Exploiting the hierarchical morphology of single-walled and multi-walled carbon nanotube films for highly hydrophobic coatings

• Francesco De Nicola,
• Paola Castrucci,
• Manuela Scarselli,
• Francesca Nanni,
• Ilaria Cacciotti and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 353–360, doi:10.3762/bjnano.6.34

• evaporative drying of single-walled carbon nanotube film during its preparation [36][37][41]. The out-of-plane assembly is the result of the competition between attractive capillary forces and bending stress due to the elasticity of SWCNT film. Once the liquid is completely evaporated, a pattern of micrometer

Strain distribution due to surface domains: a self-consistent approach with respect to surface elasticity

• Javier Fuhr and
• Pierre Müller

Beilstein J. Nanotechnol. 2015, 6, 321–326, doi:10.3762/bjnano.6.30

• integral equation that contains surface elastic constants, Sij. For surfaces with positive Sij the new approach avoids the introduction of a cut-off length. The classical and the new approaches are compared in case of 1-D periodic ribbons. Keywords: surface strain; surface elasticity; strain field

• generalized to other structures such as 2D circular domains. The so-obtained equations are less tractable but the main result remains the same (see Appendix II). Appendix I: Surface elasticity From a thermodynamic point of view all extensive quantities may present an excess at the interface between two media

• ) Classical model in which each domain is characterized by its own supposedly constant surface stress. (b) When taking into account surface elasticity, the surface stress at mechanical equilibrium is no longer constant except far from the boundary. (a) Continuous (red) curve: normalised strain field ε/Δs1

Mechanical properties of MDCK II cells exposed to gold nanorods

• Anna Pietuch,
• Bastian Rouven Brückner,
• David Schneider,
• Marco Tarantola,
• Christina Rosman,
• Carsten Sönnichsen and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 223–231, doi:10.3762/bjnano.6.21

• the elasticity of the epithelial cell line MDCK II probed by AFM and QCM. The combination of these two techniques allows to monitor the influence of nanoparticles on the elastic properties of MDCK II cells both from the apical and basal side. The data permits to compare mechanics of cells exposed to

• of Hertzian mechanics to describe the elasticity of cells we also used a recently introduced tension model treating the cells as a liquid droplet (red continuous lines in Figure 3) [27][28]. According to the tension model we consider the cell as an isotropic elastic shell that produces a restoring

• force in response to indentation with a conical indenter originating from two sources, linear elasticity due to area dilatation and pre-stress (constant tension). Pre-stress is mainly generated by contractile actomyosin, strong adhesion at the cell-borders and interaction of the plasma membrane with the

Boosting the local anodic oxidation of silicon through carbon nanofiber atomic force microscopy probes

• Gemma Rius,
• Matteo Lorenzoni,
• Soichiro Matsui,
• Masaki Tanemura and
• Francesc Perez-Murano

Beilstein J. Nanotechnol. 2015, 6, 215–222, doi:10.3762/bjnano.6.20

• occurs in spite of the relative weakness of the mechanical clamping of the CNF onto the Si apex. The bending elasticity of the CNF-Si probe upon mechanical contact above a few nanonewtons can be compromised to permanent bending (buckling), particularly for longer CNFs, or rupture [22]. Nevertheless, CNF

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• compared to HA alone, an increase in elasticity of up to 120%, a 129% increase in hardness, and an 86% increase in fracture toughness were possible. The BNNT–HA composite also showed a 75% increase in the wear resistance. It was noted that the addition of BNNTs to HA did not have any adverse effect on

The capillary adhesion technique: a versatile method for determining the liquid adhesion force and sample stiffness

• Daniel Gandyra,
• Stefan Walheim,
• Stanislav Gorb,
• Wilhelm Barthlott and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2015, 6, 11–18, doi:10.3762/bjnano.6.2

• ) determination of the water adhesion force and the elasticity of individual hairs (trichomes) of the floating fern Salvinia molesta. (2) The investigation of human head hairs both with and without functional surface coatings (a topic of high relevance in the field of hair cosmetics) was performed. The method

• ], it is interesting to study the properties of the hairs of Salvinia molesta as a model for future developments. The key factors are the high water adhesion of the trichome tips (the “Salvinia effect”, [1]) and the high elasticity of the trichomes [2][3], which allows the pinning of the air–water

• meniscus with respect to the pulling direction. Using this method, we have investigated the hairs (trichomes) of Salvinia molesta and obtained precise values for the water adhesion force of the trichome tip and for the trichome elasticity. These data can now be used as a guideline for the design of

