Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices

• Giulia Lo Dico,
• Bernd Wicklein,
• Lorenzo Lisuzzo,
• Giuseppe Lazzara,
• Pilar Aranda and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2019, 10, 1303–1315, doi:10.3762/bjnano.10.129

• , MWCNTs and poly(vinyl alcohol) [25], sepiolite, graphene nanoplatelets, and biopolymers (e.g., alginate, gelatine) [26] and cellulose or foams of microfibrillated cellulose and starch [47], which exhibit Young’s moduli in the range from 0.1 to 9 GPa. The high stiffness of these materials has been

On the relaxation time of interacting superparamagnetic nanoparticles and implications for magnetic fluid hyperthermia

• Andrei Kuncser,
• Nicusor Iacob and
• Victor E. Kuncser

Beilstein J. Nanotechnol. 2019, 10, 1280–1289, doi:10.3762/bjnano.10.127

• of thirteen magnetic nanoparticles (each of size 4.4 × 4 × 4 nm in order to assure the uniaxial magnetic anisotropy) with no magneto-crystalline anisotropy, a stiffness constant (A) of 1.3 × 10−11 J/m3 and a spontaneous magnetization (Ms) of 8.5 × 105 A/m have been arranged in a bidimensional

Comparing a porphyrin- and a coumarin-based dye adsorbed on NiO(001)

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2019, 10, 874–881, doi:10.3762/bjnano.10.88

• at 80 °C. Scanning probe microscopy All measurements were carried out in dark using a custom-built atomic force microscope operating under UHV at RT. All AFM images were recorded in the non-contact mode, using silicon cantilevers (Nanosensors PPP-NCL, stiffness k = 20–30 N/m, resonance frequency f1

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

• Aaron Mascaro,
• Yoichi Miyahara,
• Tyler Enright,
• Omur E. Dagdeviren and
• Peter Grütter

Beilstein J. Nanotechnol. 2019, 10, 617–633, doi:10.3762/bjnano.10.62

• (interferometry, for example [53]) and cleaner excitation schemes such as photothermal excitation [54]. Using probes of higher stiffness, however, is not expected to be advantageous due to the inverse relationship between the measured phase shift and cantilever spring constant. Validation measurement To

Mechanical and thermodynamic properties of Aβ₄₂, Aβ₄₀, and α-synuclein fibrils: a coarse-grained method to complement experimental studies

• Adolfo B. Poma,
• Horacio V. Guzman,
• Mai Suan Li and
• Panagiotis E. Theodorakis

Beilstein J. Nanotechnol. 2019, 10, 500–513, doi:10.3762/bjnano.10.51

• range of applications of AFM technique span from biomolecules to single cells [31][56][57]. The AFM nanoindentation force–distance curves typically depend on the correct determination of the cantilever stiffness and only measurements of biological fibrils located at the centre of the fibril are

Nitrous oxide as an effective AFM tip functionalization: a comparative study

• Taras Chutora,
• Bruno de la Torre,
• Pingo Mutombo,
• Jack Hellerstedt,
• Jaromír Kopeček,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2019, 10, 315–321, doi:10.3762/bjnano.10.30

• and the simulated AFM images. The lateral stiffness was set to k = 0.25 N/m. The correlation of the experimental evidence and theory permit us to understand the nature and origin of the chemical contrast. Adsorption of N2O molecules on the Au(111) substrate. (a) Overview STM image (100 mV, 10 pA, 50

Pull-off and friction forces of micropatterned elastomers on soft substrates: the effects of pattern length scale and stiffness

• Peter van Assenbergh,
• Marike Fokker,
• Julian Langowski,
• Jan van Esch,
• Marleen Kamperman and
• Dimitra Dodou

Beilstein J. Nanotechnol. 2019, 10, 79–94, doi:10.3762/bjnano.10.8

• adhesiveness of biological micropatterned adhesives primarily relies on their geometry (e.g., feature size, architecture) and material properties (e.g., stiffness). Over the last few decades, researchers have been mimicking the geometry and material properties of biological micropatterned adhesives. The

• performance of these biomimetic micropatterned adhesives is usually tested on hard substrates. Much less is known about the effect of geometry, feature size, and material properties on the performance of micropatterned adhesives when the substrate is deformable. Here, micropatterned adhesives of two stiffness

