Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

• Alexandra M. Greiner,
• Adria Sales,
• Hao Chen,
• Sarah A. Biela,
• Dieter Kaufmann and
• Ralf Kemkemer

Beilstein J. Nanotechnol. 2016, 7, 1620–1641, doi:10.3762/bjnano.7.155

• solution with the desired polymer is ejected through a capillary towards a substrate by applying a high-voltage electric field. Long fibers with diameters in the range from 2 nm to several micrometers can be generated [69][70][71][72]. However, electrospinning has not been yet satisfactorily employed to

Surface roughness rather than surface chemistry essentially affects insect adhesion

• Matt W. England,
• Tomoya Sato,
• Makoto Yagihashi,
• Atsushi Hozumi,
• Stanislav N. Gorb and
• Elena V. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1471–1479, doi:10.3762/bjnano.7.139

• to that observed in air. The oil-covered hairy pads on the feet of the beetle show a pinning effect, which retains air bubbles, and capillary attachment is produced by bubbles in contact with the hydrophobic substrate. Additionally, the liquid bridges of the pad between the foot and the substrate

• also produce capillary forces. Inspired by this idea, artificial silicone polymer structures with underwater adhesive properties were fabricated [34]. Thus, the relationship between surface structures and the attachment of insects, in combination with their particular chemical/physical properties, has

False positives and false negatives measure less than 0.001% in labeling ssDNA with osmium tetroxide 2,2’-bipyridine

• Anastassia Kanavarioti

Beilstein J. Nanotechnol. 2016, 7, 1434–1446, doi:10.3762/bjnano.7.135

• properties of the degradation products via nanopore translocation can be evaluated to assure base calling quality in a DNA sequencing effort. Keywords: α-hemolysin; capillary electrophoresis; DNA sequencing; high-performance liquid chromatography; nanopores; osmium tetroxide bipyridine; osmylated oligos

• (HPLC) or capillary electrophoresis (CE). It turns out that both analytical tools clearly resolve DNA from the OsBp label, which appears as a single peak with the methods used in this report. For the more typical cases where the oligo/DNA has 5 or more pyrimidines, the resolution between intact and

• lower fraction of T and C in the oligo. The ratio T/Ntot = 0.30 for the 20-mer and 0.33 for M13mp18; (T + C)/Ntot equals 0.50 for the 20-mer and 0.54 for M13mp18 [31]. Upper limits for purine osmylation and DNA backbone degradation (false positives) Capillary zone electrophoresis (CZE) methods were

Three-gradient regular solution model for simple liquids wetting complex surface topologies

• Sabine Akerboom,
• Marleen Kamperman and
• Frans A. M. Leermakers

Beilstein J. Nanotechnol. 2016, 7, 1377–1396, doi:10.3762/bjnano.7.129

• cavities. In such structures we should anticipate the occurrence of capillary condensation or, alternatively, capillary drying. For this reason we use the regular solution model to study classical capillary condensation. To this end we consider a system that contains two surfaces. One at z = 0 and another

• oversaturation of water in the vapour phase; a phenomenon named after Kelvin. With oversaturation of the system, which necessarily occurs in our calculations due to the finite size of our droplets, one will invariably get closer to the spinodal point of the capillary condensation process. Hence, oversaturation

• may trigger the filling of confined regions by the liquid. Small droplets cause a stronger oversaturation than larger droplets and the presence of small droplets may result in a spontaneous filling of the voids by capillary condensation when this may not yet occur for larger drops. The radius

Viability and proliferation of endothelial cells upon exposure to GaN nanoparticles

• Tudor Braniste,
• Ion Tiginyanu,
• Tibor Horvath,
• Simion Raevschi,
• Serghei Cebotari,
• Marco Lux,
• Axel Haverich and
• Andres Hilfiker

Beilstein J. Nanotechnol. 2016, 7, 1330–1337, doi:10.3762/bjnano.7.124

• capillary tubes and thus develop new blood vessels via ramification of the existing ones. The development of the blood vessel wall after the capillary formation discloses the efficient intercellular communication [10]. Tissue engineering and artificial organ development are also emerging fields that involve

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

• capillary forces (wet adhesion). The fluid can increase the contact area by filling minute cavities of micro- and nano-rough surfaces, where setae otherwise cannot adapt to, and prevents slipping of the foot due to its specific rheological properties [31][32][33][34][35]. It was demonstrated that the

