Fullerenes
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. ESTRUTURAS DE FULERENOS: ESTABELECENDO INTERFACES NO ENSINO DE MATEMÁTICA E QUÍMICA EM NÍVEL SUPERIOR
The objective of this paper is to study fullerene geometry properties and attempt to stablish a dialogue between the teaching of mathematics and chemistry concepts using hands-on cardboard geometric models, in classroom, in order to facilitate the understanding of fullerene structures. This approach to the study of such molecules represents a unique opportun
Quím. Nova. Publicado em: 2017-09
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2. Eixo quinário: um elemento de simetria presente em moléculas e quasi-cristais - um experimento didático em cristalografia
Axis of quinary symmetry occur in molecular symmetry, as in the case of fullerenes, and in crystalline symmetry, in the quasicrystals. Minerals with pentagonal faces do not have this element of symmetry, as the pyrite (FeS2) which shows a ridge that is different from the other ones, in any face of the crystal. The purpose of this paper is to demonstrate conc
Química Nova. Publicado em: 2010
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3. Termodinâmica de sistemas fullerênicos em soluções / Thermodynamic systems fullerenic solutions
In this work, we present a computational study of the solvation process of the C60 fullerene and its hydroxylated derivate, the fullerenol C60(OH)24, in aqueous environment and organic solvents, using classical molecular dynamics simulations. Diverse sets of parameters to the Lennard-Jones interaction potential have been utilized in simulations of fullerenes
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/09/2009
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4. How can encapsulated C60 fullerenes escape from a carbon nanotube?: A molecular dynamics simulation answer
This work aim is to determine how a C60 fullerene, encapsulated into a (10,10) carbon nanotube, can be ballistically expelled from it by using a colliding capsule. Initially, the C60 fullerene is positioned at rest inside the nanotube. The capsule, also starting from rest but outside of the nanotube, is put in a position such that it can be trapped towards t
Brazilian Journal of Physics. Publicado em: 2008-03
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5. Effect of triplet encapsulated atoms in [60] fullerenes: a theoretical analysis
The present investigation reports on the interaction of the C/O triplet atoms inside of the [60] fullerene (C60) species with small polar molecules (H²O, CH³OH, HF, NH³) using Density Functional Theory (DFT) calculations. The calculations show that in all the computed cases the encapuslated complexes with the molecules are more stable than without interna
Eclética Química. Publicado em: 2008
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6. Purificação e caracterização de nanotubos de carbono produzidos pelo método de descarga em arco elétrico
The objective of this work was to study the purification of a sample of commercial carbon nanotubes (CNTs) produced by the Carbolex arc-discharge method using the catalyst mixture Ni/Y (4/1 at. %). Another objective of this work was to investigate an alternative functionalization route for the introduction of hydroxyl groups (-OH) onto CNT sidewalls and to e
Publicado em: 2008
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7. Estudo estrutural e eletronico de fulerenos e diamondoides encapsulados em nanotubos de carbono / Structural and electronical study of encapsulated fullerenes and diamondoids in carbon nanotubes
This work presents a theoretical study of carbon nanostructures with great interest in nanoscience world. It is about the structural, electronic and mechanical study of hybrid structures that result from encapsulation of carbon molecules (fullerenes and diamondoids) introduced inside carbon nanotubes. Using classical methods of molecular dynamics we performe
Publicado em: 2007
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8. Nanoestruturas formadas por redes orgânicas covalentes
In this work we apply first-principles calculations based on the Density Functional Theory (DFT) to investigate structural and electronic properties of covalent organic frameworks (COF s). These structures were recently obtained experimentally and constitute a new class of porous nanostructures composed only of light elements (H, C, B and O atoms). The coval
Publicado em: 2007
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9. "Propriedades estruturais e eletrônicas de heterofulerenos em superfícies" / Electronic and structural properties of heterofullerenes on surfaces
Neste trabalho, propomos o uso do átomo do silício da molécula C59Si como uma maneira possível de ancorar moléculas de fulerenos em uma superfície de silício, devido à formação de uma ligação forte com um dos átomos de silício da superfície. Consideramos uma superfície Si(100) monohidrogenada com um H removido de um dos átomos de silício da
Publicado em: 2006
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10. Sintese e caracterização de nanotubos e fulerenos nitrogenados gerados por arco aletrico
This thesis work aims to synthesize and to characterize structural and chemically nanotubes and fullerenes containing nitrogen. Both nanotubes and fullerenes syntheses were performed using an arc-discharge system filled with gaseous mixtures of He e N2. Electron microscopy samples analysis shows that N2 concentration inside the arc-discharge chamber influenc
Publicado em: 2004
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11. A bench arc-furnace facility for fullerene and single-wall nanotubes synthesis
A metallic-sample arc-furnace was modified to synthesize fullerenes and nanotubes. The (reversible) changes and the process for producing single-wall nanotubes (SWNTs) are described.
Química Nova. Publicado em: 2001-12
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12. Fullerenes: An extraterrestrial carbon carrier phase for noble gases
In this work, we report on the discovery of naturally occurring fullerenes (C60 to C400) in the Allende and Murchison meteorites and some sediment samples from the 65 million-year-old Cretaceous/Tertiary boundary layer (KTB). Unlike the other pure forms of carbon (diamond and graphite), fullerenes are extractable in an organic solvent (e.g., toluene or 1,2,4
The National Academy of Sciences.