Layered calcium phenylphosphonate: a hybrid material for a new generation of nanofillers

• Kateřina Kopecká,
• Ludvík Beneš,
• Klára Melánová,
• Vítězslav Zima,
• Petr Knotek and
• Kateřina Zetková

Beilstein J. Nanotechnol. 2018, 9, 2906–2915, doi:10.3762/bjnano.9.269

• the exfoliation of CaPhP in an amount sufficient for incorporation into polymers involved using propan-2-ol with a strong shear force generated in a high-shear disperser. The filler was tested both in its unexfoliated and exfoliated forms for the preparation of polymer composites, for which a low

• more appropriate for treatment with hydrophobic compounds and, in comparison to pure ethanol, less expensive. The exfoliation of CaPhP in propan-2-ol was studied using various force actions starting with sonication, in addition to the combination with mild shear force, which is produced by pushing the

• particle dispersion through an injection needle by a peristaltic pump. Additionally, a strong shear force created by a high-shear disperser, where the velocity of dispersion was 5 m/s, was also applied. It was found out that the most suitable method for the exfoliation of calcium phenylphosphonate was the

The effect of flexible joint-like elements on the adhesive performance of nature-inspired bent mushroom-like fibers

• Elliot Geikowsky,
• Serdar Gorumlu and
• Burak Aksak

Beilstein J. Nanotechnol. 2018, 9, 2893–2905, doi:10.3762/bjnano.9.268

• kPa in shear and 110 kPa in pull-off stress in the gripping direction, which are twice and ten times higher than that in the releasing direction, respectively. A model to optimize the elastic modulus of the joint-like elements to enable sliding without peeling of the tips has been proposed. Keywords

• than vertically aligned [10]. This tilt, in addition to enhanced performance [11], equips the gecko with directional adhesion properties as shown by Autumn et al. [12]. When they tested setae using a load–drag–pull (LDP) experiment, they found that setae exhibit very high interfacial shear and tension

• when dragged along the direction of the tilt. Opposite to the tilt direction, low shear and compression was measured. They called this phenomenon frictional adhesion suggesting that the adhesive engagement between the gecko’s foot and the surface is enabled only when it pulls the foot in the direction

Low cost tips for tip-enhanced Raman spectroscopy fabricated by two-step electrochemical etching of 125 µm diameter gold wires

• Antonino Foti,
• Francesco Barreca,
• Enza Fazio,
• Cristiano D’Andrea,
• Paolo Matteini,
• Onofrio Maria Maragò and
• Pietro Giuseppe Gucciardi

Beilstein J. Nanotechnol. 2018, 9, 2718–2729, doi:10.3762/bjnano.9.254

• ] and shear-force microscopy (ShFM) [15] allow for chemical imaging of nanostructured materials, surfaces and (bio)molecular layers with a spatial resolution of 4–10 nm in ambient conditions [15][16], and can even reach atomic-level sensitivity in ultrahigh vacuum (UHV) [17][18][19]. Excellent reviews

Friction reduction through biologically inspired scale-like laser surface textures

• Johannes Schneider,
• Vergil Djamiykov and
• Christian Greiner

Beilstein J. Nanotechnol. 2018, 9, 2561–2572, doi:10.3762/bjnano.9.238

• ratio of the shear strength to the yield pressure of the softer metal [51]. Consequently, the tribological properties of the surface are strongly influenced by the subsurface material and the subsurface microstructure is strongly influenced by the plasticity and the nature of the corresponding

Evidence of friction reduction in laterally graded materials

• Roberto Guarino,
• Gianluca Costagliola,
• Federico Bosia and
• Nicola Maria Pugno

Beilstein J. Nanotechnol. 2018, 9, 2443–2456, doi:10.3762/bjnano.9.229

• time evolution obtained with FEM is also shown. In this case, the behaviour is strongly dependent on the thickness of the block. The time interval Δts needed to reach the static friction peak can be estimated starting from the shear stress τ = Gγ, where G is the shear modulus. If the shear deformation

• shear stress is reached (i.e., the static friction threshold). The first detachment of the sliding surface produces a detachment avalanche propagating towards the region with higher static friction threshold, as shown in Figure 5 (see also Supporting Information File 1). Analogous effects on the

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• friction was recently observed for micro- and macroscale systems based on incommensurate sliding between graphene-covered spheres or “nanoscrolls” and substrates [76][77]. Also a decrease of friction shear stress with increasing number of layers has been observed for graphene over Si/SiO2 in vacuum

• , nitrogen, and air [78]. In addition, the shear strength and the interface adhesion energy for graphene on Si/SiO2 was proven to always exceed those of the graphene/Ni(111) interface [78]. The weakly lattice-mismatched graphite/hBN interface is also predicted to be promising for ultra-low-friction

