, 5 CNT-DNA oligonucleotides 6 and CNT-peptide 7 systems have been studied for encapsulating different types of molecules inside the CNTs. One disadvantage of the CNT-based systems is that the core size of CNTs is uncontrollable due to their closed structure. For applications such as tunable water and ion channels, molecular sensors, as well as flexible gene and drug delivery systems, it might be desirable to develop nanostructures with tunable core sizes. Here we show that carbon nanoscrolls may be a perfect candidate for such applications. Although CNSs were experimentally discovered in 2003 8 9 (see also Ref.[10]) and also investigated extensively by molecular dynamics simulations, [11][12][13][14][15][16] a quantitative theory describing their existence and assembly process is still unavailable. In the following, we present a theory on the dynamics and equilibrium state of this assembly process and show that the theoretical predictions are in excellent agreement with molecular dynamics simulations.Figure 1(A) shows a graphene sheet of length B and width L rolled up into a scroll with inner core radius * Author to whom correspondence should be addressed. r 0 , outer radius R and interlayer spacing t which can be described by a radial function asThe total length of the graphene sheet iswhere N is the number of coils. The elastic energy per unit area in the graphene is taken aswhere D is the bending stiffness. Note that dA ≈ Lrd . The total elastic energy in the scroll is thus obtained by integrating Eq. (3) asConsider an infinitesimal change in the core radius r 0 of the scroll. The change in strain energy would beIt can be shown that dN dr 0 = − N R

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Section: U R Ij Ijk Ijklmentioning

confidence: 99%

Tunable Core Size of Carbon Nanoscrolls

Shi¹,

Pugno²,

Gao³

2010

Jnl of Comp & Theo Nano

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“…Recently studied picoseconds-long first-principle MD with electronic structure calculations using density functional theory are only possible for small solutes such as methane (28) and benzene in water (29,30). Other studies have modeled polarization in carbon nanotubes (31)(32)(33)(34)(35). Vernov and Steele (36) considered a chargeinduced dipole moment and static quadrupole moments on a graphite surface, whereas Zimmerli et al (37) included a curvatureinduced static dipole in simulations of carbon nanotubes.…”

mentioning

confidence: 99%

Remarkable patterns of surface water ordering around polarized buckminsterfullerene

Chopra

Levitt

2011

Proc. Natl. Acad. Sci. U.S.A.

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Accurate description of water structure affects simulation of protein folding, substrate binding, macromolecular recognition, and complex formation. We study the hydration of buckminsterfullerene, the smallest hydrophobic nanosphere, by molecular dynamics simulations using a state-of-the-art quantum mechanical polarizable force field (QMPFF3), derived from quantum mechanical data at the MP2/aug-cc-pVTZ(-hp) level augmented by CCSD(T). QMPFF3 calculation of the hydrophobic effect is compared to that obtained with empirical force fields. Using a novel and highly sensitive method, we see polarization increases ordered water structure so that the imprint of the hydrophobic surface atoms on the surrounding waters is stronger and extends to long-range. We see less water order for empirical force fields. The greater order seen with QMPFF3 will affect biological processes through a stronger hydrophobic effect.B uckminsterfullerene (C 60 ), commonly known as the buckyball, has been the focus of many experimental and theoretical studies because of its promise in both biomedicine and nanomaterials (1-8). Carbon nanotubes, a nanomaterial similar to fullerenes, exhibit unique mechanical properties, electrical and heat conductivity; they are often hailed as a twenty-first century material that could revolutionize a number of industries (2). The behavior of fullerenes in water is of special interest for biosensors (9). Moreover, water-soluble buckyball derivatives could potentially be used for a wide variety of medical applications, including HIV protease inhibition, DNA photoclevage, antibacterial activity, and photocytotoxicity for cancer treatment (10).The interaction of water with hydrophobic surfaces is responsible for many biological processes, such as protein folding, substrate binding and biological self-assembly of micelles, lyotropic mesophases, and lipid membranes. The molecular surface of proteins can have extended hydrophobic patches, so that buckyballs, graphite surfaces, and carbon nanotubes provide model systems for study of water molecules near large hydrophobic surfaces. An accurate description of interactions between water and its surrounding environment is essential for understanding and simulating such processes. Molecular dynamics (MD) simulations are used to study the behavior of water molecules next to hydrophobic surfaces at atomic detail and subpicosecond time resolution. The hydration structure of nonpolar solutes of varying size has been studied extensively in the past (11-22) using empirical force fields. Work from our lab has used empirical potential energy functions with popular water models to model the effect of a single molecule of benzene, cyclohexane (18, 21), methane, and C 60 (22) on the structural details of water around these solutes. All these studies used force fields with nonpolarizable fixed point charge water models and analyzed water structure with a low-sensitivity method unable to detect the effect of solute surface "roughness" on water structure.Polarization, which allows the ef...

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“…The value of λ was used to vary the surface energy gradient of the CNT [36]; it was greater than zero in the present simulations. It has been shown that the effective C-C interaction energy (ε C,C ) can be tuned by applying a dc or ac electric field [33,34,36] or using different chemical modifications [35,37,38]. The interaction energy (binding energy) between the water molecules and the CNT wall is much stronger with the increase of surface energy gradient [43].…”

Section: System and Methodsmentioning

confidence: 99%

“…A surface energy gradient was applied along the z-axis direction of the CNT. In reality, this can be altered through chemical modification or a dc or ac electric field [33][34][35][36][37][38]. For each set, after initially equilibrating the system at a specific temperature (200, 300, or 330 K) assuming a uniform surface energy along the CNT, the water nanodroplet was kept at 5 nm from the left end of the CNT.…”

Section: System and Methodsmentioning

confidence: 99%

Unidirectional motion of a water nanodroplet subjected to a surface energy gradient

Kou

Mei

et al. 2012

Phys. Rev. E

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We perform molecular dynamics simulations to demonstrate that when a nanodroplet is confined inside a carbon nanotube (CNT), unidirectional motion can be created by a nonzero surface energy gradient. It is found that the water nanodroplet moves along the direction of increasing surface energy. The transportation efficiency of the water nanodroplet is found to be dependent on the surface energy gradient; environmental temperature; and the flexibility, diameter, and defectiveness of the CNT. It is shown that higher surface energy gradient, the smaller diameter of the CNT, and fewer defects promote higher transportation efficiency. However, when the temperature is too high or too low, the water transport across the CNT is impeded. Except for the initial stage at the relatively low environmental temperature, higher flexibility of the CNT wall reduces the transportation efficiency. It is also found that the hydrogen bonds of water molecules play a role in the dynamic acceleration process with a wavelike feature. The present work provides insight for the development of CNT devices for applications such as drug delivery, nanopumps, chemical process control, and molecular medicine.

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Computation of the static polarizabilities of multi-wall carbon nanotubes and fullerites using a Gaussian regularized point dipole interaction model

Cited by 38 publications

References 69 publications

Tunable Core Size of Carbon Nanoscrolls

Tunable Core Size of Carbon Nanoscrolls

Remarkable patterns of surface water ordering around polarized buckminsterfullerene

Unidirectional motion of a water nanodroplet subjected to a surface energy gradient

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