Microfluidics as tool to prepare size-tunable PLGA nanoparticles with high curcumin encapsulation for efficient mucus penetration

• Nashrawan Lababidi,
• Valentin Sigal,
• Aljoscha Koenneke,
• Konrad Schwarzkopf,
• Andreas Manz and
• Marc Schneider

Beilstein J. Nanotechnol. 2019, 10, 2280–2293, doi:10.3762/bjnano.10.220

• mucus without air bubbles was labelled with 1 µL of AlexaFluor-wheat germ agglutinin. Afterwards, the stained mucus was placed in an imaging chamber made by nail polish on a cover slip resulting in an equally thick mucus layer [55]. At time zero, PLGA NPs were added on top of the mucus and z-stacks

Effects of surface charge and boundary slip on time-periodic pressure-driven flow and electrokinetic energy conversion in a nanotube

• Mandula Buren,
• Yongjun Jian,
• Yingchun Zhao,
• Long Chang and
• Quansheng Liu

Beilstein J. Nanotechnol. 2019, 10, 1628–1635, doi:10.3762/bjnano.10.158

• Economics, Hohhot, China 10.3762/bjnano.10.158 Abstract Time-periodic pressure-driven slip flow and electrokinetic energy conversion efficiency in a nanotube are studied analytically. The slip length depends on the surface charge density. Electric potential, velocity and streaming electric field are

• obtained analytically under the Debye–Hückel approximation. The electrokinetic energy conversion efficiency is computed using these results. The effects of surface charge-dependent slip and electroviscous effect on velocity and electrokinetic energy conversion efficiency are discussed. The main results

• show that the velocity amplitude and the electrokinetic energy conversion efficiency of the surface charge-dependent slip flow are reduced compared with those of the surface charge-independent slip flow. Keywords: electroviscous effect; energy conversion; nanofluidics; streaming potential; surface

Tailoring the stability/aggregation of one-dimensional TiO₂(B)/titanate nanowires using surfactants

• Atiđa Selmani,
• Johannes Lützenkirchen,
• Kristina Kučanda,
• Dario Dabić,
• Engelbert Redel,
• Ida Delač Marion,
• Damir Kralj,
• Darija Domazet Jurašin and
• Maja Dutour Sikirić

Beilstein J. Nanotechnol. 2019, 10, 1024–1037, doi:10.3762/bjnano.10.103

• electrolyte ions are bound as point charges, i.e., no charge distribution was considered. In the previous study a slip plane parameter was required to model the zeta potential [48]. In the present study, we were interested to see to what extent this parameter would change with the presence of the surfactant

• molecules and whether a constant slip plane parameter would allow the data to be described with different total surfactant concentrations. The final model nicely fits the experimental zeta potential data. In particular, when the total concentration of the surfactants are changed, the model describes the

• affinity for the nanowires. The binding of the 12-2-12 is clearly stronger. Interestingly, compared to the "ideal" slip plane parameter in the absence of surfactant, the slip plane distance is smaller by about 50% on average. If the slip plane in the absence of surfactant were to be mechanistically

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

• of geometry on friction forces on glass On the glass substrate, force–time plots of friction force (Figure 6) show that static friction (peak at phase V in Figure 6) is dominant over dynamic friction. Some sort of zigzag was typically visible in the dynamic friction regime, indicating stick-slip-like

• , medium-sized) was filled with demineralized water, and the microscopic glass slide was partially immersed for 20 mm in the bath in vertical direction. A plasma-treated glass cover slip was placed in the filled trough against one of the barriers in a diagonal orientation. The particle dispersion was added

• dropwise via the glass cover slip. Particles were added until a nearly packed monolayer was observed. Surface pressure was measured using a Wilhelmy plate. After complete evaporation of the ethanol was achieved, as confirmed by stabilization of the surface pressure, the monolayer was compressed by moving

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

• smooth surfaces, possibly being connected to the improved yield stress and slip resistance in this species. On the other hand, under certain conditions, more viscous fluids might also be able to reduce friction (e.g., because of reduced wetting properties). Hence, our conclusion remains a matter of