• , only small particles adhere to the sublinear superlubric scaling law, while larger particles show a linear scaling between friction and area, equivalent to a constant shear stress [100]. This can be explained by an enhanced interaction between the Sb atoms and the substrate, as was found by ab initio

Defect formation in multiwalled carbon nanotubes under low-energy He and Ne ion irradiation

• Santhana Eswara,
• Jean-Nicolas Audinot,
• Brahime El Adib,
• Maël Guennou,
• Tom Wirtz and
• Patrick Philipp

Beilstein J. Nanotechnol. 2018, 9, 1951–1963, doi:10.3762/bjnano.9.186

• irradiation is part of these studies [2]. Irradiation-induced defects affect the elastic modulus and the tensile strength of CNTs [3]. For example, for multiwalled carbon nanotubes (MWCNTs), the presence of a small number of defects can increase the interlayer shear strength by several orders of magnitude [4

Nonlinear effect of carrier drift on the performance of an n-type ZnO nanowire nanogenerator by coupling piezoelectric effect and semiconduction

• Yuxing Liang,
• Shuaiqi Fan,
• Xuedong Chen and
• Yuantai Hu

Beilstein J. Nanotechnol. 2018, 9, 1917–1925, doi:10.3762/bjnano.9.183

• the neutral axis [31]. There are two factors to affect : mechanical shear deformations and accumulation of electric carriers. In general, shear deformations result in in-plane electric fields, which lead to carrier drift, while carrier accumulation results in diffusion. Because Δn/n0 is very small in

• the whole ZNW cross section in the linear regime, the largest variance rate of carrier concentration appears along the neutral axis because of the strongest shear deformation there. With increasing end force, the carrier accumulation increases such that there is a stronger nonlinear drift effect on

• difference is between the two endpoints of the x2-axis. Furthermore, the maximal positive potential amplitude is much lower than the maximal negative potential amplitude. In a bent piezoelectric semiconducting beam, two shear deformations produce two in-plane electric field components, E1 and E2. E1 is

Friction force microscopy of tribochemistry and interfacial ageing for the SiO_x/Si/Au system

• Christiane Petzold,
• Marcus Koch and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2018, 9, 1647–1658, doi:10.3762/bjnano.9.157

• at the sliding interface is expected only at higher temperature [26][27] but may be facilitated by frictional energy and by shear mixing. Eutectic AuSi will segregate at room temperature and can thus not be detected after the experiments. We rather suggest that for re-passivation Si reacts with

Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

• Gitanjali Kolhatkar,
• Alexandre Merlen,
• Jiawei Zhang,
• Chahinez Dab,
• Gregory Q. Wallace,
• François Lagugné-Labarthet and
• Andreas Ruediger

Beilstein J. Nanotechnol. 2018, 9, 1536–1543, doi:10.3762/bjnano.9.144

• then glued onto an Abracon Corporation, AB38T-32.768 kHz tuning fork operated in shear force configuration. Image treatment To perform the FFT analysis of the optical images we used the open source software Gwyddion [38]. Any AFM software offering these processing options could be used to achieve the

Atomistic modeling of tribological properties of Pd and Al nanoparticles on a graphene surface

• Alexei Khomenko,
• Miroslav Zakharov,
• Denis Boyko and
• Bo N. J. Persson

Beilstein J. Nanotechnol. 2018, 9, 1239–1246, doi:10.3762/bjnano.9.115

• . Figure 5 depicts the frictional shear stress τ as a function of the contact area. The average shear stress is τ ≈ 9.9 MPa for the Al particles and 12.2 MPa for Pd particles. The values of shear stress in experiments (Figure 2 in [7]) for Sb particles on MoS2 substrate varies from 1 MPa to 3 MPa with

• contact area changes from 1000 nm2 to 100000 nm2. Also, for Sb particles on highly oriented pyrolytic graphite τ is in the range from 0.1 MPa to 1 MPa with the same changes of contact area. In [7] the shear stress decreases linearly with contact area while we find that τ is nearly independent of it. This

• area of Ni nanoparticles changes from 0.2 nN to 0.45 nN and from 0.1 nN to 0.2 nN for Ag, with contact area A from 20 nm2 to 60 nm2 for Ni and from 30 nm2 to 80 nm2 for Ag. The shear stress depending on the contact area of Ag nanoparticles varies from 40 MPa to 90 MPa and from 50 MPa to 140 MPa for Ni

Imaging of viscoelastic soft matter with small indentation using higher eigenmodes in single-eigenmode amplitude-modulation atomic force microscopy

• Miead Nikfarjam,
• Enrique A. López-Guerra,
• Santiago D. Solares and
• Babak Eslami

