Colloidal particle aggregation: mechanism of assembly studied via constructal theory modeling

• Scott C. Bukosky,
• Sukrith Dev,
• Monica S. Allen and
• Jeffery W. Allen

Beilstein J. Nanotechnol. 2021, 12, 413–423, doi:10.3762/bjnano.12.33

• with respect to van der Waals and double layer interactions. Preliminary results show that the particle aggregation behavior depends on the initial lattice configuration and solvent properties. Ultimately, our model provides the first constructal framework for predicting the self-assembly of particles

• layers result in repulsion between two particles, this force is constantly opposed by the attractive van der Waals force. The balance between these interparticle forces gives the total DLVO force and highly depends on system parameters, such as the electrolyte concentration and fluid dielectric constant

• dielectric constant, respectively. Conversely, the attractive van der Waals force is given by [14]: where the characteristic energy scale is set by the Hamaker constant, A. It is noted that Equation 1 and Equation 2 assume spherical particles of equal radius and a sufficiently small separation distance (a

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• difference between SEM and SICM images is that the ruffles might be too fragile and are retracted or collapse upon critical point drying. However, especially attractive van der Waals forces might lead to the attachment of ruffles on the membrane surface and, hence, their deformation under vacuum conditions

Extended iron phthalocyanine islands self-assembled on a Ge(001):H surface

• Rafal Zuzak,
• Marek Szymonski and
• Szymon Godlewski

Beilstein J. Nanotechnol. 2021, 12, 232–241, doi:10.3762/bjnano.12.19

• van der Waals interactions [7], but the lack of a gap results in broadening and shifting of the molecular resonances. In recent years, it has been proposed to add a buffer layer between the metallic substrate and the molecules of interest [8][9]. This approach allows for the decoupling of the

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

Bulk chemical composition contrast from attractive forces in AFM force spectroscopy

• Dorothee Silbernagl,
• Media Ghasem Zadeh Khorasani,
• Natalia Cano Murillo,
• Anna Maria Elert and
• Heinz Sturm

Beilstein J. Nanotechnol. 2021, 12, 58–71, doi:10.3762/bjnano.12.5

• determined. Keywords: AFM force spectroscopy; composites; principle component analysis; structure–property correlation; van der Waals forces; Introduction The mechanical properties of small volumes of materials can be measured using various atomic force microscopy (AFM) methods. The well-established force

• to a decrease in the lateral resolution compared to other AFM methods, such as tapping [28]. ncAFM is a more universal applicable method since it is carried out over the whole regime of attractive forces: It is sensitive to electrostatic forces (long range, >30 nm), van der Waals forces (intermediate

• electrostatic interactions since the zero line, Figure 1(I), is stable up to distances of Z < −5 nm. Hence, as the main source of the measured attractive forces we consider electrodynamic interactions (caused by charge fluctuations in dipoles), commonly summarized under the term van der Waals forces. For the

Nanomechanics of few-layer materials: do individual layers slide upon folding?

• Ronaldo J. C. Batista,
• Rafael F. Dias,
• Ana P. M. Barboza,
• Alan B. de Oliveira,
• Taise M. Manhabosco,
• Thiago R. Gomes-Silva,
• Matheus J. S. Matos,
• Andreij C. Gadelha,
• Cassiano Rabelo,
• Luiz G. L. Cançado,
• Ado Jorio,
• Hélio Chacham and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2020, 11, 1801–1808, doi:10.3762/bjnano.11.162

• methods; atomic force microscopy (AFM); molecular dynamics (MD); Raman spectroscopy; nanostructured materials; Introduction Layered materials such as graphite, talc, and transition metal dichalcogenides (TMDs), held together by strong covalent bonds within layers and relatively weak van der Waals

• layered materials as it determines the interlayer slip, which is the dominant mechanism to relieve stress at van der Waals interfaces, leading to phenomena such as the change from plate-like to membrane-like shapes in graphene, hBN, and MoS2 bubbles [12] or the circumferential faceting of multi-walled

Detecting stable adsorbates of (1S)-camphor on Cu(111) with Bayesian optimization

• Jari Järvi,
• Patrick Rinke and
• Milica Todorović

Beilstein J. Nanotechnol. 2020, 11, 1577–1589, doi:10.3762/bjnano.11.140

• with van der Waals (vdW) corrections employing the vdWsurf parametrization [45] of the Tkatchenko–Scheffler method [46]. Previous work found that PBE + vdWsurf adequately describes organic molecules on metal surfaces [45][47][48]. Our converged settings employ tier-1 basis sets with light grid settings

