Bio-inspired micro-to-nanoporous polymers with tunable stiffness

• Julia Syurik,
• Ruth Schwaiger,
• Prerna Sudera,
• Stephan Weyand,
• Siegbert Johnsen,
• Gabriele Wiegand and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2017, 8, 906–914, doi:10.3762/bjnano.8.92

• storage modulus; Introduction Functional adaptation through porous structures is widely present in nature [1]. Natural structures are often made of hierarchical porous networks, serving mainly for passive mechanical functions [1][2][3], but also for capillary channels and membranes [1]. Nature offers

Functional dependence of resonant harmonics on nanomechanical parameters in dynamic mode atomic force microscopy

• Federico Gramazio,
• Matteo Lorenzoni,
• Francesc Pérez-Murano,
• Enrique Rull Trinidad,
• Urs Staufer and
• Jordi Fraxedas

Beilstein J. Nanotechnol. 2017, 8, 883–891, doi:10.3762/bjnano.8.90

• with a well-defined radius R. For simplicity neither viscoelastic nor capillary forces have been considered. The negligible contribution of viscoelastic forces in PS with 25 N/m cantilevers is discussed in the Supporting Information File 1 (see Figure S3). Experimental AFM experiments have been

Measuring adhesion on rough surfaces using atomic force microscopy with a liquid probe

• Juan V. Escobar,
• Cristina Garza and
• Rolando Castillo

Beilstein J. Nanotechnol. 2017, 8, 813–825, doi:10.3762/bjnano.8.84

• nanometer-sized peaks commonly used for the determination of AFM tip sharpness and a multi-scaled rough diamond surface containing sub-micrometer protrusions. Measurements are carried out in a nitrogen atmosphere to avoid water capillary interactions. We obtain information about the average force of

• the colloidal particle on a tipless cantilever. The force required to pull the drop off a surface is measured in a nitrogen atmosphere to avoid water capillary interactions. The liquid probe is close to what would be expected to be a smooth probe down to the atomic level. Recently, we reported an

• be able to compare the value with published data. In this case, we obtain Fadh = 48.5 ± 0.1 nN (kc = 0.346 N/m). The measured Fadh in air is close to the value measured in vacuum, revealing the low humidity of our ambient conditions because forces of capillary origin seem to be negligible. Leite et

First examples of organosilica-based ionogels: synthesis and electrochemical behavior

• Andreas Taubert,
• Ruben Löbbicke,
• Barbara Kirchner and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2017, 8, 736–751, doi:10.3762/bjnano.8.77

• IV isotherm typical of mesoporous solids. The H2 hysteresis loop is due to capillary condensation in the mesopores and is attributed to differences between condensation and evaporation processes occurring in pores with narrow necks and wide cavities often referred to as ink bottle pores. The late

Vapor deposition routes to conformal polymer thin films

• Priya Moni,
• Ahmed Al-Obeidi and
• Karen K. Gleason

Beilstein J. Nanotechnol. 2017, 8, 723–735, doi:10.3762/bjnano.8.76

•  1a) or capillary bridge formation over a feature (Figure 1b). By contrast, vapor phase techniques are controlled by the individual adsorption of small molecules and their subsequent surface reaction to form a polymer film. In this case, the only interaction energy of concern is between the molecule

• wetting properties of capillary pore membranes, as seen in Figure 7c [4]. To determine the coating conformality, electron microprobe analysis (EMPA) was used to measure the fluorine signal down the pore wall of a coated membrane and presented in Figure 7d. While the fluorine signal is detected at the

• ) on a commercial sponge using iCVD [46]. Figure 9b shows the iCVD coating conformally covering the sponge’s microstructure. Previously, Lau et al. demonstrated conformal coverage of iCVD grown fluoropolymers on vertically aligned carbon nanotube (CNT) forests to prevent capillary densification as seen