Hydrogen-induced plasticity in nanoporous palladium

• Markus Gößler,
• Eva-Maria Steyskal,
• Markus Stütz,
• Norbert Enzinger and
• Roland Würschum

Beilstein J. Nanotechnol. 2018, 9, 3013–3024, doi:10.3762/bjnano.9.280

• starvation [27]. This dislocation starvation also implies that the work hardening mechanism, which is based on dislocation interactions, is not active. However, current literature suggests that the active deformation mechanism in npAu is dislocation slip [28] and that dislocation starvation is not effective

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

• direction. The pull-off forces are much larger for the soft and very soft joint fibers than the stiff joint fibers. In the dragging phase, where the fibers start sliding with respect to the substrate, the fibers slide steadily without showing a stick–slip behavior as evidenced by the smooth shear force

Friction reduction through biologically inspired scale-like laser surface textures

• Johannes Schneider,
• Vergil Djamiykov and
• Christian Greiner

Beilstein J. Nanotechnol. 2018, 9, 2561–2572, doi:10.3762/bjnano.9.238

• effects) have a significant influence on the occurrence of stick–slip motion in biological systems and manufactured structures [21]. Baum et al. additionally focused on investigating the microstructure within the scales and aspects of mechanical interlocking between them. The same group of authors

• ], in our friction data, no sign of stick–slip phenomena were encountered. This discrepancy might be explained by the significantly different contact conditions (e.g., 10 mm sapphire ball vs 1 mm glass sphere) and sliding distances of several hundred meters vs 500 µm. Due to their small Young’s modulus

• , polymers are known the be more prone to stick–slip effects compared to ceramics and metals. This might be an additional explanation for the absence of stick–slip with these two counter body materials. Compared to our own previous work [23], we were able to significantly decrease friction forces in dry

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

• direct information on the crystal structure itself. Particularly when the FFM tip is subject to stick–slip advancement, this mode becomes especially efficient for resolving structural features. By mapping the power dissipated by these lateral forces, FFM can even detect such elusive structures as moiré

• qualitatively the tribological contact in terms of few atoms only, or even consider a single-atom contact. In this context, especially the concept of thermally-activated stick–slip [18] has become a universal starting point to describe nanoscopic friction phenomena. In recent years however, growing interest was

• nanoparticle stick–slip experiments [85][86], contact ageing was characterized as a thermally activated process [87]. Atomic-scale interface relaxations, either by single-atom displacements or by the formation and growth of commensurate patches at the interface [88], can serve as a likely explanation for the

Electromigrated electrical optical antennas for transducing electrons and photons at the nanoscale

• Arindam Dasgupta,
• Mickaël Buret,
• Nicolas Cazier,
• Marie-Maxime Mennemanteuil,
• Reinaldo Chacon,
• Kamal Hammani,
• Jean-Claude Weeber,
• Juan Arocas,
• Laurent Markey,
• Gérard Colas des Francs,
• Alexander Uskov,
• Igor Smetanin and
• Alexandre Bouhelier

Beilstein J. Nanotechnol. 2018, 9, 1964–1976, doi:10.3762/bjnano.9.187

• connected optical antenna is a Au constriction formed between two fan-out electrodes laying on a glass cover slip. We use electron-beam lithography and standard physical vapor deposition to produce gold constrictions and the proximity electrodes. The thickness of the Au layer is typically 50 nm, and we use

Friction force microscopy of tribochemistry and interfacial ageing for the SiO_x/Si/Au system

• Christiane Petzold,
• Marcus Koch and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2018, 9, 1647–1658, doi:10.3762/bjnano.9.157

• monitored during hold periods by recording normal and lateral force signals with an external data recorder (LTT24, Labortechnik Tasler GmbH, Würzburg, Germany). Atomic stick–slip events revealed that the system was drifting by about 1 atom per 10 s in direction of sliding in our experiments. Friction force

• in the range of 10–30 pN, while with SiOx/Si tips the friction was found to be ten times higher (Table 2). Irregular stick–slip signals were detected in the fast scan direction when probing oxidized Si(100) (Figure 1a) and regular stick–slip was detected for the fast scan direction on Au(111) (Figure

