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

• larger size range of droplets as shown by the bright field/fluorescence microscopic images in comparison with those by cryo-SEM. The microscopic analyses revealed that the first generation provided a broader droplet size range with extremely large individual droplets leading to platykurtic kurtosis

• all other emulsions, those based on octacosane featured polyhedral droplets, which had a crystal-like appearance (Figure 1e,f; Supporting Information File 1, Figure S1a,b,f). In addition, in two out of three cases, the presence of octacosane led to unstable phases and to the formation of clumps within

• , displayed fluorescent droplets only thereby indicating the presence of oil-in-water (o/w) emulsions (Figure 1a,c; Supporting Information File 1, Table S1; Figure S2a,e,g). Vice versa, the two emulsions SA4 and SG4 possessed a fluorescent outer phase surrounding non-fluorescent droplets thus indicating the

From iron coordination compounds to metal oxide nanoparticles

• Mihail Iacob,
• Carmen Racles,
• Codrin Tugui,
• George Stiubianu,
• Adrian Bele,
• Liviu Sacarescu,
• Daniel Timpu and
• Maria Cazacu

Beilstein J. Nanotechnol. 2016, 7, 2074–2087, doi:10.3762/bjnano.7.198

• using the STAR software from Mettler Toledo. The transmission electron microscopy (TEM) images were taken using a dedicated HITACHI HT7700 microscope operating in high contrast mode at 100 kV accelerating voltage. The samples were prepared by placing small droplets of the diluted dispersion (≈1 g/L) of

Prediction of the mechanical properties of zeolite pellets for aerospace molecular decontamination applications

• Guillaume Rioland,
• Patrick Dutournié,
• Delphine Faye,
• T. Jean Daou and
• Joël Patarin

Beilstein J. Nanotechnol. 2016, 7, 1761–1771, doi:10.3762/bjnano.7.169

• decontamination; operating optimums; zeolite pellets; Introduction Molecular contamination is of great concern in aerospace-based applications. Once satellites are in orbit, molecules contained in paints, adhesives or glues can outgas and form films or droplets on the surface of mirrors, lenses, solar cells or

Sb₂S₃ grown by ultrasonic spray pyrolysis and its application in a hybrid solar cell

• Erki Kärber,
• Atanas Katerski,
• Ilona Oja Acik,
• Arvo Mere,
• Valdek Mikli and
• Malle Krunks

Beilstein J. Nanotechnol. 2016, 7, 1662–1673, doi:10.3762/bjnano.7.158

• (CSP) is a simple and fast method in which a solution of precursor materials is pulverized and the aerosol is then guided by flow of carrier gas onto a hot substrate. The droplets can be produced pneumatically, or, ultrasonically with a piezoelectric generator submerged in the solution bath. The

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

• investigated by measuring static/dynamic CAs (θS, θA, and θR) of water and n-hexadecane droplets. As shown in Table 1, they were found to be strongly dependent on both surface chemical and topographical properties. Water CA measurements confirmed that the glass, Si and VUV-Never Wet surfaces were

• superhydrophilic with θS close to zero, while the other five surfaces exhibited either hydrophobic (ODS, FAS17 and C10-hybrid surfaces; water CAs greater than 100°) or superhydrophobic (Never Wet and Soot-TMOS-FAS17Cl surfaces; water CAs larger than 150°) properties. Water droplets on the latter surfaces moved

• hysteresis of water on the hybrid film was also low (Δθ = 8°, the lowest of the smooth surfaces). Thus, contrasting with the smooth ODS and FAS17 monolayer surfaces, water droplets similarly slid off the C10-hybrid surfaces at low tilt angles, regardless of the magnitude of their static/dynamic CAs [10][36

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

• with a complex surface topology to study the shape of a liquid drop in advancing and receding wetting scenarios. More specifically, we study droplets on an inverse opal: spherical cavities in a hexagonal pattern. In line with experimental data, we find that the surface may switch from hydrophilic

• free energy in the system when there is a very thick adsorbed layer at the surface. Hence, we can obtain contact angle information without explicitly generating droplets. In passing we mention that for not too small droplets the contact angle as obtained by a three-gradient analysis (as used below

• binodal. Curved L/V interfaces: Kelvin and Laplace Macroscopic droplets (with negligible curvature) cannot be generated using our method. As the system size is limited, our drops have L/V interfaces that are typically strongly curved. The thermodynamics of curved interfaces is well understood, but there