Design of V-shaped cantilevers for enhanced multifrequency AFM measurements

• Mehrnoosh Damircheli and
• Babak Eslami

Beilstein J. Nanotechnol. 2020, 11, 1525–1541, doi:10.3762/bjnano.11.135

• geometries while interacting with polystyrene (PS) and gold (Au) surfaces in bimodal AFM. The tip–sample force interactions are categorized into long-range van der Waals forces and short-range forces described by the Derjaguin, Muller and Toporov (DMT) model. The instantaneous tip distance d is defined as d

• forces (i.e., van der Waals forces) and short-range repulsive forces (i.e., DMT model) while experimental work was done purely in the repulsive regime, in which material properties are more dominant on the dynamics of the cantilever. It should also be mentioned that the since all simulation studies were

Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• of the macrocycle now amounts to only 0.5 Å while the bond length of the Co atom of 1 to the surface oxygen is now 3.0 Å. This means the distance between the molecule and the surface corresponds closely to the sum of the van der Waals radii of carbon and oxygen (3.2 Å). The binding energy is reduced

Controlling the electronic and physical coupling on dielectric thin films

• Philipp Hurdax,
• Michael Hollerer,
• Larissa Egger,
• Georg Koller,
• Xiaosheng Yang,
• Anja Haags,
• Serguei Soubatch,
• Frank Stefan Tautz,
• Mathias Richter,
• Alexander Gottwald,
• Peter Puschnig,
• Martin Sterrer and
• Michael G. Ramsey

Beilstein J. Nanotechnol. 2020, 11, 1492–1503, doi:10.3762/bjnano.11.132

• charge transfer, as evidenced by the absence of an emission from the LUMO in photoemission tomography [21]. This implies that the van der Waals interaction with the metal is sufficient to planarize the molecule. From the STM images shown here of 6P on the MgO(100)/Ag(100) films it is not possible to

• for 6P films on MgO(100)/Ag(100) with a high proportion of charged molecules showed faint superstructure spots, which suggest a later molecular spacing of 6.6 Å. The van der Waals dimensions of 6P (6.7 × 27.2 Å) [26] are close to the unit cell (6.35 × 27.47 Å) which is commensurate with MgO(100). The

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

• Domenik M. Zimmermann,
• Knud Seufert,
• Luka Ðorđević,
• Tobias Hoh,
• Sushobhan Joshi,
• Tomas Marangoni,
• Davide Bonifazi and
• Willi Auwärter

Beilstein J. Nanotechnol. 2020, 11, 1470–1483, doi:10.3762/bjnano.11.130

• , constituted the extended islands. As no pyridinic N atom was directly involved in the interrow interaction, the stabilization of the islands was attributed to van der Waals forces. The straight edges reflected the row structure of the islands (see Figure 4a). The unit cell of the assembly (grey rectangle in

Antimicrobial metal-based nanoparticles: a review on their synthesis, types and antimicrobial action

• Matías Guerrero Correa,
• Fernanda B. Martínez,
• Cristian Patiño Vidal,
• Camilo Streitt,
• Juan Escrig and
• Carol Lopez de Dicastillo

Beilstein J. Nanotechnol. 2020, 11, 1450–1469, doi:10.3762/bjnano.11.129

• ]. Silver, gold, zinc oxide, and titanium dioxide NPs can be attracted to the cell wall by electrostatic attraction [161], van der Waals forces [162], and hydrophobic interactions [163], inducing changes in the shape, function and permeability of the cells. Proteins and DNA Proteins play a fundamental role

Protruding hydrogen atoms as markers for the molecular orientation of a metallocene

• Linda Laflör,
• Michael Reichling and
• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1432–1438, doi:10.3762/bjnano.11.127

• finding which we attribute to the different van der Waals radii of CO and xenon. From a comparison with the molecular geometry we can confidentially assign the dark weights of the dumbbell to repulsive interactions with the top hydrogen atoms Htop (see Figure 1a). The bright halo around these two weights