•  1b). For both surfaces a characteristic stick–slip distance in the range of the expected atomic distances (250 pm for Si(100); 170 pm for Au(111)) was observed reproducibly in subsequent scan frames. Larger scan frames recorded on Au(111) sometimes exhibited the herringbone reconstruction (Figure 1c

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

• -components of forces acting on Al and Pd atoms from the graphene atoms. The force Fs varies irregularly with time and has a sawtooth form, which is associated with stick-slip motion of the nanoparticle Figure 3. Figures for the characteristics of Al nanoparticles are represented in [17]. The dependence of

• the metallic clusters is much stronger (in particular for the Pd cluster) than the interaction potential between a metal atom and the graphene carbon atoms, it is likely that the ordered domains of metal atoms are not commensurate with the graphene lattice at any point during slip. Nevertheless

• , different orientations and positions of the particles on the graphene surface will generate different interaction energies with the graphene surface, and are the origin of the irregular stick-slip like motion of the nanoparticles [6][10][11][13][18][19][24][25]. Conclusion We have shown that the

Fatigue crack growth characteristics of Fe and Ni under cyclic loading using a quasi-continuum method

• Ren-Zheng Qiu,
• Yi-Chen Lin and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2018, 9, 1000–1014, doi:10.3762/bjnano.9.93

• at any orientation, the slip dislocation observed in the materials considerably affects the release of stress. Keywords: dislocations; fatigue crack growth; materials treatment effects; mechanics; shear stress; Introduction When materials undergo cyclic loading, the growth of cracks in the material

• changes in fatigue crack growth rates and crack opening displacements. Ma et al. [11] have examined the effect of orientation on the fatigue crack propagation in single-crystal iron under cyclic loading, leading to differences in the crack growth rates and slip directions. The plastic deformation and

• double slip in single-crystal Ni and Cu under different loading orientations, including [111], [100], [110] and [101], have been reported by Potirniche et al. [12]. In addition, the fatigue crack growth of body-centered cubic (BCC) metallic systems under cyclic loading was analyzed by some MD simulations

Scanning speed phenomenon in contact-resonance atomic force microscopy

• Christopher C. Glover,
• Jason P. Killgore and
• Ryan C. Tung

Beilstein J. Nanotechnol. 2018, 9, 945–952, doi:10.3762/bjnano.9.87

• scan speed and reported a phenomenological change in the observed forces when the scan speed was higher than a critical speed. Picco et al. [15] proposed two possible mechanisms for this observed effect: superlubricity and scan-speed dependence on the no-slip fluid boundary condition. Scan-speed

• has an effect on the friction [18][19]. Furthermore, this effect depends on the scan speed and can bring the system from a stick–slip state to a “steady sliding” state above a critical velocity [18]. It is noted that “a small viscous damping contribution in the tip–sample contact is sufficient enough

• to suppress stick–slip oscillations” [18]. It may be possible that the thin film acts as a source of viscous damping that allows the system to achieve a “steady sliding” state, above a critical velocity, which may have an effect on the CR measurements. The hydrodynamic lift force F varies

Perfusion double-channel micropipette probes for oxygen flux mapping with single-cell resolution

• Yang Gao,
• Bin Li,
• Riju Singhal,
• Adam Fontecchio,
• Ben Pelleg,
• Zulfiya Orynbayeva,
• Yury Gogotsi and
• Gary Friedman

Beilstein J. Nanotechnol. 2018, 9, 850–860, doi:10.3762/bjnano.9.79

• defined as no-slip walls. A negative pressure and a positive pressure was defined respectively on the top boundaries of the two channels to form the injection and extraction flow in the laminar flow module. The calculated flow field was then used as the flow parameters in the convection and diffusion

• defined as an oxygen reactor with reaction rate of 0.04 mol/m3s, which resulted in a total oxygen consumption rate of 10−17 mol/s. The boundaries of the reactor were set to be slip so that the flow velocity does not artificially set to zero. Simulations were run for tip–substrate distances varying from