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

• contributions from viscous forces could be expected [31][53]. For C. septempunctata, viscosity of the tarsal secretion was found to be of order 20 mPa·s [31] and droplets of volumes around 1 fL of the tarsal secretion made contact angles smaller than 10° with freshly cleaved mica surfaces (calculation based on

• droplets of water that are crucial for the function of the adhesive system [28]. The reduction in traction forces observed in the present study at 99% RH (without visible water condensation) may be explained by a sufficient amount of adsorbed water on the substrate. It has been shown that the friction

Ammonia gas sensors based on In₂O₃/PANI hetero-nanofibers operating at room temperature

• Qingxin Nie,
• Zengyuan Pang,
• Hangyi Lu,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

• excess of PANI covering. Figure 3a,b shows SEM images of In(NO3)3/PVP composite nanofibers and In2O3 nanofibers, respectively. From Figure 3a, it can be seen that the surface of In(NO3)3/PVP composite nanofibers was relatively smooth and no beads and droplets appeared. The diameter distribution of In(NO3

Time-dependent growth of crystalline Au⁰-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica

• Liz M. Rösken,
• Felix Cappel,
• Susanne Körsten,
• Christian B. Fischer,
• Andreas Schönleber,
• Sander van Smaalen,
• Stefan Geimer,
• Christian Beresko,
• Georg Ankerhold and
• Stefan Wehner

Beilstein J. Nanotechnol. 2016, 7, 312–327, doi:10.3762/bjnano.7.30

• been found [65][66]. Structures inside the vegetative cells, like the thylakoid membranes, at which photosynthesis takes place, and electron dense spots, most probably representing lipid droplets, are visible by TEM. The extracellular polymeric substances (EPS) on the outside of the vegetative cell are

Two step formation of metal aggregates by surface X-ray radiolysis under Langmuir monolayers: 2D followed by 3D growth

• Smita Mukherjee,
• Marie-Claude Fauré,
• Michel Goldmann and
• Philippe Fontaine

Beilstein J. Nanotechnol. 2015, 6, 2406–2411, doi:10.3762/bjnano.6.247

• the 3D structures, which are then thicker than the X-ray penetration depth. Experimental The sample preparation procedure was previously described in detail [4][8]. Droplets of 5 mmol·L−1 of behenic acid solution (C21H43COOH, Sigma-Aldrich) in chloroform (CHCl3) were spread onto the silver-ion

Self-organization of gold nanoparticles on silanated surfaces

• Htet H. Kyaw,
• Salim H. Al-Harthi,
• Azzouz Sellai and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2015, 6, 2345–2353, doi:10.3762/bjnano.6.242

• tensiometer (Biolin Scientific, Sweden). 5 µL water droplets were used and water contact angle was measured at five random locations on each sample surface. X-ray photoelectron spectroscopy (XPS) measurements were carried out using Omicron Nanotechnology system with Al Kα radiation (1486.6 eV). All XPS

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

• ) is short compared to the charge compensation time (days), a charged surface is obtained. In our setup, a positive bias is applied to the solution containing the diporphyrin molecules. Therefore, droplets produced during ESI as well as the molecules reaching the surface are positively charged. This

• 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

• system composed of the three chambers separated by leak orifices. During this differential pumping system, initial droplets undergo successive droplet solvent pumping and coulomb fission leading to ionized molecules only. The spray quality in air was controlled during deposition with a camera. The base

Template-controlled mineralization: Determining film granularity and structure by surface functionality patterns

• Nina J. Blumenstein,
• Jonathan Berson,
• Stefan Walheim,
• Petia Atanasova,
• Johannes Baier,
• Joachim Bill and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2015, 6, 1763–1768, doi:10.3762/bjnano.6.180

• with the acid for 30 s and gently dried in a nitrogen flow. This procedure was repeated two times with fresh solvent. The fluorinated SAM was deposited from the gas phase: The samples were positioned face down at the lid of a desiccator containing two droplets of 1H,1H,2H,2H-perfluorodecyl

Conductance through single biphenyl molecules: symmetric and asymmetric coupling to electrodes

• Karthiga Kanthasamy and
• Herbert Pfnür

Beilstein J. Nanotechnol. 2015, 6, 1690–1697, doi:10.3762/bjnano.6.171

• ’-biphenyl]-4-carbonitrile (M2) in toluene. The chemical structures are shown in Figure 2. Droplets of solutions of the molecules were put on the gold electrodes and dried before inserting them into vacuum. The same procedure was applied to gold thin films (100 nm) thermally evaporated onto silicon

