Effect of Anderson localization on light emission from gold nanoparticle aggregates

• Mohamed H. Abdellatif,
• Marco Salerno,
• Gaser N. Abdelrasoul,
• Ioannis Liakos,
• Alice Scarpellini,
• Sergio Marras and
• Alberto Diaspro

Beilstein J. Nanotechnol. 2016, 7, 2013–2022, doi:10.3762/bjnano.7.192

• : where s is the interparticle distance and VT is the total interaction potential, which according to the classical model of DLVO theory [32][33] is made of is two parts [25]: where Velec is the electrostatic repulsion potential due to Coulomb force, and VVdW is the Van der Waals interaction potential

Influence of ambient humidity on the attachment ability of ladybird beetles (Coccinella septempunctata)

• Lars Heepe,
• Jonas O. Wolff and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1322–1329, doi:10.3762/bjnano.7.123

• affect the attachment ability in this case, since the contact is mediated by the tarsal secretion and not by a solid–solid contact. Coming back to the abovementioned mechanisms of capillary forces and/or changes in the effective short-range van der Waals interaction, which might influence the humidity

Correlative infrared nanospectroscopic and nanomechanical imaging of block copolymer microdomains

• Benjamin Pollard and
• Markus B. Raschke

Beilstein J. Nanotechnol. 2016, 7, 605–612, doi:10.3762/bjnano.7.53

• or capillary forces). It can reflect variations in the Hamaker constant of the van der Waals interaction, surface charges, or hydrophilicity [32]. It has been observed in PS-b-PMMA that PS preferentially adsorbs onto a gold surface compared to PMMA [33]. Thus, the higher attractive forces over PS

• relative humidity during the measurement (13%) indicate that we are operating near the threshold between attractive and repulsive regimes [30]. The delicate balance between repulsive capillary forces and overall van der Waals interaction could result in the finer variations across the PMMA microdomain. We

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

A simple and efficient quasi 3-dimensional viscoelastic model and software for simulation of tapping-mode atomic force microscopy

• Santiago D. Solares

Beilstein J. Nanotechnol. 2015, 6, 2233–2241, doi:10.3762/bjnano.6.229

• model via an equation similar to the Hamaker equation [12]. Thus, the contribution to the van der Waals forces for area element j is where V is a van der Waals ‘strength’ parameter in the code (see c-file in Supporting Information File 1) that adjusts the magnitude of the van der Waals interaction

• axis): as the tip indents deeper into the sample, new surface elements of increasingly larger area become active and contribute to the force curve (recall that the SLS contribution of each surface element is proportional to its area); (c) schematic of the greater van der Waals interaction for a tip

Dynamic force microscopy simulator (dForce): A tool for planning and understanding tapping and bimodal AFM experiments

• Horacio V. Guzman,
• Pablo D. Garcia and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2015, 6, 369–379, doi:10.3762/bjnano.6.36

• resulting expressions. van der Waals The van der Waals interaction between a sphere and a half-space is calculated by [46] where Rt is the tip radius, H is the Hamaker constant, d is the distance between the tip’s apex the sample surface and a0 is the intermolecular distance (0.165 nm). Derjaguin–Landau

Intake of silica nanoparticles by giant lipid vesicles: influence of particle size and thermodynamic membrane state

• Florian G. Strobl,
• Florian Seitz,
• Christoph Westerhausen,
• Armin Reller,
• Adriano A. Torrano,
• Christoph Bräuchle,
• Achim Wixforth and
• Matthias F. Schneider

Beilstein J. Nanotechnol. 2014, 5, 2468–2478, doi:10.3762/bjnano.5.256

• . The ζ-potential is inserted for the relevant surface potential, as also proposed in [33]. In Figure 4, gdl is plotted for ζ = −50 mV and l = 1.72 nm and εr = 79, corresponding to our experimental conditions. Additionally, an approximation for the non-retarded van der Waals interaction is given (see