Aquatic versus terrestrial attachment: Water makes a difference

• Petra Ditsche and
• Adam P. Summers

Beilstein J. Nanotechnol. 2014, 5, 2424–2439, doi:10.3762/bjnano.5.252

• surface texture, from smooth to very rough and smooth to hairy or covered with waxes [18][19]. Also the surface energy and with it the wettability of surfaces as well as the elasticity of the substrates are important properties, which can influence attachment [17]. Another important point needs to be

• Table 4 and Table 5. Very large attachment forces are generated by glue adhesion and suction. However, as the given values have been determined under very different conditions (substrates of different material, surface energy, roughness and elasticity; different measurement methods) the values are hard

• macrozobenthos of the marine intertidal. Third, flow forces acting on an animal depend on the flow velocity, which can show huge variations between different habitats and even inside the same habitat. Fourth, the shape and other properties (such as elasticity) of the animal also strongly influences drag and lift

Nanoparticle interactions with live cells: Quantitative fluorescence microscopy of nanoparticle size effects

• Li Shang,
• Karin Nienhaus,
• Xiue Jiang,
• Linxiao Yang,
• Katharina Landfester,
• Volker Mailänder,
• Thomas Simmet and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2388–2397, doi:10.3762/bjnano.5.248

• . Based on studies of the uptake of carboxydextran-coated superparamagnetic iron oxide NPs of 20 and 60 nm by human macrophages, Lunov et al. [49] developed a mathematical model that predicts the wrapping times of different NPs. In addition, the relation between membrane elasticity, cytoskeletal forces

Nanobioarchitectures based on chlorophyll photopigment, artificial lipid bilayers and carbon nanotubes

• Marcela Elisabeta Barbinta-Patrascu,
• Stefan Marian Iordache,
• Ana Maria Iordache,
• Nicoleta Badea and
• Camelia Ungureanu

Beilstein J. Nanotechnol. 2014, 5, 2316–2325, doi:10.3762/bjnano.5.240

• strength (due to C–C sp2 bonds, which is one of the strongest bonds), flexibility without breakage or damage, high elasticity, good electrical conductivity, and chemical stability. These cylindrical graphene nanotubes are considered one of the most attractive nanomaterials. Applicability of CNTs in the

Anticancer efficacy of a supramolecular complex of a 2-diethylaminoethyl–dextran–MMA graft copolymer and paclitaxel used as an artificial enzyme

• Yasuhiko Onishi,
• Yuki Eshita,
• Rui-Cheng Ji,
• Masayasu Onishi,
• Takashi Kobayashi,
• Masaaki Mizuno,
• Jun Yoshida and
• Naoji Kubota

Beilstein J. Nanotechnol. 2014, 5, 2293–2307, doi:10.3762/bjnano.5.238

• compared to the state in which it is not bound (enthalpy–entropy compensation or isokinetic theory) [28]. The enthalpy–entropy decrease is expected to stabilize the complexes against supramolecular stress, by Brownian movement owing to the law of entropy increase (effect of entropy elasticity) [29]. This

• including a guest are now defined as artificial enzymes in which the low-molecular-weight subunit containing the active site is complexed with a high-molecular-weight carrier. These supramolecular assemblies have the characteristic of conformational flexibility (slide-ring elasticity) owing to entropy

• elasticity [32], such as a self-structural change, so that it may become advantageous functionally according to the structural change of a substrate and an intermediary body. MTT assay (WST8) The WST-8 (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium) method is superior to

Nanometer-resolved mechanical properties around GaN crystal surface steps

• Jörg Buchwald,
• Marina Sarmanova,
• Bernd Rauschenbach and
• Stefan G. Mayr

Beilstein J. Nanotechnol. 2014, 5, 2164–2170, doi:10.3762/bjnano.5.225

• ≥ 0} and {(x,y,0) | y ≤ 0} will be neglected as it is constant along x and y, but its treatment would follow the same procedure concerning surface elasticity and symmetry arguments as depicted in the following approach. We first sub-divide the material of interest into infinitesimal cubes of the

• for quantitative mechanical analysis [26]. From this data, we obtained M = 285 GPa with an uncertainty of 5–10%, typical for CR-AFM measurements. According to previous investigations, the radius of curvature, R, of the Si-tip hardly remains below 25 nm during elasticity measurements of stiff materials

• accurate elasticity values and thereby detecting the reduction in the indentation modulus with nanometer-sized steps. Conclusion Tensile stresses lead to a significant local effective reduction in the elastic constants. In the case for a step of several nanometers in height, this effect can lead to

Mechanical properties of sol–gel derived SiO₂ nanotubes

• Boris Polyakov,
• Mikk Antsov,
• Sergei Vlassov,
• Leonid M Dorogin,
• Mikk Vahtrus,
• Roberts Zabels,
• Sven Lange and
• Rünno Lõhmus