• adhesive pads of spiders and geckos the humidity-related effects on adhesion can be explained by three different mechanisms: (1) capillary forces due to the formation of liquid bridges; (2) changes in the effective short-range interactions due to adsorbed monolayers of water on the substrate [11][14]; (3

• against it. The tarsal secretions in hairy attachment pads of beetles were found to be mainly lipid-based [22][26][27][49][50], with only a small volatile fraction (likely water) [30]. Peisker et al. [46] speculated that these secretions may have an additional function, apart from forming capillary

Functional diversity of resilin in Arthropoda

• Jan Michels,
• Esther Appel and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1241–1259, doi:10.3762/bjnano.7.115

• contribute to the adhesion efficiency of adhesive pads in the form of capillary interactions and cleaning effects. With regard to the resilin-dominated setal tips, an additional function is conceivable. As described above, resilin is only soft and flexible when it is hydrated. Accordingly, to keep the

Mesoporous hollow carbon spheres for lithium–sulfur batteries: distribution of sulfur and electrochemical performance

• Anika C. Juhl,
• Artur Schneider,
• Boris Ufer,
• Torsten Brezesinski,
• Jürgen Janek and
• Michael Fröba

Beilstein J. Nanotechnol. 2016, 7, 1229–1240, doi:10.3762/bjnano.7.114

• pores are blocked by sulfur and thus, are no longer accessible for nitrogen gas during the measurements. We believe that the strong capillary forces on liquids/melts in the mesopores are responsible for the pore blocking effect. Once sulfur has filled the mesopores there is no further driving force for

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• synthesis of endohedral CNTs (Figure 12c) is a physical modification in which the foreign atoms or molecules are inserted inside of the CNT by capillary action through defect sites [40]. The influence of the different functionalization methods on K1C values is shown in Figure 13. The smallest improvement

Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Gianluigi Zito,
• Teresa Cacace,
• Antigone Marino,
• José M. Otón and
• Morten A. Geday

Beilstein J. Nanotechnol. 2016, 7, 825–833, doi:10.3762/bjnano.7.74

• magnetically stirred at room temperature until toluene evaporation was complete. The LC cells are capillary filled. The impedance measurements require a small signal (<0.1Vrms) to obtain a linear system response. In this study, the effect of external electric fields must be included. Usually, the alternative

Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers

• Christian Ganser,
• Gerhard Fritz-Popovski,
• Roland Morak,
• Parvin Sharifi,
• Benedetta Marmiroli,
• Barbara Sartori,
• Heinz Amenitsch,
• Thomas Griesser,
• Christian Teichert and
• Oskar Paris

Beilstein J. Nanotechnol. 2016, 7, 637–644, doi:10.3762/bjnano.7.56

• water sorption isotherms measured for similar materials, indicating the different pressures for capillary condensation during adsorption and capillary evaporation during desorption, respectively, in pores with quite monodisperse size distributions [22]. It is well known that adsorption and desorption of

• filling/emptying (capillary condensation/evaporation) of the pores with water. Because the change of the relative humidity of air will also change its index of refraction (IOR), n, and the deflection read-out was done via a laser beam reflected from the cantilever, we have checked whether this can

• level of the individual pores can now be compared with the macroscopic cantilever deflection δ shown in Figure 2. Both quantities increase more gently at low RH, and become considerably steeper above 70%, where the onset of capillary condensation is expected. Indeed, the shape of the cantilever

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

• ]. However, the tapping phase is also affected by the intermittent formation of a capillary water neck between tip and sample as the cantilever oscillates, which can lead to either net attractive or net repulsive regimes depending on tapping amplitude, relative humidity, and local curvature of the tip and

• 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

• operating in the repulsive capillary force regime. Tip–surface capillary forces are most studied in the context of resonant cantilever motion instead of the slower, nonresonant distance modulation employed in PF-QNM. Nonetheless, our modulation amplitude (15 nm), measured tip radius (16–25 nm), and the

Single pyrimidine discrimination during voltage-driven translocation of osmylated oligodeoxynucleotides via the α-hemolysin nanopore

• Yun Ding and
• Anastassia Kanavarioti

Beilstein J. Nanotechnol. 2016, 7, 91–101, doi:10.3762/bjnano.7.11

• dA10dCdA9 is monitored by capillary electrophoresis (CE) analysis. Any side-reaction, or any backbone degradation, or oxidative damage would have been detectable as additional peaks with typical detectability of 0.1%. Any product formed by these processes is expected to retain some nucleotides, and

• pore we also tested the later with a dA25 tail added either to the 3’- or the 5’-end (Table 1). The oligos used in this study were purchased from Integrated DNA Technologies, as PAGE-purified and desalted materials (Table 1). They were analyzed by capillary electrophoresis (CE) to assess purity, and