Dispersion of single-wall carbon nanotubes with supramolecular Congo red – properties of the complexes and mechanism of the interaction

• Anna Jagusiak,
• Barbara Piekarska,
• Tomasz Pańczyk,
• Małgorzata Jemioła-Rzemińska,
• Elżbieta Bielańska,
• Barbara Stopa,
• Grzegorz Zemanek,
• Janina Rybarska,
• Irena Roterman and
• Leszek Konieczny

Beilstein J. Nanotechnol. 2017, 8, 636–648, doi:10.3762/bjnano.8.68

• -like structures formed in 2 mg/mL and 5 mg/mL solutions. The analysis was performed using NANO DSC Series III System (model 6300) with Platinum Capillary Cell (TA Instruments) equipped with Nano DSCRun software. In order to avoid the formation of air bubbles during the heating, the samples were

• degassed for 10–15 min before the measurement using the negative pressure of 0.3–0.5 atm. A reference chamber was filled with a buffer used for the analysed sample. All the measurements were performed at 3 bar pressure in a 0.33 mL capillary cell. Data was collected in the range of 10–90 °C at 1 °C·min−1

Formation and shape-control of hierarchical cobalt nanostructures using quaternary ammonium salts in aqueous media

• Ruchi Deshmukh,
• Anurag Mehra and
• Rochish Thaokar

Beilstein J. Nanotechnol. 2017, 8, 494–505, doi:10.3762/bjnano.8.53

• or by thermal decomposition [18]. An alternative way to obtain complex hierarchical nanostructures is the controlled assembly of primary building blocks using electric and magnetic forces, capillary effects, and surface defects. Fascinating shapes such as, rice grain-like structures were formed by

Fiber optic sensors based on hybrid phenyl-silica xerogel films to detect n-hexane: determination of the isosteric enthalpy of adsorption

• Jesús C. Echeverría,
• Ignacio Calleja,
• Paula Moriones and
• Julián J. Garrido

Beilstein J. Nanotechnol. 2017, 8, 475–484, doi:10.3762/bjnano.8.51

• in the molar percentage of PhTEOS in the mixture of silicon precursors. As the percentage of PhTEOS increased, the position of the capillary condensation step shifted towards higher relative pressure, indicating an increase in pore size. The hysteresis loops did not close at p/pº of 0.42, as is

Microfluidic setup for on-line SERS monitoring using laser induced nanoparticle spots as SERS active substrate

• Oana-M. Buja,
• Ovidiu D. Gordan,
• Nicolae Leopold,
• Andreas Morschhauser,
• Jörg Nestler and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2017, 8, 237–243, doi:10.3762/bjnano.8.26

• of residues of malachite green (MG) using surface-enhanced Raman scattering (SERS) is reported. The SERS active substrate was prepared via laser induced synthesis of silver or gold nanoparticles spot on the bottom of a 200 μm inner dimension glass capillary, by focusing the laser beam during a

• detection of the analyte, as shown schematically in Figure 1a. SERS monitoring of MG adsorbed on silver nanoparticle spots The synthesis of the SERS active silver nanoparticles spot was carried out by laser-induced spot synthesis [24] inside the glass capillary. The silver nitrate and sodium citrate

• solution was injected in a continuous flow into the microfluidic capillary while the laser beam (λ = 514.7 nm) was focused on the bottom part of the capillary. As illustrated in the schematic diagram in Figure 1a, the exposure of the silver/citrate mixture to the laser beam causes the photoinduced

Structural and tribometric characterization of biomimetically inspired synthetic "insect adhesives"

• Matthias W. Speidel,
• Malte Kleemeier,
• Andreas Hartwig,
• Klaus Rischka,
• Angelika Ellermann,
• Rolf Daniels and
• Oliver Betz

