Vibrational characterization of dinaphthylpolyynes: a model system for the study of end-capped sp carbon chains

From nanohole to ultralong straight nanochannel fabrication in graphene oxide with swift heavy ions

Porous architectures based on graphene oxide with precisely tailored nm-sized pores are attractive for biofluidic applications such as molecular sieving, DNA sequencing, and recognition-based sensing. However, the existing pore fabrication methods are complex, suffer from insufficient control over the pore density and uniformity, or are not scalable to large areas. Notably, creating vertical pores in multilayer films appears to be particularly difficult. Here, we show that uniform 6-7 nm-sized holes and straight, vertical nanochannels can be formed by simply irradiating graphene oxide (GO) films with high-energy heavy ions. Long penetration depths of energetic ions in combination with localized energy deposition and effective self-etching processes enable the creation of through pores even in 10 µm-thick GO films. This fully scalable fabrication provides a promising possibility for obtaining innovative GO track membranes.

Carbon sp chains in diamond nanocavities

We propose a new class of carbon allotropes obtained by combining linear sp carbon chains with sp3 bulk carbon. The structure of these crystalline carbon allotropes consists of sp chains inserted in cylindrical cavities periodically arranged in hexagonal diamond (lonsdaleite). We carry out a detailed computational analysis of the structural, electronic, and vibrational properties of a simple form in this class: a single C6 strand embedded in a nm-sized cavity. We obtain a metallic allotrope exhibiting characteristic high-frequency vibrations associated with the sp chain stretching modes, and characterized by long-time room-temperature stability. In addition, we suggest how numerous similar allotropes could be constructed within this class, that we call zayedenes, all characterized by comparable metallicity and high-frequency vibrations.

Novamene: A new class of carbon allotropes

We announce a new class of carbon allotropes. The basis of this new classification resides on the concept of combining hexagonal diamond (sp³ bonded carbon − lonsdaleite) and ring carbon (sp² bonded carbon − graphene). Since hexagonal diamond acts as an insulator and sp² bonded rings act as conductors, these predicted materials have potential applications for transistors and other electronic components. We describe the structure of a proposed series of carbon allotropes, novamene, and carry out a detailed computational analysis of the structural and electronic properties of the simplest compound in this class: the single-ring novamene. In addition, we suggest how hundreds of different allotropes of carbon could be constructed within this class.

Carbon-atom wires: 1-D systems with tunable properties

This review provides a discussion of the current state of research on linear carbon structures and related materials based on sp-hybridization of carbon atoms (polyynes and cumulenes). We show that such systems have widely tunable properties and thus represent an intriguing and mostly unexplored field for both fundamental and applied sciences. We discuss the rich interplay between the structural, vibrational, and electronic properties focusing on recent advances and the future perspectives of carbon-atom wires and novel hybrid sp-sp(2)-carbon architectures.

Mechanical properties of carbyne: experiment and simulations

The results of the high-field technique for obtaining and testing the carbyne strength in situ are presented. By using molecular dynamics simulation and ab initio calculations, a comprehensive analysis of the results is executed. High-field technique for experimental measurement of the carbyne strength in situ is briefly described. It is shown that the technique used gives a lower estimation for strength of carbyne, which equals 251 GPa at T = 77 K. This value is close to the strength 7.85 nN (250 GPa) of contact atomic bond between carbyne and graphene sheet, from which the monatomic chain is pulled. The strength of carbyne itself is determined by strength of an edge atomic bond and it is ≈ 12.35 nN (393 GPa) at T = 0 K. For carbynes containing more than 10 to 12 atoms, the coefficient of elasticity (k Y  = 145.40 nN) and the elastic modulus (Y = 4631 GPa) are ascertain.

Thermal formation of carbynes

We simulate the formation of sp carbon chains (carbynes) by thermal decomposition of sp(2) carbon heated by a hot discharge plasma, by means of tight-binding molecular dynamics. We obtain and analyze the total quantity of carbynes and their length distribution as a function of temperature and density.