• ) testable. Experimental Part A, Materials, oligos, preparation of osmylated oligos, capillary electophoresis (CE) analysis, and high performance liquid chromatography (HPLC) analysis: HPCE grade solution of 50 mM sodium tetraborate pH 9.3 was purchased from Agilent Technologies. A 4% aqueous osmium

pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• sample solutions were prepared in D2O. For quantitative NMR measurements of PDADMAC, a solution of resorcinol in D2O was used as an external standard. It was filled into a melting point capillary, which was flame-sealed on both ends and inserted on the central axis of an NMR tube containing the sample

Green synthesis, characterization and catalytic activity of natural bentonite-supported copper nanoparticles for the solvent-free synthesis of 1-substituted 1H-1,2,3,4-tetrazoles and reduction of 4-nitrophenol

• Akbar Rostami-Vartooni,
• Mohammad Alizadeh and
• Mojtaba Bagherzadeh

Beilstein J. Nanotechnol. 2015, 6, 2300–2309, doi:10.3762/bjnano.6.236

• NMR spectra were obtained on a Brucker Avance 90 MHz spectrometer, using tetramethylsilane (TMS) as an internal standard. The melting points were taken in open capillary tubes with a Büchi 510 melting point apparatus and were uncorrected. Thin-layer chromatography (TLC) was performed on silica gel

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

• forces (such as dispersion, electrostatic, magnetic), adhesive forces (such as chemical, capillary), viscoelastic forces, plastic forces, etc. For the case of viscoelasticity, in the most elaborate case one would need to solve the relaxation of the surface in 3D with the appropriate constitutive relation

Comprehensive characterization and understanding of micro-fuel cells operating at high methanol concentrations

• Aldo S. Gago,
• Juan-Pablo Esquivel,
• Neus Sabaté,
• Joaquín Santander and
• Nicolas Alonso-Vante

Beilstein J. Nanotechnol. 2015, 6, 2000–2006, doi:10.3762/bjnano.6.203

• ]. The use of a reference hydrogen electrode (RHE) allows one to studying the fuel crossover and the performance of the anode and the cathode, separately [19][20][21]. Unfortunately, this method requires the modification of the electrode compartments. On the other hand, through a Luggin capillary placed

• , in a simple and straightforward way, the performance of each electrode of a passive, air-breathing µDMFC, submitted to CH3OH up to 20 M. The stabilization and fuel consumption in the micro-system are also discussed. Results and Discussion E–I characteristics of the µDMFC The Luggin capillary was

• ) was achieved when adding 20 M CH3OH, but it lasted only 7.1 s as the fuel quickly poisoned the cathode. These observations were acquired by means of an RHE with a micro-capillary. It is simple and can be equally used for studying the performance of the anode and the cathode of other small fuel cells

Electrospray deposition of organic molecules on bulk insulator surfaces

• Antoine Hinaut,
• Rémy Pawlak,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2015, 6, 1927–1934, doi:10.3762/bjnano.6.195

• performed with a modified commercial MolecularSpray setup [33], of which a scheme is shown in Figure 1. The mixture of solvent and molecules is introduced by a syringe pump and a needle (1) into the first vacuum chamber (3) trough a capillary (2) by applying a bias of several kilovolts (1 to 5 kV). Behind

• the entrance capillary, three chambers (3, 4, 5) are used to pump solvent molecules and to reach the high vacuum level in the preparation chamber (7). The extra vacuum chamber (6) was added to further decrease the vacuum level during deposition, typical vacuum ranges are indicated in millibars. Two

• at an Ar+ pressure of p = 3 × 10−6 bar. The ESI setup (Figure 1) is connected to the UHV preparation chamber of the system. It is a commercial system from MolecularSpray [14][33]. After the spray is formed in air, highly charged droplets [49][50][51] enter by a capillary into the differential pumping

Temperature-dependent breakdown of hydrogen peroxide-treated ZnO and TiO₂ nanoparticle agglomerates

• Sinan Sabuncu and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 1897–1903, doi:10.3762/bjnano.6.193

• the temperature. The suspension was placed into a folded capillary cell for zeta potential measurement and the zeta potential of the NPs was measured at 30 °C. All experiments were performed at least three times. Results and Discussion Representative TEM images of the ZnO and TiO2 NPs are provided in

Two-phase equilibrium states in individual Cu–Ni nanoparticles: size, depletion and hysteresis effects

