Influence of Klein edges on Phononic and electronic transport in circular graphene devices.

We study the electron and phonon transport coefficients of graphene disks and rings in the presence of Klein edges. We examine the transport characteristics by changing of the outer and inner radius using the non-equilibrium Green's function approach. We find that the effect of the nanodisk radius is highly influenced by the Klein edges, such that at small radii, armchair Klein edges can help preserve the electronic transport coefficient from suppression, while zigzag Klein edges significantly suppress the transmission spectrum, highlighting the importance of the edge atom sublattice.

Thermal rectification in novel two-dimensional hybrid graphene/BCN sheets: A molecular dynamics simulation.

The graphene-like monolayer of carbon, boron and nitrogen that maintains the native hexagonal atomic lattice (BCN), is a novel semiconductor with special thermal properties. Herein, with the aid of a non-equilibrium molecular dynamics approach (NEMD), we study phonon thermal rectification in a hybrid system of pure graphene and BCN (G-BCN) in various configurations under a series of positive and negative temperature gradients. We begin by investigating the relation of thermal rectification to sample's mean temperature, T, and the imposed temperature difference, ΔT, between the two heat baths at its ends.

Flexible thermoelectrics in crossed graphene/hBN composites.

Nanostructures exhibit unusual properties due to the dominance of quantum mechanical effects. In addition, the geometry of a nanostructure can have a strong influence on its physical properties. Using the tight-binding and force-constant approaches with the help of the non-equilibrium Green's function method, the transport and thermoelectric properties of cross-shaped (X-shaped) composite heterostructures are studied in two cases: Mixed graphene and h-BN (HETX-CBN) and all graphene (HETX-C) cross-shaped structures.

Tuning phononic and electronic contributions of thermoelectric in defected S-shape graphene nanoribbons.

Thermoelectrics as a way to use waste heat, is essential in electronic industries, but its low performance at operational temperatures makes it inappropriate in practical applications. Tailoring graphene can change its properties. In this work, we are interested in studying the transport properties of S-shape graphene structures with the single vacancy (SV) and double vacancy (DV) models.

Vacancy tuned thermoelectric properties and high spin filtering performance in graphene/silicene heterostructures.

The main contribution of this paper is to study the spin caloritronic effects in defected graphene/silicene nanoribbon (GSNR) junctions. Each step-like GSNR is subjected to the ferromagnetic exchange and local external electric fields, and their responses are determined using the nonequilibrium Green's function (NEGF) approach. To further study the thermoelectric (TE) properties of the GSNRs, three defect arrangements of divacancies (DVs) are also considered for a larger system, and their responses are re-evaluated.

Effect of graphene and carbon-nitride nanofillers on the thermal transport properties of polymer nanocomposites: A combined molecular dynamics and finite element study.

Low thermal conductivity of polymers, which is one of the considerable drawbacks of commonly used composite structures, has been the focus of many researchers aiming to achieve high-performance polymer-based nanocomposites through the inclusion of highly thermally conductive fillers inside the polymer matrices. Thus, in the present study, a multiscale scheme using nonequilibrium molecular dynamics and the finite element method is developed to explore the impact of different nanosized fillers (carbon-nitride and graphene) on the effective thermal conductivity of polyethylene-based nanocomposites. We show that the thermal conductivity of amorphous polyethylene at room temperature using the reactive bond order interatomic potential is nearly 0.

Predicting the new carbon nanocages, fullerynes: a DFT study.

In this study, based on density functional theory, we propose a new branch of pseudo-fullerenes which contain triple bonds with sp hybridization. We call these new nanostructures fullerynes, according to IUPAC. We present four samples with the chemical formula of CH, and the structures derived from fulleranes.

Pure thermal spin current and perfect spin-filtering with negative differential thermoelectric resistance induced by proximity effect in graphene/silicene junctions.

The spin-dependent Seebeck effect (SDSE) and thermal spin-filtering effect (SFE) are now considered as the essential aspects of the spin caloritronics, which can efficiently explore the relationships between the spin and heat transport in the materials. However, there is still a challenge to get a thermally-induced spin current with no thermal electron current. This paper aims to numerically investigate the spin-dependent transport properties in hybrid graphene/silicene nanoribbons (GSNRs), using the nonequilibrium Green's function method.