Effect of microtrichia on the interlocking mechanism in the Asian ladybeetle, Harmonia axyridis (Coleoptera: Coccinellidae)

• Jiyu Sun,
• Chao Liu,
• Bharat Bhushan,
• Wei Wu and
• Jin Tong

Beilstein J. Nanotechnol. 2018, 9, 812–823, doi:10.3762/bjnano.9.75

• ° in the horizontal direction, respectively, which are very different from those in the HW1-elytron and HW1–HW2 (VS) interactions. The intersection of these two sets of microtrichia allows them to more easily slip past each other, which is consistent with CA test results showing that this region is

• the hindwings and therefore cannot slip out of the elytra, which means that the tergum will carry the elytra with the hindwings tucked inside. The intersegmental membrane can be stretched and shortened according to working conditions. The directional orientations of microtrichia in HW3 on the VS and

• maintained, and the hindwings will not slide out of the enclosed space when a disturbance occurs on the outside. In addition to helping retract the hindwings, the abdomen also moves along with the elytra during breathing and movement. Why do the hindwings not slip outside? When the elytra lift, the hindwings

Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces

• Sven Oras,
• Sergei Vlassov,
• Marta Berholts,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2018, 9, 660–670, doi:10.3762/bjnano.9.61

• violin bow hairs observed at nanoscale by AFM, may cause strong consequences at mascoscopic scale during the stick–slip phenomenon of the rubbing hairs surfaces and in fine such different acoustic outputs. Therefore, control of the nanoscale interactions between two surfaces through chemistry and contact

Electron interactions with the heteronuclear carbonyl precursor H₂FeRu₃(CO)₁₃ and comparison with HFeCo₃(CO)₁₂: from fundamental gas phase and surface science studies to focused electron beam induced deposition

• Ragesh Kumar T P,
• Paul Weirich,
• Lukas Hrachowina,
• Marc Hanefeld,
• Ragnar Bjornsson,
• Helgi Rafn Hrodmarsson,
• Sven Barth,
• D. Howard Fairbrother,
• Michael Huth and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2018, 9, 555–579, doi:10.3762/bjnano.9.53

Optimal fractal tree-like microchannel networks with slip for laminar-flow-modified Murray’s law

• Dalei Jing,
• Shiyu Song,
• Yunlu Pan and
• Xiaoming Wang

Beilstein J. Nanotechnol. 2018, 9, 482–489, doi:10.3762/bjnano.9.46

• channel and the parent channel and N is the branching number at every level), which is obtained under the assumption of no-slip conditions at the channel wall–liquid interface. However, at the microscale, the no-slip condition is not always reasonable; the slip condition should indeed be considered at

• some solid–liquid interfaces for the optimal design of the fractal tree-like channel network. The present work reinvestigates Murray’s law for laminar flow in a fractal tree-like microchannel network considering slip condition. It is found that the slip increases the complexity of the optimal design of

• the fractal tree-like microchannel network to achieve the minimum hydraulic resistance. The optimal diameter ratio to achieve minimum hydraulic resistance is not only dependent on the branching number, as stated by Murray’s law, but also dependent on the slip length, the level number, the length ratio

Patterning of supported gold monolayers via chemical lift-off lithography

• Liane S. Slaughter,
• Kevin M. Cheung,
• Sami Kaappa,
• Huan H. Cao,
• Qing Yang,
• Thomas D. Young,
• Andrew C. Serino,
• Sami Malola,
• Jana M. Olson,
• Stephan Link,
• Hannu Häkkinen,
• Anne M. Andrews and
• Paul S. Weiss

Beilstein J. Nanotechnol. 2017, 8, 2648–2661, doi:10.3762/bjnano.8.265

• with dye-labeled complementary strands (5′-AAA GAG GAG TTG ACA GTT GAG CTA ATG CCG ATT CTT GAG A/3AlexF488N/-3′). The samples were then imaged with the patterned side facing down in a drop of deionized water on a clean cover slip. The magnification and exposure time was adjusted appropriately for each

Interface conditions of roughness-induced superoleophilic and superoleophobic surfaces immersed in hexadecane and ethylene glycol