Beilstein J. Nanotechnol. 2014, 5, 1808–1814, doi:10.3762/bjnano.5.191

• performed by atomic force microscopy (AFM) under ambient conditions. Half-suspended and three-point bending tests were processed in the framework of linear elasticity theory. Finite element method simulations were used to extract Young’s modulus values from the nanoindentation data. Finally, the Young’s

• solutions based on elasticity theory were used to process cantilever-beam and three-point-bending tests data, while the data from nanoindentation experiments were fitted by using finite element method (FEM) simulations and compared with the analytical models (thin shell or membrane model and Hertz model

• of the NTs. Bending tests inside the HRSEM revealed a limited elasticity and high resistance to fracture of the half-suspended SiO2 NTs. A typical bending experiment is shown in Figure 2. The tip approaches the NT and pushes it near its end (Figure 2a,b). Only negligible elastic shape restoration was

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1649–1663, doi:10.3762/bjnano.5.176

• order to simultaneously acquire the topography and quantify the elasticity of a Ge(001) surface with high resolution [17]. Li and coworkers used a bimodal method in which the first eigenmode was driven by using the phase modulation scheme and the higher mode was driven in open loop, which allowed them

• to obtain images of the sample topography, energy dissipation and elasticity of polymer surfaces immersed in a liquid environment [16]. We have also reported experiments in which images of Vts and Pts were compared for different control schemes applied to the higher mode, including open loop

Influence of the PDMS substrate stiffness on the adhesion of Acanthamoeba castellanii

• Sören B. Gutekunst,
• Carsten Grabosch,
• Alexander Kovalev,
• Stanislav N. Gorb and
• Christine Selhuber-Unkel

Beilstein J. Nanotechnol. 2014, 5, 1393–1398, doi:10.3762/bjnano.5.152

• and position themselves [6]. Once grown on a substrate with defined elasticity, cells adapt their own elasticity to the elasticity of their environment [7]. But not only differentiated cells are influenced by substrate stiffness. For stem cells it has been demonstrated that their differentiation is

• polydimethylsiloxane (PDMS) substrates with Young’s moduli of 4 kPa, 29 kPa, and 128 kPa. These Young’s moduli were chosen in order to cover an elasticity range, for which a significant effect of substrate stiffness on the adhesion of mammalian cells has already been reported [1]. We systematically investigated the

• cool down to room temperature. Elasticity measurements Mechanical properties of PDMS substrates were determined by microindentation using a micro-force measurements device (Basalt-BT01, Tetra GmbH, Ilmenau, Germany) [24]. The recorded force–distance curves were used to calculate the Young’s modulus of

Physical principles of fluid-mediated insect attachment - Shouldn’t insects slip?

• Jan-Henning Dirks

Beilstein J. Nanotechnol. 2014, 5, 1160–1166, doi:10.3762/bjnano.5.127

• , a softer adhesive pad/substrate (with a lower elasticity) deforms more easily at a given external force, resulting in a larger contact area. This larger contact area again increases the radius of the mediating meniscus of the liquid (the liquid is pressed towards the outside of the pad), which then

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

Insect attachment on crystalline bioinspired wax surfaces formed by alkanes of varying chain lengths

• Elena Gorb,
• Sandro Böhm,
• Nadine Jacky,
• Louis-Philippe Maier,
• Kirstin Dening,
• Sasha Pechook,
• Boaz Pokroy and
• Stanislav Gorb

Beilstein J. Nanotechnol. 2014, 5, 1031–1041, doi:10.3762/bjnano.5.116

• different characteristics of crystalline wax surfaces influence the attachment? We also measured adhesion (pull-off) forces of artificial adhesive systems on these surfaces. Here, tacky and deformable polydimethylsiloxane (PDMS) semi-spheres, having elasticity moduli similar to those of insect adhesive pads

A nanometric cushion for enhancing scratch and wear resistance of hard films

• Katya Gotlib-Vainshtein,
• Olga Girshevitz,
• Chaim N. Sukenik,
• David Barlam and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2014, 5, 1005–1015, doi:10.3762/bjnano.5.114

• overlayer based on the elasticity of an underlying PDMS elastomer. To demonstrate the generality of the strategy, different substrates were coated with titania, with and without a soft underlayer. We have previously reported the deposition of thin and uniform titania films on Si, kapton, and

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

• presented the combined study on the material structure and local mechanical properties in tarsal setae of the beetle Coccinella septempunctata and demonstrated the presence of a material gradient at the level of each single seta [12]. Setal elasticity modulus, probed by atomic force microscope (AFM), ranges

• sclerotised basal part of the seta, a rather pronounced longitudinal gradient of material composition was revealed. AFM-nanoindentation experiments have revealed rather low elasticity modulus at the setal tip (1.2 ± 0.3 MPa), but the high one at the setal base (2.43 ± 1.9 GPa) [12]. This information about the

