Thermo- and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles

• Agata Siarkowska,
• Miłosz Chychłowski,
• Daniel Budaszewski,
• Bartłomiej Jankiewicz,
• Bartosz Bartosewicz and
• Tomasz R. Woliński

Beilstein J. Nanotechnol. 2017, 8, 2790–2801, doi:10.3762/bjnano.8.278

• would be negligible due to the size of the Au NP dopants (about 6 nm) as well as their distribution in microcapillaries of the PCF. However, the reported noticeable ionization was for NPs of size larger than 50 nm, where there could be an increased charge density at the surface of the NPs, affecting the

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• transferred to various solid substrates [100]. In a similar study, the exchange of citrate ligands by thioglycolic acid (Figure 2) allowed the authors to reduce the surface charge density, manipulate Coulomb repulsion between the particles, and initiate agglomeration in solution. Appropriate particle charges

Au₅₅, a stable glassy cluster: results of ab initio calculations

• Dieter Vollath,
• David Holec and
• Franz Dieter Fischer

Beilstein J. Nanotechnol. 2017, 8, 2221–2229, doi:10.3762/bjnano.8.222

• the atoms leads to an increased surface energy for smaller particles. Holec et al. [25] suggested resolving this situation by defining the cluster surface area as a convex hull of an electronic charge density higher than a certain constant “cut-off” value. The surface area a per cluster as a function

• of the “cut-off” charge density q is depicted in Figure 7. Approximating the cluster with a sphere of equal surface allows for calculating the cluster radius r as a function of the “cut-off” charge density. This is displayed in Figure 8. Using the density of bulk gold (ρ = 1.933 × 104 kg·m−3) as a

• . Both values are marked in Figure 8. The dependence of the cluster radius on the logarithm of the cut-off charge density q is linear: In Equation 6, the cluster radius rAu55 is given in meters and the cut-off charge density q in e·nm−3. This relation describes the dependency of the cluster radius on the

Effect of the fluorination technique on the surface-fluorination patterning of double-walled carbon nanotubes

• Lyubov G. Bulusheva,
• Yuliya V. Fedoseeva,
• Emmanuel Flahaut,
• Jérémy Rio,
• Christopher P. Ewels,
• Victor O. Koroteev,
• Gregory Van Lier,
• Denis V. Vyalikh and
• Alexander V. Okotrub

Beilstein J. Nanotechnol. 2017, 8, 1688–1698, doi:10.3762/bjnano.8.169

• with the graphene surface was studied using the DFT code AIMPRO [57][58][59] by fitting the charge density to plane waves with an energy cutoff of 300 Ha. Relativistic pseudopotentials generated by Hartwigsen, Goedecker and Hutter [60] were used. Correspondingly, 38, 44, and 28 independent Gaussian

The effect of the electrical double layer on hydrodynamic lubrication: a non-monotonic trend with increasing zeta potential

• Dalei Jing,
• Yunlu Pan and
• Xiaoming Wang

Beilstein J. Nanotechnol. 2017, 8, 1515–1522, doi:10.3762/bjnano.8.152

• conduction current, Iw is the sliding-wall-induced current, ρe = ce(n+−n−) is the local net ionic charge density within the EDL, λave is the average bulk electrical conductivity of the lubricant, λs is the surface electrical conductivity of the lubricant that is neglected here, and σ = −εε0(dφ/dz)z=0 is the

• surface charge density at the lower bearing surface. Based on the zero net current in the steady state, the electrical field strength Ex can be given as, Based on the previous studies, the bulk electrical conductivity of the lubricant under the influence of the EDL increases with the increasing absolute

• absolute value of the zeta potential. That is, the electrical potential shows a faster reduction. The mechanism for this phenomenon is described as follows. For the case of the zeta potential with a larger absolute value, there is a larger surface charge density at the bearing surface–lubricant interface

Two-dimensional silicon and carbon monochalcogenides with the structure of phosphorene

• Dario Rocca,
• Ali Abboud,
• Ganapathy Vaitheeswaran and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2017, 8, 1338–1344, doi:10.3762/bjnano.8.135

• concerning effective masses. To better understand the ionic character of the bonds involved in the new materials we have carried out an analysis of the PBE charge density based on the theory of Bader [37] as implemented by Henkelman et al. [38]. Since silicon has a low electronegativity we found that this

CVD transfer-free graphene for sensing applications

• Chiara Schiattarella,
• Sten Vollebregt,
• Tiziana Polichetti,
• Brigida Alfano,
• Ettore Massera,
• Maria Lucia Miglietta,
• Girolamo Di Francia and
• Pasqualina Maria Sarro