Beilstein J. Nanotechnol. 2017, 8, 45–63, doi:10.3762/bjnano.8.6

• adhesive fluids produced by glandular systems underlying the adhesive cuticular structures [2][3][4]. One major function of these liquid adhesives is to wet and maximize the contact area with the substrate by filling its surface irregularities [5][6]. In addition, viscous and capillary forces are conveyed

Streptavidin-coated gold nanoparticles: critical role of oligonucleotides on stability and fractal aggregation

• Roberta D'Agata,
• Pasquale Palladino and
• Giuseppe Spoto

Beilstein J. Nanotechnol. 2017, 8, 1–11, doi:10.3762/bjnano.8.1

• or 0.22 µm pore size membrane. Samples (1 mL) were transferred into a disposable polystyrene cuvette for DLS measurements while a folded capillary cell was used for ζ-potential measurements. The concentration of solutions (0.1–1 nM) was adjusted to accommodate scattering properties of samples and

When the going gets rough – studying the effect of surface roughness on the adhesive abilities of tree frogs

• Niall Crawford,
• Thomas Endlein,
• Jonathan T. Pham,
• Mathis Riehle and
• W. Jon P. Barnes

Beilstein J. Nanotechnol. 2016, 7, 2116–2131, doi:10.3762/bjnano.7.201

• capillary and viscosity forces between the pad and the surface [1][2][3]. The polygonal epithelial cells (approx. 10 µm in diameter) are covered with nanostructures, which are thought to create friction by direct contact with the surface [3]. The combination of the fluid filled adhesive area and the

• specialised morphology allow the tree frogs to climb smooth vertical and overhanging surfaces. The attachment ability of tree frogs is affected by both surface chemistry and surface roughness. Hydrophobic leaves (such as those on lotus leaves [4]), could affect the capillary forces produced by the pad (which

• capillary forces will be reduced due to a decline in the Laplace pressure component of capillarity [7]. Bhushan’s ‘submerged‘ regime is that of a rock/torrent frog climbing water-covered rock, where the toe pads are completely submerged, thus abolishing any meniscus [8]. In such cases, capillary forces will

Annealing-induced recovery of indents in thin Au(Fe) bilayer films

• Anna Kosinova,
• Ruth Schwaiger,
• Leonid Klinger and
• Eugen Rabkin

Beilstein J. Nanotechnol. 2016, 7, 2088–2099, doi:10.3762/bjnano.7.199

• processes in the material controlled by capillary forces [10][11] or the interaction of defects [12]. The healing capability of defects was recently demonstrated for Au [13] and Fe [14] nanoparticles. It was shown that the controlled injection of dislocations into single-crystalline faceted metal

Solvent-mediated conductance increase of dodecanethiol-stabilized gold nanoparticle monolayers

• Patrick A. Reissner,
• Jean-Nicolas Tisserant,
• Antoni Sánchez-Ferrer,
• Raffaele Mezzenga and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 2057–2064, doi:10.3762/bjnano.7.196

• for 10 s. From Figure 4, we can conclude that the compaction process is completed within one hour. This excludes that capillary forces originating from a drying solvent meniscus cause the compaction of the monolayer, because it would be independent of the immersion duration. The observed time

Chitosan-based nanoparticles for improved anticancer efficacy and bioavailability of mifepristone

• Huijuan Zhang,
• Fuqiang Wu,
• Yazhen Li,
• Xiping Yang,
• Jiamei Huang,
• Tingting Lv,
• Yingying Zhang,
• Jianzhong Chen,
• Haijun Chen,
• Yu Gao,
• Guannan Liu and
• Lee Jia

Beilstein J. Nanotechnol. 2016, 7, 1861–1870, doi:10.3762/bjnano.7.178

• Corporation., Milford, MA, USA) was operated in positive mode and equipped with an electrospray ionization (ESI) source. The main operating parameters were optimized as follows: desolvation gas (nitrogen) 600 L/h, cone gas (nitrogen) 50 L/h, collision gas (argon) about 0.15 MPa, cone voltage 30 V, capillary

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