Scale effects of nanomechanical properties and deformation behavior of Au nanoparticle and thin film using depth sensing nanoindentation

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2014, 5, 822–836, doi:10.3762/bjnano.5.94

• understanding of materials behavior during contact. Mechanical properties of interest comprise hardness, Young’s modulus of elasticity, bulk modulus, elastic–plastic deformation, scratch resistance, residual stresses, time-dependent creep and relaxation properties, fracture toughness, fatigue and yield strength

• mechanical properties such as hardness and Young’s modulus of elasticity can be directly obtained as a function of depth. This can be done with a high degree of accuracy, not easily obtained with an AFM. This advancement in technology has proven useful for understanding the mechanical behavior of micro- and

• the elastic modulus. By using this method the Young’s modulus of elasticity and Poisson’s ratio for diamond were taken as 1140 GPa and 0.07, respectively. Poisson’s ratio for Au was taken as 0.42. The data from these experiments is the average of five measurements on five different nanoparticles for

Analytical development and optimization of a graphene–solution interface capacitance model

• Hediyeh Karimi,
• Rasoul Rahmani,
• Reza Mashayekhi,
• Leyla Ranjbari,
• Amir H. Shirdel,
• Niloofar Haghighian,
• Parisa Movahedi,
• Moein Hadiyan and
• Razali Ismail

Beilstein J. Nanotechnol. 2014, 5, 603–609, doi:10.3762/bjnano.5.71

• can satisfy the major requirements of a channel in electrolyte-gated transistor (EGFET) devices due to its ballistic transport, high conductivity, and strong mechanical and elasticity properties. An analytical modeling of the graphene capacitance as a major characteristic of EGFET is studied in this

The softening of human bladder cancer cells happens at an early stage of the malignancy process

• Jorge R. Ramos,
• Joanna Pabijan,
• Ricardo Garcia and
• Malgorzata Lekka

Beilstein J. Nanotechnol. 2014, 5, 447–457, doi:10.3762/bjnano.5.52

• cell mechanics, in particular elasticity, and cancer [5][6]. The first measurements showed that cancerous human bladder cells were softer than non-malignant bladder cells. Further measurements of cancerous cells have confirmed that a lowering of the elastic modulus of the cells is a general feature of

• kPa at 500 nm. The decrease of the Young’s modulus with δ has been previously reported [18] although this effect is still not fully understood [5][18][19]. Effect of cytochalasin D on the elasticity of the cells In order to verify the influence of the actin filaments and their structure on Ecell, some

• overall cell elasticity [16][33]. The correlation between the reduction of the Young’s modulus and the depolymerization of the actin filaments supports a predominant role of these filaments on the stiffness of the cells. In order to verify how the organization of the actin cytoskeleton influences the

Single-asperity contact mechanics with positive and negative work of adhesion: Influence of finite-range interactions and a continuum description for the squeeze-out of wetting fluids

• Martin H. Müser

Beilstein J. Nanotechnol. 2014, 5, 419–437, doi:10.3762/bjnano.5.50

• contributions to the linear elasticity of (frictionless) single-asperity contacts most central to this work are the following: Hertz [4] solved the contact mechanics of a parabolic tip pressed against a substrate for hard-wall repulsion. He found that the contact area Ac and the separation between the two

• inspection of Figure 19a. At small loads, the sensitivity of the gap profile on the details of the model become even more apparent. This result, which can be seen in Figure 19c, is expected, since the elasticity of the tip is no longer relevant. Instead, the force-displacement curve is predominantly

Exploring the complex mechanical properties of xanthan scaffolds by AFM-based force spectroscopy

• Hao Liang,
• Guanghong Zeng,
• Yinli Li,
• Shuai Zhang,
• Huiling Zhao,
• Lijun Guo,
• Bo Liu and
• Mingdong Dong

Beilstein J. Nanotechnol. 2014, 5, 365–373, doi:10.3762/bjnano.5.42

• away from each other. At P2, the rupture length is similar to that at P3. The distribution is slightly wider, which is possibly the result of the tip picking up the underlying fibril at P2. In addition to rupture force and rupture length, other information, such as the molecular elasticity, can be

Challenges and complexities of multifrequency atomic force microscopy in liquid environments

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 298–307, doi:10.3762/bjnano.5.33

• multiple tip–sample impacts for every cycle of the fundamental eigenmode (c). The simulation parameters are ν1 = 14.5 kHz, k1 = 0.03 N/m, Q1 = 2, Q2 = 6, Afree = 75 nm, Asetpoint = 55% and sample modulus of elasticity of 2 GPa (Hertzian contact). Bimodal AFM simulation illustrating the phase and amplitude