Beilstein J. Nanotechnol. 2017, 8, 1015–1022, doi:10.3762/bjnano.8.102

• analyte molecules, they have been assimilated as punctual impurities in the crystal lattice. Herein the Maxwell–Boltzmann approximation for the statistical description of charge carriers can be justified by virtue of the semi-classical regime of the system, with low induced charge density, of the order of

Near-field surface plasmon field enhancement induced by rippled surfaces

• Mario D’Acunto,
• Francesco Fuso,
• Ruggero Micheletto,
• Makoto Naruse,
• Francesco Tantussi and
• Maria Allegrini

Beilstein J. Nanotechnol. 2017, 8, 956–967, doi:10.3762/bjnano.8.97

• ., it is ruled by the geometrical anisotropy. We can say that the applied polarization of the electric field drives the plasmon resonance to be a geometrical polarization. Since the hot spots are strongly dependent on the charge density fluctuations due to rippled surfaces, the effect of the incident

• field enhancement. This is clearly a nonlinear effect where the surface geometry is able to confine charge on the walls of a single gap, simultaneously depleting the charge density from the surrounding gaps. Such a nonlinear effect is depicted in Figure 4. We consider a profile extracted from a rippled

Graphene functionalised by laser-ablated V₂O₅ for a highly sensitive NH₃ sensor

• Margus Kodu,
• Artjom Berholts,
• Tauno Kahro,
• Mati Kook,
• Peeter Ritslaid,
• Helina Seemen,
• Tea Avarmaa,
• Harry Alles and
• Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

• chemical bonding in platinum–graphene systems were observed when Pt nanoclusters were chemically bonded to point defects of graphene sheets. Furthermore, the adsorption of an O2 molecule onto a platinum nanocluster which was chemically bound to graphene resulted in a large influence on the charge density

Template-controlled piezoactivity of ZnO thin films grown via a bioinspired approach

• Nina J. Blumenstein,
• Fabian Streb,
• Stefan Walheim,
• Thomas Schimmel,
• Zaklina Burghard and
• Joachim Bill

Beilstein J. Nanotechnol. 2017, 8, 296–303, doi:10.3762/bjnano.8.32

• of tobacco mosaic viruses) on the mineralization processes of ZnO films has been investigated and an extraordinary high degree of orientation was observed. In this study, we elucidate the influence of the negative charge density of two non-piezoelectric templates on the deposition of ZnO films from

• templates. The negative surface charge of the sulfonate-functional groups of the PEL (−115 mV [40]) is high enough to homogeneously attract the dipolar ZnO particles from solution. The result is a closed film even at low numbers of deposition cycles. In contrast, the negative charge density of the

Impact of contact resistance on the electrical properties of MoS₂ transistors at practical operating temperatures

• Filippo Giannazzo,
• Gabriele Fisichella,
• Aurora Piazza,
• Salvatore Di Franco,
• Giuseppe Greco,
• Simonpietro Agnello and
• Fabrizio Roccaforte

Beilstein J. Nanotechnol. 2017, 8, 254–263, doi:10.3762/bjnano.8.28

• , cm−3). According to this expression a low value of VFB,id slightly varying with the T (from −0.35 V at 298 K to −0.42 V at 273 K) would be expected for our device. The negative shift of the experimental VFB with respect to VFB,id can be accounted for by the presence of a net positive charge density

Modelling of ‘sub-atomic’ contrast resulting from back-bonding on Si(111)-7×7

• Adam Sweetman,
• Samuel P. Jarvis and
• Mohammad A. Rashid

Beilstein J. Nanotechnol. 2016, 7, 937–945, doi:10.3762/bjnano.7.85

• closely reflect the force and/or charge density associated with the molecule. In Figure 3 we compare constant height force, and Δf images acquired with different oscillation amplitudes, at different tip–sample separations. Intriguingly, the triangular shape of the adatoms is more pronounced in the force

• interpretation of features of this type requires full ab-initio modelling of the combined tip–sample system, with full consideration of the combined charge density, and the relaxation of the atomic positions, in the tip–sample junction. Left column: Experimental constant height Δf images at decreasing tip–sample

Microscopic characterization of Fe nanoparticles formed on SrTiO₃(001) and SrTiO₃(110) surfaces

• Miyoko Tanaka

Beilstein J. Nanotechnol. 2016, 7, 817–824, doi:10.3762/bjnano.7.73

• nuclei for subsequent nanoparticle growth. Adjacent nuclei growing independently may merge and grow into a larger nanoparticle with a non-equilibrium interface. Charge effects should also be considered [62][63]. Both STO(001) and STO(110) surfaces could exhibit variations of charge density associated