• degrees (Young’s moduli of 280 and 580 kPa) were fabricated from poly(dimethylsiloxane) (PDMS) and tested on soft poly(vinyl alcohol) (PVA) substrates of two stiffness degrees (12 and 18 kPa), and on hard glass substrates as a reference. An out-of-the-cleanroom colloidal lithographic approach was

A comparison of tarsal morphology and traction force in the two burying beetles Nicrophorus nepalensis and Nicrophorus vespilloides (Coleoptera, Silphidae)

• Liesa Schnee,
• Benjamin Sampalla,
• Josef K. Müller and
• Oliver Betz

Beilstein J. Nanotechnol. 2019, 10, 47–61, doi:10.3762/bjnano.10.5

• morphology of the hair types (cf. Figure 2) in the two species, possible differences in the shape and the stiffness of the adhesive tips have not been investigated in this study and may play an important role [10][42]. Previous studies have suggested a decreased fluidity in the tarsal adhesion-mediating

• (CSM Instruments, Peseux, Switzerland) equipped with a dual-beam cantilever STH-001 as previously described [19]. This cantilever features a highly sensitive dual-beam spring able to measure forces in the x-direction (Ft, stiffness = 4.8139 mN/µm) and z-direction (Fn, stiffness = 0.5122 mN/µm) with a

Bidirectional biomimetic flow sensing with antiparallel and curved artificial hair sensors

• Claudio Abels,
• Antonio Qualtieri,
• Toni Lober,
• Alessandro Mariotti,
• Lily D. Chambers,
• Massimo De Vittorio,
• William M. Megill and
• Francesco Rizzi

Beilstein J. Nanotechnol. 2019, 10, 32–46, doi:10.3762/bjnano.10.4

• 2 μm encapsulation layer to all sides of the cantilever beams as well as the flow sensor substrate (including circuitry). This process tunes the mechanical properties (flexural stiffness) of the artificial hair sensor, as described in [46]. Experimental methodology Three different experiments were

Contact splitting in dry adhesion and friction: reducing the influence of roughness

• Jae-Kang Kim and
• Michael Varenberg

Beilstein J. Nanotechnol. 2019, 10, 1–8, doi:10.3762/bjnano.10.1

• point as the point at which the adhesive flap bending needed for adaptation to surface irregularities becomes too energy consuming. To this end, the bending stiffness of the adhesive flaps is the decisive property and, hence, the flap thickness is the most important characteristic size (it is raised to

Investigation of CVD graphene as-grown on Cu foil using simultaneous scanning tunneling/atomic force microscopy

• Majid Fazeli Jadidi,
• Umut Kamber,
• Oğuzhan Gürlü and
• H. Özgür Özer

Beilstein J. Nanotechnol. 2018, 9, 2953–2959, doi:10.3762/bjnano.9.274

• nanostructures. With the use of sub-angstrom oscillation amplitudes, far from resonance, the tip–sample force corrugation in the images obtained at very close separations, can be calculated using F = klever·(A0 – A), where klever is the lever stiffness, A0 the free oscillation amplitude, i.e., far from the

• taken on several samples showed the presence of dominantly single-layer graphene [36]. Results and Discussion We used a custom-made tungsten tip–cantilever probe [32] the stiffness of which was estimated from thermal oscillations to be about 53 N/m. The simultaneously acquired STM topography and force

• (forward scan); (c) force in constant-height mode (backward scan). Scale bar values are in units of Å in STM and nN in force images. Obtained with a W tip and cantilever of stiffness k = 53 N/m and a resonance frequency f0 = 31.5 kHz; drive frequency f = 15 kHz. The image size is 11 × 11 Å2, Vsample = −0.5

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

• to improve their stiffness, melt behavior, mechanical characteristic, durability and other properties of polymer products is a well-known process and has been studied for decades. Platelets of clay minerals are suitable and widespread fillers. In addition, some clays can be exfoliated thanks to their

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

• testing different scenarios, LDP results have shown the significant influence of the stiffness gradient in the robustness of the adhesion and the adaptability of the contact. Parness et al. [23] fabricated one of the first synthetic structures which performed similar to a gecko. While their adhesion was

• compliance and facilitates the use of such a stiff polymer. The joint stiffness was controlled using three polyurethane materials of elastic moduli Ej = 0.45, 8.89 and 126 MPa as the joint material. The final array of the composite fibers consisted of a stiff stalk and tip linked by a soft joint as shown in