Beilstein J. Nanotechnol. 2018, 9, 1116–1122, doi:10.3762/bjnano.9.103

• apex, δ is the tip indentation and G(t) is the shear relaxation modulus, which in our case is described by the Generalized Maxwell (also called Wiechert) model (see Figure 1): where τn = ηn/Gn is the ratio between viscosity (ηn) and modulus (Gn) in the n-th arm in the model in Figure 1. The values for

Fatigue crack growth characteristics of Fe and Ni under cyclic loading using a quasi-continuum method

• Ren-Zheng Qiu,
• Yi-Chen Lin and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2018, 9, 1000–1014, doi:10.3762/bjnano.9.93

• that under cyclic loading, the initially damaged area of the crack will coalesce again after compression or shear to the initial geometry leading to a strengthening of the material. If no coalescence appears, the crack spreads rapidly and the material breaks. Moreover, under the cyclic loading of shear

• at any orientation, the slip dislocation observed in the materials considerably affects the release of stress. Keywords: dislocations; fatigue crack growth; materials treatment effects; mechanics; shear stress; Introduction When materials undergo cyclic loading, the growth of cracks in the material

• cyclic loading of tension or shear. To completely analyze the crack growth and expansion characteristics of single-crystal Fe and Ni, the quasi-continuum (QC) method as proposed by Miller and Tadmor [15], instead of the traditional MD method, was employed as its computational efficiency is considerably

Engineering of oriented carbon nanotubes in composite materials

• Razieh Beigmoradi,
• Abdolreza Samimi and
• Davod Mohebbi-Kalhori

Beilstein J. Nanotechnol. 2018, 9, 415–435, doi:10.3762/bjnano.9.41

• of the gap between the two layers and the simultaneous effects of the shear force and mechanical tensile stretch, a slight drag force pulls the CNT in the vertical direction. However, the obtained free CNTs are certainly not vertical relative to the surface of layers. Although the small length of the

• tubes limits the angle of the gap, it also leads to a very small angle deviation in the direction of the shear force. In principle the tubes were not constrained to be quite vertically oriented, but a microscopic view showed satisfactory alignment. To keep the CNTs aligned, the top layer of the CNT/PSF

Liquid-crystalline nanoarchitectures for tissue engineering

• Baeckkyoung Sung and
• Min-Ho Kim

Beilstein J. Nanotechnol. 2018, 9, 205–215, doi:10.3762/bjnano.9.22

• hydrophobic molecular interactions [25][26][27]. Even simple solutions of purified biopolymers and biocolloids, considered as rod-like particles, may exhibit multiple phases of self-organization depending on the rod concentration, ionic conditions, confinements, and shear forces [28][29]. Figure 1 shows an

• . Structurally ordered films have been fabricated by applying unidirectional shear force on a drop of concentrated M13 virus suspension, which resulted in a nematic-like organization of the viruses. The long-range order 2D nematic topography can guide the directional growth of hippocampal neural progenitor cells

• potential along the bundle gel. Collagen-based helical nanofibrillar scaffolds have shown the ability to support the growth of human endothelial cells [104]. The nanofibrils were generated by applying shear stress on a collagen solution in a (chiral) nematic phase. When the cells were seeded in a 3D

Hyperthermic intracavitary nanoaerosol therapy (HINAT) as an improved approach for pressurised intraperitoneal aerosol chemotherapy (PIPAC): Technical description, experimental validation and first proof of concept

• Daniel Göhler,
• Stephan Große,
• Alexander Bellendorf,
• Thomas Albert Falkenstein,
• Mehdi Ouaissi,
• Jürgen Zieren,
• Michael Stintz and
• Urs Giger-Pabst

Beilstein J. Nanotechnol. 2017, 8, 2729–2740, doi:10.3762/bjnano.8.272

• head, where the carbon dioxide flow leads to shear-stress-induced droplet formation as well as droplet acceleration. The generated polydisperse aerosol leaves the nozzle head within a jet stream, which is directed perpendicular to the enclosure surface. The enclosure surface serves thus as an impaction

Exploring wear at the nanoscale with circular mode atomic force microscopy

• Olivier Noel,
• Aleksandar Vencl and
• Pierre-Emmanuel Mazeran

Beilstein J. Nanotechnol. 2017, 8, 2662–2668, doi:10.3762/bjnano.8.266

• . Consequently, the shear stress applied to the contact appears to be not high enough to wear the material. The wear depths determined from the wear profiles (Figure 3D for example) are in the nanometer range. One can calculate from Figure 5 in the steady-state regime for an applied load of 3 µN that about 100

Ferrocholesteric–ferronematic transitions induced by shear flow and magnetic field

• Dmitriy V. Makarov,
• Alexander A. Novikov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2552–2561, doi:10.3762/bjnano.8.255