Hydration effects and negative dielectric constant of nano-confined water between cation intercalated MXenes.

Using electrochemical methods a profound enhancement of the capacitance of electric double layer capacitor electrodes was reported when water molecules are strongly confined into the two-dimensional slits of titanium carbide MXene nanosheets [A. Sugahara et al., Nat.

Thermal rectification and interfacial thermal resistance in hybrid pillared-graphene and graphene: a molecular dynamics and continuum approach.

We investigate thermal rectification and thermal resistance in a hybrid pillared-graphene and graphene (PGG) system by both molecular dynamics (MD) simulation and a continuum model. First, the thermal conductivity of both pillared-graphene and graphene is calculated by employing MD simulation and Fourier's law. Our results show that the thermal conductivity of the pillared-graphene is much smaller than that of graphene by one order of magnitude.

Topological and transport properties of graphene-based nanojunctions subjected to a magnetic field.

We study the topological properties of finite-size S-shaped graphene junctions with distinctive edge features subjected to the perpendicular magnetic field, using the tight-binding model. The quantum confinement and edge effects induced by the specific junction give rise to significant modifications in the Hofstadter spectra of the bent flakes, when compared to those of their perfect forms. Moreover, the results show that in absence of a magnetic field, the sharpest zigzag-edged corners support the edge states rather than the others, but the magnetic field leads to the localization of the edge states along the whole perimeter of the flakes.

Thermal transport across grain boundaries in polycrystalline silicene: A multiscale modeling.

During the fabrication process of large scale silicene, through common chemical vapor deposition (CVD) technique, polycrystalline films are quite likely to be produced, and the existence of Kapitza thermal resistance along grain boundaries could result in substantial changes of their thermal properties. In the present study, the thermal transport along polycrystalline silicene was evaluated by performing a multiscale method. Non-equilibrium molecular dynamics simulations (NEMD) was carried out to assess the interfacial thermal resistance of various constructed grain boundaries in silicene.

Vesicle-like structure of lipid-based nanoparticles as drug delivery system revealed by molecular dynamics simulations.

Lipid-based drug delivery systems are considered as promising vehicles for hydrophobic drug compounds. Lipid distribution within the droplet can affect drug loading capacity in these carriers. However, it is extremely challenging to determine the nanostructure within these carriers through the implementation of the direct experimental methods due to the ultrafine size.

Highly tunable charge and spin transport in silicene junctions: phase transitions and half-metallic states.

We report peculiar charge and spin transport properties in S-shaped silicene junctions with the Kane-Mele tight-binding model. In this work, we investigate the effects of electric and exchange fields on the charge and spin transport properties. Our results show that by applying a perpendicular electric field, metal-semiconductor and also semimetal-semiconductor phase transitions occur in our systems.

Synthesis and characterization of dextran coated magnetite nanoparticles for diagnostics and therapy.

Introduction: Expansion of efficacious theranostic systems is of pivotal significance for medicine and human healthcare. Magnetic nanoparticles (MNPs) are known as drug delivery system and magnetic resonance imaging (MRI) contrast agent. MNPs as drug carriers have attracted significant attention because of the delivery of drugs loaded onto MNPs to solid tumors, maintaining them in the target site by an external electromagnetic field, and subsequently releasing drugs in a controlled manner.

The impact of polymer coatings on magnetite nanoparticles performance as MRI contrast agents: a comparative study.

Background: Superparamagnetic iron oxide nanoparticles (SPIONs) are the most commonly used negative MRI contrast agent which affect the transverse (T2) relaxation time. The aim of the present study was to investigate the impact of various polymeric coatings on the performance of magnetite nanoparticles as MRI contrast agents.

Methods: Ferrofluids based on magnetite (Fe3O4) nanoparticles (SPIONs) were synthesized via chemical co-precipitation method and coated with different biocompatible polymer coatings including mPEG-PCL, chitosan and dextran.