• by a factor of three, although the concentration in solution was ten times higher. With the MCBJ we use a few droplets of molecular solution. The solvent evaporated within one to two minutes in air. Therefore, the surface concentration will be much smaller and we expect only few molecules at the

Peptide-equipped tobacco mosaic virus templates for selective and controllable biomineral deposition

• Klara Altintoprak,
• Axel Seidenstücker,
• Alexander Welle,
• Sabine Eiben,
• Petia Atanasova,
• Nina Stitz,
• Alfred Plettl,
• Joachim Bill,
• Hartmut Gliemann,
• Holger Jeske,
• Dirk Rothenstein,
• Fania Geiger and
• Christina Wege

Beilstein J. Nanotechnol. 2015, 6, 1399–1412, doi:10.3762/bjnano.6.145

• was carried out to determine the silica shell thickness of TMV–KD10 particles after different reaction times. 3 µL of mineralized TMV particles in solution were incubated on a 400-mesh formvar, carbon-covered copper grid for 5 min. The droplet was removed with five droplets of ultrapure water and air

The Kirkendall effect and nanoscience: hollow nanospheres and nanotubes

• Abdel-Aziz El Mel,
• Ryusuke Nakamura and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 1348–1361, doi:10.3762/bjnano.6.139

• that the nanodroplet tends to split into multiple tiny dewetting metal bismuth nanodroplets. The droplets then migrate and aggregate on the curved inner surface of the oxide shell before the bismuth wets the surface again (between 410.4 and 413.6 s). They attributed this reversible wetting transition

Polymer blend lithography for metal films: large-area patterning with over 1 billion holes/inch²

• Cheng Huang,
• Alexander Förste,
• Stefan Walheim and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2015, 6, 1205–1211, doi:10.3762/bjnano.6.123

• polystyrene (PS) and poly(methyl methacrylate) (PMMA), dissolved in methyl ethyl ketone (MEK) is used. This system forms a purely lateral structure on the substrate at controlled humidity, which means that PS droplets are formed in a PMMA matrix, whereby both phases have direct contact both to the substrate

• dissolution, either the PMMA matrix (see Figure 1b, PMMA marked in red) or the PS droplets (see Figure 1g, PS marked in blue) can be kept on the substrate for the lithographic application. After the deposition of metal by thermal evaporation, the desired metal covers the whole surface of the sample (see in

• . Figure 1e is an SEM image taken at a tilting angle of 45° of a polymer lithographic mask, which is schematically shown in Figure 1b. After the polymer blend film was rinsed in cyclohexane, the PS droplets were dissolved and a perforated PMMA film with holes was left on the silicon substrate. The

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• ]. Figure 1b shows a photograph of the laser-generated gold and silver nanoparticle dispersions fabricated by the LAL technique. Droplets of the nanoparticle colloidal solution were placed on a polished silicon substrate. These droplets were dried and the nanoparticles on the silicon substrate were

Structure and mechanism of the formation of core–shell nanoparticles obtained through a one-step gas-phase synthesis by electron beam evaporation

• Andrey V. Nomoev,
• Sergey P. Bardakhanov,
• Makoto Schreiber,
• Dashima G. Bazarova,
• Nikolai A. Romanov,
• Boris B. Baldanov,
• Bair R. Radnaev and
• Viacheslav V. Syzrantsev

Beilstein J. Nanotechnol. 2015, 6, 874–880, doi:10.3762/bjnano.6.89

• than that of Cu (Tb(Si) = 3538 K, Tb(Cu) = 2835 K) as is the surface tension. It is reasonable to assume that as the mixed vapour cools, droplets of Cu and Si condense from the gas phase and come into contact. In the aggregated droplets, the silicon atoms will segregate to the surface of the droplet

• form the shell; the amorphous nature resulting from the SiO2. This solid shell around the liquid copper allows the Cu to crystallize undisturbed from the outer atmosphere; forming multiple contact twinned structure instead of polycrystals. Excess Si and Cu which did not form into mixed droplets may

• later agglomerate onto the shell surface; the adsorbed copper oxidizing when the powder is exposed to air. Particles with moiré patterns may form when insufficient Si droplets mix with Cu; leaving uncovered areas on the copper that could be oxidized. The variations in the particle sizes of the Cu@silica