• magnetic field and a shear flow. Both influences are able to induce the ferrocholesteric–ferronematic transition independently; however, the differences between the magnetic field orientation and the flow alignment direction lead to a competition between magnetic and hydrodynamic mechanisms of influence on

• the ferrocholesteric structure. We analyze various orientations of a magnetic field relative to the direction of a shear flow. The pitch of the ferrocholesteric helix is obtained as function of the strength and the orientation angle of the magnetic field, the shear velocity gradient and a reactive

• parameter. Phase diagrams of ferrocholesteric–ferronematic transition and the pitch of the ferrocholesteric helix as functions of the material and the governing parameters are calculated. We find out that imposing a shear flow leads to a shift of the magnetic field threshold. The value of the critical

Nanoprofilometry study of focal conic domain structures in a liquid crystalline free surface

• Anna N. Bagdinova,
• Evgeny I. Demikhov,
• Nataliya G. Borisenko and
• Sergei M. Tolokonnikov

Beilstein J. Nanotechnol. 2017, 8, 2544–2551, doi:10.3762/bjnano.8.254

• the elastic moduli of liquid crystals. The shear modulus, G, is given as where C and C1 are scaling constants depending on surfactant, t is the relative temperature, γ is the surface tension coefficient of the free surface with FCDs, and L is the FCD dimension. This relation underlines that the

• smectic-A phase with FCDs has different elastic properties compared to an ideal smectic-A sample. Usually, it is observed that for the shear parallel to the smectic layers, the shear modulus is zero. In the case of a SmA sample with a FCD, the free sliding is hindered by the presence of FCDs. This problem

Alternating current magnetic susceptibility of a ferronematic

• Natália Tomašovičová,
• Jozef Kováč,
• Veronika Gdovinová,
• Nándor Éber,
• Tibor Tóth-Katona,
• Jan Jadżyn and
• Peter Kopčanský

Beilstein J. Nanotechnol. 2017, 8, 2515–2520, doi:10.3762/bjnano.8.251

• attention that nematic liquid crystals (LCs) have attracted in recent decades is due to the anisotropy of their physical properties. This anisotropy allows for a realignment of their director (the axis of cylindrical symmetry) by external electrical or magnetic fields, or by shear [1]. In common nematics

Interface conditions of roughness-induced superoleophilic and superoleophobic surfaces immersed in hexadecane and ethylene glycol

• Yifan Li,
• Yunlu Pan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2017, 8, 2504–2514, doi:10.3762/bjnano.8.250

• negative and decrease from a1 to a5. This means that the flow velocity at the reference surface is discontinuous due to the rough structure. The increasing amplitude parameter enhances the fluid shear and inhibits the flow velocity, which forms an area where the average velocity equals that under non-slip

Numerical investigation of the tribological performance of micro-dimple textured surfaces under hydrodynamic lubrication

• Kangmei Li,
• Dalei Jing,
• Jun Hu,
• Xiaohong Ding and
• Zhenqiang Yao

Beilstein J. Nanotechnol. 2017, 8, 2324–2338, doi:10.3762/bjnano.8.232

• tribological performance of a friction pair under the condition of hydrodynamic lubrication can be characterized by the following tribological characteristics: (1) dimensionless average film carrying force; (2) dimensionless average film shear force; (3) friction coefficient. The film carrying force is

• wall of the calculation domain, that is, the area of the micro-dimple unit. A high dimensionless average film carrying force indicates a good load-carrying capacity of the friction pair. In a similar way, as shown in Equation 9, the film shear force is calculated by integrating the shear stress along

• the y-axis on the upper wall over the total calculation domain: where Fy is shear force and τ′ is the shear stress. The dimensionless form of the average film shear force can be obtained by The friction coefficient is defined as the ratio of the dimensionless average film shear force to the

Molecular dynamics simulations of nanoindentation and scratch in Cu grain boundaries

• Shih-Wei Liang,
• Ren-Zheng Qiu and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2017, 8, 2283–2295, doi:10.3762/bjnano.8.228

• . Since the atoms behind the grain boundary were destroyed by the scratch, the slip and the pile up increased gradually. The accumulation of atoms was more obvious at higher processing distances. The destruction of the grain boundary restricted the resistance of the force transmission. Moreover, shear

Material property analytical relations for the case of an AFM probe tapping a viscoelastic surface containing multiple characteristic times

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

Beilstein J. Nanotechnol. 2017, 8, 2230–2244, doi:10.3762/bjnano.8.223

• properties. Throughout these derivations the shear moduli have been employed, although these quantities can be also expressed in terms of their corresponding tensile moduli (E) by using the well-known relation: E = 2G(1 + ν). Figure 4 shows the computational results of a dissipation spectroscopy curve (gray