• accumulate preferably into the gel phase of phase-separated GUVs. Both authors mention undulation forces as one possible reason for the observed effects. However, the typical strength of undulation forces is similar to that of the van der Waals interaction [40] and hence rather too weak to explain the

Two-dimensional and tubular structures of misfit compounds: Structural and electronic properties

• Tommy Lorenz,
• Jan-Ole Joswig and
• Gotthard Seifert

Beilstein J. Nanotechnol. 2014, 5, 2171–2178, doi:10.3762/bjnano.5.226

• shown in Figure 1b. In these cases, the TMX2 layers are held together by van der Waals forces, whereas the interaction between MX and TMX2 layers is based on van der Waals interaction and a charge transfer (CT) from MX to TMX2 [12]. Thus, misfit compounds do not only differ by stoichiometry, difference

• are bonded only by van der Waals interaction. This is one reason why it is possible to intercalate metal atoms within this van der Waals gap. Due to the fact that layered materials show exceptional lubricating properties originating in strong intra-layer, but weak inter-layer interactions, lubricating

Equilibrium states and stability of pre-tensioned adhesive tapes

• Carmine Putignano,
• Luciano Afferrante,
• Luigi Mangialardi and
• Giuseppe Carbone

Beilstein J. Nanotechnol. 2014, 5, 1725–1731, doi:10.3762/bjnano.5.182

• reproducing such properties in artificial bio-mimetic adhesives [1][2][3]. In nature, many adhesive systems consist of arrays of hierarchical hairs or setae, enabling large contact areas and hence high adhesion owing to the van der Waals interaction forces [4]. This morphology enables many insects, spiders

Direct observation of microcavitation in underwater adhesion of mushroom-shaped adhesive microstructure

• Lars Heepe,
• Alexander E. Kovalev and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 903–909, doi:10.3762/bjnano.5.103

• results we may consider the following two limiting cases in the underwater adhesion of MSAMS. In the first case, a thin water layer separates the glass–MSAMS contact. Then the van der Waals interaction strength, described by the Hamaker constant between glass and MSAMS, is expected to be reduced by about

Fibrillar adhesion with no clusterisation: Functional significance of material gradient along adhesive setae of insects

• Stanislav N. Gorb and
• Alexander E. Filippov

Beilstein J. Nanotechnol. 2014, 5, 837–845, doi:10.3762/bjnano.5.95

• accepted that majority of physical surfaces have scale-invariant spectrum C(q) = 1/qβ with exponent β ≈ 0.9. The amplitude of the numerical “surface” is taken to be comparable with the radius of van der Waals interaction A = r0. Soft parts of every fiber, which normally are physically thin and flexible

DNA origami deposition on native and passivated molybdenum disulfide substrates

• Xiaoning Zhang,
• Masudur Rahman,
• David Neff and
• Michael L. Norton

Beilstein J. Nanotechnol. 2014, 5, 501–506, doi:10.3762/bjnano.5.58

• ordered array. These results are of crucial importance, as they support the hypothesis that the van der Waals interaction between MoS2 and the DNA in the origami is of sufficient strength to destabilize the hydrogen bonds as well as the π–π stacking interactions in the relatively short duplex regions

• with the phosphate group of the DNA origami constructs, binding them to the surface through formation of salt bridges. Pre-adsorption of 1-pyrenemethylamine molecules serves to mask the MoS2 surface and to sufficiently reduce the van der Waals interaction between MoS2 and the double stranded DNA in the

• applications. In this work, the behavior of DNA origami structures on a MoS2 surface was studied for the first time. Our results revealed that DNA origami nanostructures are not stable when in direct contact with the MoS2 surface. This can be attributed to the van der Waals interaction between nucleobases and

Tensile properties of a boron/nitrogen-doped carbon nanotube–graphene hybrid structure

• Kang Xia,
• Haifei Zhan,
• Ye Wei and
• Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 329–336, doi:10.3762/bjnano.5.37