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

• reconstructed force curve of Figure 2a a step-like discontinuity that could be associated with the formation of a capillary bridge is not distinguishable. Instead, a slow decay is observed in the force at a distance, 2.33 nm, that approximately matches the sum of the height of the absorbed water droplets on top

• nanoparticle and a flat plate [47]. Finally notice that, due to the imaging conditions (see Experimental section), the apparent height of the water droplets/layers measured by AFM topography (Figure 1a and Figure 1b) should be equal or close to the true value as water perturbation due to mechanical contact is

• ) Experimental normalized Fts, Ediss and ΔΦ curves vs dmin collected on a CaF2 sample containing water droplets (a) and on a water patch on top of the CaF2 crystal (c). FAD = 2.8 nN, Emax = 82 eV, ΔΦmax = 11.0° in (a) and FAD = 2.0 nN, Emax = 114 eV, ΔΦmax = 13.9° in (c) (see main text). A0 in (a) and (c) is 23

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

• hydrophobicity one can measure the advanced static contact angle at room temperature for water droplets of different volumes ranging from 5 to 20 µL, as shown in Figure 4a. The presence of a composite solid–liquid–air interface explains the high value of the measured contact angle (Θ = 175°), as evaluated in

• junctions between CNTs. Electron energy loss spectra (Ep = 300 eV) obtained on the CNT-sponge. The π and π + σ plasmons have been emphasized for better view (red line). Photographs of water droplets of different volumes (a) and contact angle profile of a single drop (b) on the bulk material. Stability of

Hematopoietic and mesenchymal stem cells: polymeric nanoparticle uptake and lineage differentiation

• Ivonne Brüstle,
• Thomas Simmet,
• Gerd Ulrich Nienhaus,
• Katharina Landfester and
• Volker Mailänder

Beilstein J. Nanotechnol. 2015, 6, 383–395, doi:10.3762/bjnano.6.38

• chondrogenic differentiation, the alkaline phosphatase activity for the osteogenic differentiation, as well as the lipid droplets for the adipogenic differentiation showed the same characteristics as the sample without nanoparticles. To investigate if the presence of polymeric nanoparticles can induce

• was performed. In the case of adipogenic differentiation, lipid droplets could be visualized with Oil-red O, the extracellular matrix developing during chondrogensis could be detected with methylene blue staining and, in the case of osteogenic differentiation, the activity of alkaline phosphatase was

• was detected by staining with Loeffler´s methylene blue (Carl Roth, Karlsruhe, Germany). Adipogenic differentiation was detected by the lipophilic dye Oil Red O (Sigma Aldrich), which stained the lipid droplets of adipocytes deep red. Hematoxylin–Harris was used for counter staining which stained the

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

• SWCNT films. Moreover, in Figure 3a and Figure 3b, images of water droplets cast on our SWCNT and MWCNT films are shown, with average contact angle values of θ = 110 ± 3° and θ = 97 ± 8°, respectively. These results can be ascribed to the particular morphology of both the films induced by the inherent

• the contact angle is due to the highly rough and porous surface of our samples. In addition, no roll-off angle value could be measured, evidently due to the high contact angle hysteresis, which pinned the droplets to the surface [2]. In order to better understand the origin of the enhancement provided

• carbon nanotube. Indeed, on our carbon nanotube films no contact angle (θ ≈ 0) can be measured for pure ethanol droplets. Therefore, we investigated all the wetting phenomena occurring on our carbon nanotube surface, exploring all the wetting states. We further noted that for θ ≈ 56°, (cos θ ≈ 0.56

Release behaviour and toxicity evaluation of levodopa from carboxylated single-walled carbon nanotubes

• Julia M. Tan,
• Jhi Biau Foo,
• Sharida Fakurazi and
• Mohd Zobir Hussein

Beilstein J. Nanotechnol. 2015, 6, 243–253, doi:10.3762/bjnano.6.23

• slides and detailed scans were performed in the 100–2000 cm−1 range. The nanotube product was first ultrasonicated in ethanol using a PowerSonic 420 (Hwashin Technology Co., Korea) device. Several droplets of the nanotube suspension were deposited onto a glass slide and then air dried at room temperature

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

• /m. Considering these extremely stiff cells at high CTAB coated gold nanorods concentrations as liquid droplets is probably no longer justified. It is difficult to explain these extraordinary high values in terms of cortical or even membrane tension and inextensibility of the plasma membrane alone