One-step synthesis of carbon-supported electrocatalysts

• Sebastian Tigges,
• Nicolas Wöhrl,
• Ivan Radev,
• Ulrich Hagemann,
• Markus Heidelmann,
• Thai Binh Nguyen,
• Stanislav Gorelkov,
• Stephan Schulz and
• Axel Lorke

Beilstein J. Nanotechnol. 2020, 11, 1419–1431, doi:10.3762/bjnano.11.126

• ] or the supercritical CO2 method [14]) to form the required electrocatalyst [6]. The third step is technically challenging and has a substantial influence on the homogeneous distribution of NPs on the support. Since the NPs are typically bound to the support by weak van der Waals forces, the

On the frequency dependence of viscoelastic material characterization with intermittent-contact dynamic atomic force microscopy: avoiding mischaracterization across large frequency ranges

• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 1409–1418, doi:10.3762/bjnano.11.125

• eigenfrequency [5], but only the fundamental eigenfrequency is driven. The cantilever parameters used are provided in Table 2. The tip–sample forces consist of two components. The attractive van der Waals interactions were modeled through the Hamaker equation, as is also customary in AFM [2]. The repulsive

Analysis of catalyst surface wetting: the early stage of epitaxial germanium nanowire growth

• Owen C. Ernst,
• Felix Lange,
• David Uebel,
• Thomas Teubner and
• Torsten Boeck

Beilstein J. Nanotechnol. 2020, 11, 1371–1380, doi:10.3762/bjnano.11.121

• interfacial potentials. For this purpose, the interfacial potentials were calculated by using three different methods: an empirical approach, in which the wetting angle was taken into account (“WA model”); a completely theoretical approach, in which the interface was described purely by van der Waals

• the vW model fails since gold droplets are formed on the silicon oxide surface. A deep insight into the characteristics and properties of the observed material is needed to perform calculations using van der Waals interactions. However, thermal silicon oxide has no defined crystallographic orientation

• . Even for thermal silicon oxide surfaces, which are grown in a well-controlled manner, only approximate values are given in the literature [23]. In addition, the van der Waals energy between silicon oxide and gold is repulsive, which is unsuitable for a model that assumes two surfaces that are brought

Influence of the magnetic nanoparticle coating on the magnetic relaxation time

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2020, 11, 1207–1216, doi:10.3762/bjnano.11.105

• conservative torques acting on the i-th nanoparticle. The forces acting on the nanoparticles of the system are the van der Waals forces, electrostatic repulsive forces, magnetic dipolar forces, steric repulsion forces and the random Brownian force [19][26][27][28][29]. The stabilisation of magnetic particles

• ., surface-to-surface separation between nanoparticles), and on the surface density of the polymer coating layer. Thus, the model uses the van der Waals interaction force equation, as follows [21]: where ri and rj are spherical particle radii of the i-th and j-th nanoparticles, is the versor of the

Vibration analysis and pull-in instability behavior in a multiwalled piezoelectric nanosensor with fluid flow conveyance

• Sayyid H. Hashemi Kachapi

Beilstein J. Nanotechnol. 2020, 11, 1072–1081, doi:10.3762/bjnano.11.92

• analysis; surface/interface effect; van der Waals force; viscous fluid velocity; Introduction Nanomechanical sensors and resonators, especially when combined with piezoelectric materials, are widely used in modern engineering, which encompasses numerous, diverse fields of science and technology

• (TWNTs) subjected to the interlayer van der Waals (vdW) force in the framework of the Sanders–Koiter shell theory [12]. Also, based on nonlocal cylindrical shell theory, Ghorbanpour Arani et al. studied nonlinear vibration and instability of double-walled boron nitride nanotubes [13]. Malihi et al

• . investigated the effect of nonzero initial conditions, the nonlinear coefficient of squeeze film air damping, and the van der Waals effect on the stability of torsional nanomirrors for the obtained dynamic pull-in instability voltage using the size effect [14]. Fakhrabadi et al. utilized the modified couple

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• minimize the interaction energy (van der Waals and electrostatic) even at the expense of molecule deformation. Another issue that needs to be addressed is the rotation of the manipulated molecules. The majority of Sn-down molecules adsorb over titanium rows with their diagonal parallel to the [001