• deformation is found to result two dangling layers (upper and lower) that adhere to each other. This adhesive behavior is the reason for the residual stress, which is highlighted in Figure 7. With sufficient elongation, the dangling layers finally separate from each other by van der Waals interaction. The

The role of surface corrugation and tip oscillation in single-molecule manipulation with a non-contact atomic force microscope

• Christian Wagner,
• Norman Fournier,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 202–209, doi:10.3762/bjnano.5.22

• summed over the atoms constituting PTCDA. The surface is represented by a continuous plane that interacts with the individual atoms of PTCDA via the Pauli repulsion parameterized by an exponential potential that is proprotional to exp(−Apz) and the van der Waals interaction expressed as a potential

• proportional to z−3. We note here that the correct asymptotic behavior of the van der Waals interaction is (z − z0)−3, where z0 is the location of the van der Waals plane, usually z0 = (1/2) dlattice. However, as discussed in [24][25], this form is only valid for z > 5 Å while for z < 5 Å the van der Waals

• interaction is damped. We achieve this damping by letting z0 → 0. More details can be found in [24]. For simplicity it is assumed that PTCDA consists of only two types of atoms: the 26 backbone (all carbon plus the two anhydride oxygen atoms; hydrogen atom interaction is scaled by 0.25) and the four

Noise performance of frequency modulation Kelvin force microscopy

• Heinrich Diesinger,
• Dominique Deresmes and
• Thierry Mélin

Beilstein J. Nanotechnol. 2014, 5, 1–18, doi:10.3762/bjnano.5.1

• favorable to minimize the tip–sample distance since it deteriorates the lateral resolution. Setpoint Δf and Vmod should be chosen such that the topography feedback is still dominated by van-der-Waals interaction. However, the tip–sample separation cannot be made infinitely small by hardening the topography

• shows the tip in the attractive part of the van-der-Waals interaction. The force gradient in this field must not exceed the spring constant to avoid snap to contact. We take the attractive range of a Lennard-Jones type of potential The force gradient is proportional to the second derivative: To avoid

Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

• Sidney R. Cohen and
• Estelle Kalfon-Cohen

Beilstein J. Nanotechnol. 2013, 4, 815–833, doi:10.3762/bjnano.4.93

• water that is sufficient for increasing the capillary and possibly van der Waals interaction. Any additional adhesion will act to increase the hysteresis in the force–distance curve and thus complicate the application of simple mechanical models. In addition to these environmental effects, the

Ni nanocrystals on HOPG(0001): A scanning tunnelling microscope study

• Michael Marz,
• Keisuke Sagisaka and
• Daisuke Fujita

Beilstein J. Nanotechnol. 2013, 4, 406–417, doi:10.3762/bjnano.4.48

• bias at which the pick-up takes place is quite small, we can conclude that the whole process is dominated by the van der Waals interaction: In Figure 9 the dominant forces involved in the pick-up process are plotted: the adhesive force with a constant value of Fa = −4.36 nN (solid black line) and the

Influence of the solvent on the stability of bis(terpyridine) structures on graphite

• Daniela Künzel and
• Axel Groß

Beilstein J. Nanotechnol. 2013, 4, 269–277, doi:10.3762/bjnano.4.29

• interaction energy. These findings can be rationalized fairly easily. BTP interacts strongly with the graphite surface via van der Waals interaction [12], thus the adsorption under vacuum conditions leads to a relatively high gain in energy. BTP also interacts strongly with the TCB solvent, which is why it

Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates

• Gabriele Fisichella,
• Salvatore Di Franco,
• Patrick Fiorenza,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Cristina Tudisco,
• Guido G. Condorelli,
• Nicolò Piluso,
• Noemi Spartà,
• Stella Lo Verso,
• Corrado Accardi,
• Cristina Tringali,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2013, 4, 234–242, doi:10.3762/bjnano.4.24