• Yifan Li,
• Yunlu Pan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2017, 8, 2504–2514, doi:10.3762/bjnano.8.250

• that can affect the drag of fluid flow. For surfaces with different oleophobicity, the boundary slip at the solid–oil interface is mostly larger than that at the solid–water interface. Roughness is a key factor for the wettability of superoleophilic/superoleophobic surfaces, and it has been found to

• affect the effective value of slip length in measurements. Moreover, there are no studies on the effect of roughness on slip at interfaces between oil and superoleophilic/superoleophobic surfaces. A theoretical description of the real surface roughness is yet to be found. Results show that the effective

• slip length is negative and decreases with an increasing root mean squared (RMS) roughness of surfaces, as the increasing roughness enhances the area with discontinuous slip at the solid–liquid interface. The underlying mechanisms are analyzed. The amplitude parameters of surface roughness could

Numerical investigation of the tribological performance of micro-dimple textured surfaces under hydrodynamic lubrication

• Kangmei Li,
• Dalei Jing,
• Jun Hu,
• Xiaohong Ding and
• Zhenqiang Yao

Beilstein J. Nanotechnol. 2017, 8, 2324–2338, doi:10.3762/bjnano.8.232

• conservation. For the purpose of facilitating modeling and analysis, the following assumptions were made: 1) The body force is considered negligible (e.g., gravity or magnetic force); 2) No slip of lubricant is supposed to occur on the boundary, which means the velocity of lubricant close to the friction pair

• this model. Figure 5 shows the meshed model of the micro-dimple unit with a total grid number of 416,670. Boundary conditions As shown in Figure 5, the upper and lower walls of the simulation model are set as no-slip boundaries. The upper wall moves along the positive direction of the y-axis with a

Photobleaching of YOYO-1 in super-resolution single DNA fluorescence imaging

• Joseph R. Pyle and
• Jixin Chen

Beilstein J. Nanotechnol. 2017, 8, 2296–2306, doi:10.3762/bjnano.8.229

• , immobilize, and image a single DNA using the established protocol and our fluorescence microscope. Glass cover slip substrates modified with amino silane are used to immobilize single DNA molecules (Figure 3). After surface modification, the water contact angle for the cover slips is 48 ± 4° which is

Molecular dynamics simulations of nanoindentation and scratch in Cu grain boundaries

• Shih-Wei Liang,
• Ren-Zheng Qiu and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2017, 8, 2283–2295, doi:10.3762/bjnano.8.228

• work, we analyzed the transverse and vertical grain boundaries for different angles. From the simulation results, it was found that the sample with a transverse grain boundary angle of 20° had a higher barrier effect on the slip band as compared to samples with other angles. Moreover, the

• interest. In this paper, the nanomechanical and grain boundary characteristics of Cu films were studied using MD simulations. The results are discussed in terms of the atomic trajectories, slip vectors, atomic flows, as well as the force and the average friction coefficients. Methodology The physical model

• , respectively. With the aim to observe the effect of the indentation and scratch grain boundaries on the atomic movement during dislocation, the diagram of the slip vector [30], which was applied to body-centered cubic (BCC), FCC, and hexagonal close packed (HCP) structures, was defined as where ns is the

Velocity dependence of sliding friction on a crystalline surface

• Christian Apostoli,
• Giovanni Giusti,
• Jacopo Ciccoianni,
• Gabriele Riva,
• Rosario Capozza,
• Rosalie Laure Woulaché,
• Andrea Vanossi,
• Emanuele Panizon and
• Nicola Manini

Beilstein J. Nanotechnol. 2017, 8, 2186–2199, doi:10.3762/bjnano.8.218

• cantilever. In that scheme a stick-slip to smooth-sliding transition can also be investigated, especially at low speed (see Appendix “The static friction force”), allowing one to study in detail the nonlinear phenomena and mechanisms of phonon excitations that arise at slip times. The stick-slip regime and

• -slip process repeats itself. Conversely, if vpull is less than a certain critical value vpull c, the whole chain speed advances at a speed asymptotically close to vpull: the support, the slider, and the chain slide together at the same velocity and the spring never elongates enough for the elastic