• . Let us model the flexible joint as a torsional spring of stiffness added to the end of the fiber, where Ej is the elastic modulus of the joint material and f is the thickness of the joint in terms of overall effective length L of the fiber, and I is the area moment of inertia of the fiber assuming

Effective sensor properties and sensitivity considerations of a dynamic co-resonantly coupled cantilever sensor

• Julia Körner

Beilstein J. Nanotechnol. 2018, 9, 2546–2560, doi:10.3762/bjnano.9.237

• maintaining the ease of detection. Experimentally, a low-stiffness nanocantilever is coupled to an easy to read out microcantilever and the eigenfrequencies of both beams are brought close to one another. This results in a strong interplay between both beams and, hence, any interaction applied at the

• cantilever mass. Another approach of reaching femtonewton force sensitivity has been demonstrated for optomechanical cantilever sensors by optimizing cantilever design for high quality factors (in the order of 106). Consequently, cantilevers with rather high stiffness (kN/m) can be used, avoiding the snap-to

• stiffness of the nanocantilever and room temperature were assumed. A decrease in stiffness, especially of the nanocantilever, and low temperatures will lead to much more gain in sensitivity. With the derived expressions within this work, a fast and easy way to estimate the potential sensitivity is given

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

• graded materials; numerical simulations; Introduction Materials with a gradient in their physical or elastic properties are widely found in nature. Several known biological systems have developed specialized functionalities due to stiffness, density or composition gradients. Beetles, for instance

• , display setae with a graded stiffness that optimises the adhesive performance on rough surfaces [1]. Hardness and stiffness gradients are of fundamental importance in the biomechanics of contacts, since they allow increased resistance against wear, impact, penetration and crack propagation [2][3][4][5][6

• stiffness of the springs along the axis is set to Kint = 3/4 Elz, and of the diagonal springs to Kint/2 [37]. Thus, the internal elastic force exerted on the generic block i by its neighbour j is Fint(ij) = kij (rij − lji) (rj − ri) /rij, where ri and rj are the position vectors of blocks i and j

Magnetism and magnetoresistance of single Ni–Cu alloy nanowires

• Andreea Costas,
• Camelia Florica,
• Elena Matei,
• Maria Eugenia Toimil-Molares,
• Ionel Stavarache,
• Andrei Kuncser,
• Victor Kuncser and
• Ionut Enculescu

Beilstein J. Nanotechnol. 2018, 9, 2345–2355, doi:10.3762/bjnano.9.219

• also related to an exchange length parameter, λex = π√(A/K), where A is the exchange stiffness and K is the anisotropy constant, respectively. Even for single-component metallic nanowires (e.g., Ni) of high aspect ratio, different magnetization reversal mechanisms might be in work (from the simplest

• gradient method were performed for all points obtained on the hysteresis plot. In addition to the abovementioned geometrical aspects, the simulations require also two additional magnetic parameters: (i) the spontaneous magnetization (well approximated by the saturation magnetization) and (ii) the stiffness

• [27]. However, the above estimations allowed us to perform micromagnetic simulations on similar cylindrical magnetic structures of high aspect ratio with saturation magnetizations of about 105 A·m−1 and stiffness constants of about 10−22 J·m−1 (as specific to Ni and Ni alloys) [31][32]. The

Fabrication of photothermally active poly(vinyl alcohol) films with gold nanostars for antibacterial applications

• Mykola Borzenkov,
• Maria Moros,
• Claudia Tortiglione,
• Serena Bertoldi,
• Nicola Contessi,
• Silvia Faré,
• Angelo Taglietti,
• Agnese D’Agostino,
• Piersandro Pallavicini,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2018, 9, 2040–2048, doi:10.3762/bjnano.9.193

• stress–strain curves of the three types of films followed the same trend, however being characterized by different elastic modulus, maximum stress and maximum strain values. In particular, PVA films without GNSs showed the lowest stiffness value in comparison with both types of PVA-GNS films (p < 0.05

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

Preparation of micro/nanopatterned gelatins crosslinked with genipin for biocompatible dental implants

• Reika Makita,
• Tsukasa Akasaka,
• Seiichi Tamagawa,
• Yasuhiro Yoshida,
• Saori Miyata,
• Hirofumi Miyaji and
• Tsutomu Sugaya