• and SiO2 and graphene and PEN. In fact, a van der Waals interaction occurs between graphene and SiO2, whereas it cannot be excluded that other kind of bonds occur locally between graphene and the polymeric substrate, leading to a partial sp3 hybridization of graphene C atoms and, hence, to a local

Graphite, graphene on SiC, and graphene nanoribbons: Calculated images with a numerical FM-AFM

• Fabien Castanié,
• Laurent Nony,
• Sébastien Gauthier and
• Xavier Bouju

Beilstein J. Nanotechnol. 2012, 3, 301–311, doi:10.3762/bjnano.3.34

• , germanium, etc). Recent improvements of this potential [103] do not modify the results presented below. In the case of graphite, the van der Waals interaction between two layers is described by a standard Lennard-Jones potential: with ε = 0.011 eV and σ = 3.2963 Å. Results and Discussion Graphite surface

Transmission eigenvalue distributions in highly conductive molecular junctions

• Justin P. Bergfield,
• Joshua D. Barr and
• Charles A. Stafford

Beilstein J. Nanotechnol. 2012, 3, 40–51, doi:10.3762/bjnano.3.5

• an attractive interaction between a molecule and a metal surface (van der Waals interaction). By diagonalizing the molecular Hamiltonian with and without the effects of screening included in Unm, it is possible to determine the van der Waals interaction at arbitrary temperature between a neutral

Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group

• Einat Tirosh,
• Enrico Benassi,
• Silvio Pipolo,
• Marcel Mayor,
• Michal Valášek,
• Veronica Frydman,
• Stefano Corni and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2011, 2, 834–844, doi:10.3762/bjnano.2.93

• approximately estimate the role of Au, in particular of the Au–SAM van der Waals interaction, further work is needed to properly assess the choices specific to these simulations, such as the Au–SAM force field, the arrangement of the SAM with respect to the Au lattice and the role of Au mobility. All

STM study on the self-assembly of oligothiophene-based organic semiconductors

• Elena Mena-Osteritz,
• Marta Urdanpilleta,
• Erwaa El-Hosseiny,
• Berndt Koslowski,
• Paul Ziemann and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 802–808, doi:10.3762/bjnano.2.88

• oligo- and polythiophenes and can be explained by van der Waals interaction driven full interdigitation of the alkyl chains of two opposite molecules in their all-trans conformation in different rows [9][10][11][12][18]. Theoretical calculations on a group of four molecules, excluding the substrate

How to remove the influence of trace water from the absorption spectra of SWNTs dispersed in ionic liquids

• Juan Yang,
• Daqi Zhang and
• Yan Li

Beilstein J. Nanotechnol. 2011, 2, 653–658, doi:10.3762/bjnano.2.69

• structure of the SWNTs is not damaged. Moreover, a previous study [18] has shown that the electronic structure and properties of SWNTs are retained since there is no strong interaction, but only weak van der Waals interaction, between SWNTs and ILs. Therefore, imidazolium-based ILs are ideal media for the

Distinguishing magnetic and electrostatic interactions by a Kelvin probe force microscopy–magnetic force microscopy combination

• Miriam Jaafar,
• Oscar Iglesias-Freire,
• Luis Serrano-Ramón,
• Manuel Ricardo Ibarra,
• Jose Maria de Teresa and
• Agustina Asenjo

Beilstein J. Nanotechnol. 2011, 2, 552–560, doi:10.3762/bjnano.2.59

• of an oxide layer 2 nm thick and a contact potential between tip and sample of 1 V [25]. We calculate the magnetic interaction of two Co spheres with a radius of 20 nm. The values in Table 1 show that at short distances all the interactions are on the same order of magnitude, although van der Waals

• interaction dominates at distances below 1 nm. At the typical tip–sample distance during the MFM imaging, around 30 nm, the FvdW can be negligible but the Fe and Fm remain comparable. To avoid a contribution of the short and medium range interactions to the total tip–sample force in MFM, the images are