First-principles study of the structure of water layers on flat and stepped Pb electrodes

• Xiaohang Lin,
• Ferdinand Evers and
• Axel Groß

Beilstein J. Nanotechnol. 2016, 7, 533–543, doi:10.3762/bjnano.7.47

• make the water–water interaction stronger [15]. In order to understand the differences between the water adsorption on the terraces and the steps, we have determined the charge density difference upon water adsorption on Pb(100) and Pb(511) (Figure 4) which corresponds to the adsorption-induced charge

• terrace atoms, as confirmed by an analysis of the charge density difference upon water adsorption. The thermal stability of the water layers has been addressed by performing ab initio molecular dynamics simulations at a temperature of 140 K. The minimum-energy structure of the water layers on Pb(111) and

• ) (a), Pb(511) (b) and Pb(711) (c). Isosurface plots of charge-density differences upon water adsorption on a) Pb(100) and b) Pb(511). The plotted isosurfaces correspond to charge density with an absolute value of 0.006 e/Å2. Charge accumulation, i.e., an increase in the electron density, is plotted in

Charge and heat transport in soft nanosystems in the presence of time-dependent perturbations

• Alberto Nocera,
• Carmine Antonio Perroni,
• Vincenzo Marigliano Ramaglia and
• Vittorio Cataudella

Beilstein J. Nanotechnol. 2016, 7, 439–464, doi:10.3762/bjnano.7.39

Invariance of molecular charge transport upon changes of extended molecule size and several related issues

• Ioan Bâldea

Beilstein J. Nanotechnol. 2016, 7, 418–431, doi:10.3762/bjnano.7.37

• charge density at the ends of the extended molecule computed within the WBL does not properly evolve into that of the bulk electrodes. The rather general model Hamiltonian of Equation 9 does satisfy these conditions. Condition (i) is satisfied because the electrodes’ parameters (on-site energies μL,R and

Influence of calcium on ceramide-1-phosphate monolayers

• Joana S. L. Oliveira,
• Gerald Brezesinski,
• Alexandra Hill and
• Arne Gericke

Beilstein J. Nanotechnol. 2016, 7, 236–245, doi:10.3762/bjnano.7.22

• a condensed monolayer, while at pH 7.2 the electrostatic repulsion of the negatively charged phosphomonoester head groups becomes more important and the monolayer is in a less solid-like state. Also at pH 7.2, the monolayer has a higher charge density than on water. They also determined the pKa2 in

Mismatch detection in DNA monolayers by atomic force microscopy and electrochemical impedance spectroscopy

• Maryse D. Nkoua Ngavouka,
• Pietro Capaldo,
• Elena Ambrosetti,
• Giacinto Scoles,
• Loredana Casalis and
• Pietro Parisse

Beilstein J. Nanotechnol. 2016, 7, 220–227, doi:10.3762/bjnano.7.20

• capacitance at the interface, due to a combination of height changes, displacement of water molecules upon binding of new strands, and rearrangement of charge density, bringing to a new value for the capacitance, CdsDNA [36]. Our device can follow the variation of capacitance in real time, allowing for the

• capacitance plateau, whereas AFM was not able to directly detect a height difference. Indeed, the changes of capacitance at the functionalized electrode are the results of a combination of changes of height in the molecular case and rearrangement of charge density. The distortions on the DNA structure due to

• of the DNA layer, the other more sensitive to its charge density) let us conclude that the structural deformations related to a single mismatch have a strong influence on the charge distribution only, leaving the molecular structure not significantly affected. Schematics of the atomic force

3D solid supported inter-polyelectrolyte complexes obtained by the alternate deposition of poly(diallyldimethylammonium chloride) and poly(sodium 4-styrenesulfonate)

• Eduardo Guzmán,
• Armando Maestro,
• Sara Llamas,
• Jesús Álvarez-Rodríguez,
• Francisco Ortega,
• Ángel Maroto-Valiente and
• Ramón G. Rubio

Beilstein J. Nanotechnol. 2016, 7, 197–208, doi:10.3762/bjnano.7.18

• their role during film formation is critical for controlling the structure and physicochemical properties of the films [13]. Among the most relevant variables are the charge density of the molecules, the concentration of the solution used, ionic strength, solvent quality for the molecules, pH, and

• polyelectrolyte occurs until a certain degree of charge inversion is reached, independently of the assembly conditions. This is explained considering that the increase of the ionic strength reduces the effective charge density of the polyelectrolyte multilayers, thus the overcompensation threshold is reached for