Beilstein J. Nanotechnol. 2018, 9, 1735–1754, doi:10.3762/bjnano.9.165

• of vinculin spots on pillars with heights of 2 µm after 7 days of culturing appeared weaker than the strength after 1 day of culturing. The difference in distribution or strength of vinculin spots may be caused by substrate stiffness [63]. These data support the concept that patterning of gelatin

Electrostatically actuated encased cantilevers

• Benoit X. E. Desbiolles,
• Gabriela Furlan,
• Adam M. Schwartzberg,
• Paul D. Ashby and
• Dominik Ziegler

Beilstein J. Nanotechnol. 2018, 9, 1381–1389, doi:10.3762/bjnano.9.130

• immersed in a viscous fluid. Quantitative measurements of stiffness, energy dissipation and tip–sample interactions using dynamic force sensors remain challenging due to spurious resonances of the system. Results: We demonstrate for the first time electrostatic actuation with a built-in electrode. Solely

• ≈ 90 μm) with a stiffness of k = 4 N·m−1 and a resonance frequency of f0 = 144.525 kHz and Qair = 36.5 is used. After immersion in water the quality factor remained high Qwater = 27.4, which enables high-resolution imaging with small interaction forces in liquids. Moreover, the clean electrostatic

• , the well-known expression for deflection of a uniformly loaded cantilever can be used. y(l) = ql4/(8EI). Inserting the static stiffness kstat = 3EI/l3 and q = Fdc/l we can express y(l) as a function of the capacitance gradient (C′), stiffness (kstat) and electrical potentials (Udc, UCPD, and Uac): To

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

• different temperatures, and showed how the static friction and contact stiffness depend on the contact area. They observed “contact aging” due to stress-aided, thermally activated atomic rearrangement processes. The term “contact aging” [6] is related to time-dependent atomic reconstructions at the

Electrostatic force spectroscopy revealing the degree of reduction of individual graphene oxide sheets

• Yue Shen,
• Ying Wang,
• Yuan Zhou,
• Chunxi Hai,
• Jun Hu and
• Yi Zhang

Beilstein J. Nanotechnol. 2018, 9, 1146–1155, doi:10.3762/bjnano.9.106

• force gradients cause shifts of Δf0 in the resonance frequency with a proportional relationship [30]: where k is the stiffness (or spring constant) of the cantilever. Resonance shifts also give rise to phase shifts, ∆φ, used to generate an image of the electric force gradients. In EFM imaging, the

Field-controlled ultrafast magnetization dynamics in two-dimensional nanoscale ferromagnetic antidot arrays

• Anulekha De,
• Sucheta Mondal,
• Sourav Sahoo,
• Saswati Barman,
• Yoshichika Otani,
• Rajib Kumar Mitra and
• Anjan Barman

Beilstein J. Nanotechnol. 2018, 9, 1123–1134, doi:10.3762/bjnano.9.104

• Oe−1, anisotropy field Hk = 0, saturation magnetization Ms = 860 emu cm−3, and exchange stiffness constant A = 1.3 × 10−6 erg cm−1. The material parameters were extracted by measuring the variation of precessional frequency (f) with bias magnetic field H for a Py thin film and by fitting them using

• Kittel formula, The exchange stiffness constant A is obtained from literature [39]. A pulsed field of peak value of 30 Oe, 10 ps rise/fall time and 20 ps pulse duration is used perpendicular to the sample plane, while a damping coefficient α = 0.008 is used during dynamic simulations. The experimentally

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

• the first three flexural eigenmodes, using an individual equation of motion for each of them, all coupled through the tip–sample forces: Here zi, ki, Qi and refer to the i-th (with i = 1, 2, 3) eigenmode displacement, cantilever stiffness, cantilever quality factor, and resonance frequency

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• stiffness, and as transparent layers used for heated, mist and ice-free, window panes [35]. By the end of 2003, Mercedes-Benz brought a NP-based clear coat into series production for both metallic and nonmetallic paint finishes. The coating increases the scratch resistance and enhances the gloss. Liquid

• nanocomposite. Nacre is designed by alternating micrometer-sized and sub-micrometer CaCO3 aragonite platelets, which are separated by a thin layer of bio-macromolecular “glue”. Enhanced stiffness, impact resistance, strength, and toughness are some of the mechanical properties that enable using nacre’s unique