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

• K. Priya Madhuri,
• Abhay A. Sagade,
• Pralay K. Santra and
• Neena S. John

Beilstein J. Nanotechnol. 2020, 11, 814–820, doi:10.3762/bjnano.11.66

• the highly delocalized macrocycles. The competing interfacial van der Waals forces and molecule–molecule interactions lead to the formation of a small fraction of triclinic moieties. The nanoscale electrical characterization of the thin PbPc layer on graphene by means of conducting atomic force

• consider any influence of the underlying substrate on the MPc orientation. It has been shown that a monolayer of graphene, due to its extremely thin nature, exhibits transparency to the wetting behavior on substrates where van der Waals forces are the dominant surface–water interactions [14]. The wetting

• polymer residues via thermal treatment [30]. Recently, Rafiee et al. found, in the context of wetting, that the van der Waals forces are not disrupted by the graphene sheet as it is extremely thin (ca. 0.3 nm) [14]. Hence, we consider that the edge-on configurations are formed under the influence of the

Light–matter interactions in two-dimensional layered WSe₂ for gauging evolution of phonon dynamics

• Avra S. Bandyopadhyay,
• Chandan Biswas and
• Anupama B. Kaul

Beilstein J. Nanotechnol. 2020, 11, 782–797, doi:10.3762/bjnano.11.63

• variation with geometrical confinement in some TMDCs has been studied recently [7]. Monolayer (1L) TMDCs consist of a plane of a transition metal, M, sandwiched by chalcogenides, X, on either side to yield the stoichiometry MX2 [8]. The interlayer bonding in most ML TMDCs is through the weak van der Waals

• [32] (Figure 1b), and a van der Waals gap g = 3.36 Å [33] (Figure 1c, left). The crystal structure of WSe2 (0001) consists of a repetition of Se–W–Se trilayers, as depicted in Figure 1b. The irreducible representation of the phonon modes at the center of the Brillouin zone in WSe2 can be described by

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• at an even more emerging stage of development that can serve as alternative material platforms. These are generally the wide-bandgap group II–VI and III–V materials, such GaN [32][33][34] and ZnO [35][36][37], and low-dimensional van der Waals materials, including the transition metal dichalcogenide

Quantitative determination of the interaction potential between two surfaces using frequency-modulated atomic force microscopy

• Nicholas Chan,
• Carrie Lin,
• Tevis Jacobs,
• Robert W. Carpick and
• Philip Egberts

Beilstein J. Nanotechnol. 2020, 11, 729–739, doi:10.3762/bjnano.11.60

• z−6 dependency that can be mathematically derived to describe long-range van der Waals force interactions [55]. However, the repulsive term in the 6-12 LJ pair potential has a z−12 dependency that is empirical and computationally simple [32][56]. While it is known that the repulsive term in the 6-12

Exfoliation in a low boiling point solvent and electrochemical applications of MoO₃

• Matangi Sricharan,
• Bikesh Gupta,
• Sreejesh Moolayadukkam and
• H. S. S. Ramakrishna Matte

Beilstein J. Nanotechnol. 2020, 11, 662–670, doi:10.3762/bjnano.11.52

• distorted edge- and corner-sharing MoO6 octahedra. The layers are linked through weak out-of-plane van der Waals interactions. For exfoliation of MoO3, 2-butanone, a low boiling point solvent, was chosen the HSP values of which match well with those of MoO3 (Supporting Information File 1, Table S1). To

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon

• Hyung Jun An,
• Jong Min Park,
• Nazmul Abedin Khan and
• Sung Hwa Jhung

Beilstein J. Nanotechnol. 2020, 11, 597–605, doi:10.3762/bjnano.11.47

• ) 8.1 times that of commercial, activated carbon for AR1. The remarkable adsorption of AR1 and JGB over KOH-900 could be explained by the combined mechanisms of hydrophobic, π–π, electrostatic and van der Waals interactions. Keywords: acid red 1; adsorption; bulky dye molecules; Janus green B

• effective adsorption of small MO or MB since van der Waals interactions rely on adequate matching between pore and adsorbates. On the contrary, bulky dye molecules such as AR1 and JGB can interact effectively with KOH-900 via van der Waals interactions, which relies on the suitable pore size of KOH-900 for

• the bulky dye molecules. In summary, the remarkable adsorption of AR1 and JGB over KOH-900 can be explained by the combined mechanisms of hydrophobic, π–π, electrostatic and van der Waals interactions. Competitiveness of KOH-900 in adsorption of dyes Based on the remarkable performance of KOH-900 in