• Aram S. Shirinyan

Beilstein J. Nanotechnol. 2015, 6, 1811–1820, doi:10.3762/bjnano.6.185

• and foremost for pure materials) is the size-dependent melting temperature shift which is usually observed and explained in accordance to the so called capillary effect (surface-to-volume ratio or Laplace pressure) [1][2][3]. Somewhat less attention has been paid to binary and multicomponent

Continuum models of focused electron beam induced processing

• Milos Toth,
• Charlene Lobo,
• Vinzenz Friedli,
• Aleksandra Szkudlarek and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1518–1540, doi:10.3762/bjnano.6.157

• produced by a capillary-style gas injection system. We then cover simple continuum models that are valid in the reaction rate limited regime (where net adsorbate transport via surface diffusion is negligible) and can be used to model FEBIP performed using continuous and pulsed electron beams, physisorbed

• contributions from primary, backscattered and secondary electrons, each of which has a unique spatial profile and a unique energy distribution [19]. Gas flow from a capillary-style gas injection system (GIS) FEBIP precursor gases are injected into a specimen chamber using one of two methods. In the first method

• pressure gauges. However, in the vast majority of FEBIP setups, a gas injection capillary is used to inject the precursor gas into a chamber that is pumped continuously by a high-vacuum pumping system. The low conduction of the capillary makes it the element that limits the flow rate and shapes the flux

Stiffness of sphere–plate contacts at MHz frequencies: dependence on normal load, oscillation amplitude, and ambient medium

• Jana Vlachová,
• Rebekka König and
• Diethelm Johannsmann

Beilstein J. Nanotechnol. 2015, 6, 845–856, doi:10.3762/bjnano.6.87

• first category of problems originates from the numerous assumptions in the formulation of the model. For example, the normal pressure is assumed to stay constant during tangential loading. A second set of limitations is related to the idealized conditions. The CM model ignores roughness, capillary

• coefficients (determined from Δf(u0) and ΔΓ(u0)) is better in water than in air. We suspect that capillary forces affect ΔΓ(u0) stronger than Δf(u0). A more detailed discussion of the matter would require an extension of the Cattaneo–Mindlin model by specific contributions from different forces. Such an

Capillary and van der Waals interactions on CaF₂ crystals from amplitude modulation AFM force reconstruction profiles under ambient conditions

• Annalisa Calò,
• Oriol Vidal Robles,
• Sergio Santos and
• Albert Verdaguer

Beilstein J. Nanotechnol. 2015, 6, 809–819, doi:10.3762/bjnano.6.84

• attractive part of the force with relatively low noise and without missing information on critical ranges, particularly under ambient conditions where capillary interactions are believed to dominate. Thus a systematic study of the different profiles that may arise in such situations is still lacking. Here we

• employ the surfaces of CaF2, on which nanoscale water films form, to report on the range and force profiles that might originate by dynamic capillary interactions occurring between an AFM tip and nanoscale water patches. Three types of force profiles were observed under ambient conditions. One in which

• the force decay resembles the well-known inverse-square law typical of van der Waals interactions during the first 0.5–1 nm of decay, a second one in which the force decays almost linearly, in relatively good agreement with capillary force predicted by the constant chemical potential approximation

Applications of three-dimensional carbon nanotube networks

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

Beilstein J. Nanotechnol. 2015, 6, 792–798, doi:10.3762/bjnano.6.82

• wettability is well described by a Cassie–Baxter model [20] for which a quite rough surface allows air trapping and ensures the high contact angle measured. In particular, in such a system pores in the random network (i.e., void fraction) favor air trapping due to the strong capillary force that the surface

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

• Peter Guttmann and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 595–604, doi:10.3762/bjnano.6.61

• resolution needed for NEXAFS studies is provided by the monochromator in front of the condenser. Therefore, a spectral resolution E/ΔE in the range of 5000 which is comparable to STXM setups can be reached. The achromatic condenser is a novel ellipsoidal shaped capillary which has an efficiency one order of

• contrast transfer function (CTF) shows higher contrast values at medium to higher spatial frequencies [25][29]. Combining partial coherence with a high-resolution objective, the capillary optic of the HZB TXM leads to high contrast Cobject for nanoscale features which reduces artefacts of the measured

• pinhole close to the sample is necessary which acts together with the condenser as a monochromator. Schematic setup of the HZB-TXM for NEXAFS studies: Monochromatic X-rays are collected with an achromatic capillary condenser to illuminate the sample. At each photon energy a highly magnified 2D image of