Charge injection and transport properties of an organic light-emitting diode

• Peter Juhasz,
• Juraj Nevrela,
• Michal Micjan,
• Miroslav Novota,
• Jan Uhrik,
• Lubica Stuchlikova,
• Jan Jakabovic,
• Ladislav Harmatha and
• Martin Weis

Beilstein J. Nanotechnol. 2016, 7, 47–52, doi:10.3762/bjnano.7.5

• efficacy (60–70 lm/W), which is the current benchmark for novel light sources [4]. Organic semiconductors have zero doping level and very low intrinsic charge density, therefore all charges in OLED device are injected from the electrodes. As a result, the energy band diagram analysis plays a key role in

• characteristics. At voltages below 2 V the low charge injection region can be recognized, since the current density J follows applied voltage bias V linearly, where e·n is the charge density (e: elementary charge, n charge carrier density), μeff is the effective charge mobility, and L the organic film thickness

• -relaxation processes in OLED devices. Charge injection/transport phenomena are thermally activated processes that follow the Boltzmann distribution. The Arrhenius plots of conductivities have been used to evaluate activation energies, as shown in Figure 5a. Since the conductivity G is affected by charge

pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• charged substrates. The most common and therefore best investigated multilayer build-up involves two oppositely charged polyelectrolytes. Weak polyelectrolytes, such as polyacrylic acid (PAA), with a pH-dependent charge density can be used to add pH-tunable properties to the nanoparticle surface to which

• , which could be attributed to successful adsorption of the cationic PEI layer. pH-Sensitivity of the PAA layer in dependence on the adsorption pH value PAA, as a weak polyelectrolyte with a charge density depending on pH, can be easily adsorbed onto positively charged substrates, such as PLGA

• nanoparticles with an adsorbed layer of PEI. In order to investigate the effect of the linear charge density of adsorbing chains on the resulting layer properties, PAA from solutions adjusted to three different pH values, respectively, was adsorbed to PLGA–PEI nanoparticles. Regarding the ionization degree, the

Electroviscous effect on fluid drag in a microchannel with large zeta potential

• Dalei Jing and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2015, 6, 2207–2216, doi:10.3762/bjnano.6.226

• molecular dynamics (MD) simulations. They found that a large surface charge density results in a smaller slip. Jing and Bhushan [13] experimentally studied the coupling relationship between the surface charge and the slip of a smooth and hydrophobic octadecyltrichlorosilane (OTS) sample immersed in

• deionized water and saline solutions using the colloidal probe atomic force microscopy technique. They also found that an increasing surface charge density results in a decreasing slip length. Thus, the coupling between the surface charge and slip should be considered when study the combined effect of EDL

• flow in the microchannel, dp/dx is the driving pressure gradient, ρe = ze(n+ − n−) is the local net charge density in the EDL, and Ex is the electrical field strength. The modified Navier–Stokes equation gives the velocity boundary conditions where b is the charge-dependent slip length. The effect of

Mapping bound plasmon propagation on a nanoscale stripe waveguide using quantum dots: influence of spacer layer thickness

• Chamanei S. Perera,
• Alison M. Funston,
• Han-Hao Cheng and
• Kristy C. Vernon

Beilstein J. Nanotechnol. 2015, 6, 2046–2051, doi:10.3762/bjnano.6.208

• are a coherent oscillation of electrons in a metal [1]. Loosely bound electrons can combine with incoming photons and propagate along the metal/dielectric interface. These charge density waves create a strong near-field [1]. There is increasing demand for high speed data communication as well as

Transformations of PTCDA structures on rutile TiO₂ induced by thermal annealing and intermolecular forces

• Szymon Godlewski,
• Jakub S. Prauzner-Bechcicki,
• Thilo Glatzel,
• Ernst Meyer and
• Marek Szymoński

Beilstein J. Nanotechnol. 2015, 6, 1498–1507, doi:10.3762/bjnano.6.155

• ) should contribute mostly to the STM appearance when imaging of empty states is performed. The charge density contour of the PTCDA LUMO orbital comprises 14 lobes located symmetrically with respect to the longer molecular axis, where the orbital wave function changes its sign. As a result, the charge

• density in the proximity of the longer axis is very low, and thus, that area does not contribute significantly to the tunnelling process. In our high-resolution measurements, a single PTCDA molecule appears as two lobes with a clear depression between them. Considering the LUMO contour, the depression

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• charge density and the material structure, the concept of bending rigid electronic bands at an interface can break down because of the emergence of new types of quasiparticles and order [32]. The nature of polaron quasiparticles may change during their interfacial transfer because of the variation of the