Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• -defined assemblies, which was found to obey to the same rules as for molecular assembly [30]. The tunability of the surface-active properties of particles with a segregated corona over particles with a uniform wettability enables access to an even greater extent of asymmetry, as known from natural

Electrical contacts to individual SWCNTs: A review

• Wei Liu,
• Christofer Hierold and
• Miroslav Haluska

Beilstein J. Nanotechnol. 2014, 5, 2202–2215, doi:10.3762/bjnano.5.229

• air as the gate dielectric) was obtained for a device fabricated on a suspended SWCNT using a 3 µm air gap as the dielectric material between the gate electrode and the transistor channel. Contact metal Work function and wettability: The presence of a Schottky barrier at the metal–SWCNT contact

• [56]. Other than the work function differences between the metals and the SWCNTs, the wettability of metals to SWCNTs is another critical factor affecting the contact properties. Although Au and Pd have comparable work functions (shown in Table 1), Au–CNT contacts possess a higher on-resistance in

• most cases. This can be explained by the relatively poor wettability of gold to SWCNTs. As shown in Figure 7a, discrete Au nanoparticles are formed on suspended SWCNTs [57]. In contrast, Pd forms a nearly continuous coating on the SWCNT [57], which indicates a good adhesion to the sidewall of carbon

Topology assisted self-organization of colloidal nanoparticles: application to 2D large-scale nanomastering

• Hind Kadiri,
• Serguei Kostcheev,
• Daniel Turover,
• Rafael Salas-Montiel,
• Komla Nomenyo,
• Anisha Gokarna and
• Gilles Lerondel

Beilstein J. Nanotechnol. 2014, 5, 1203–1209, doi:10.3762/bjnano.5.132

• . First, we used only water as a solvent, but the drop did not cover the entire surface due to hydrophobicity. Hence, we decided to replace water by ethanol thereby increasing the wettability of the surface. With only ethanol, we were able to cover the entire surface, but the overall structure was not

• governed by the liquid flow. In the case of the patterned substrate, the flux of particles became slower because the wettability of the surface increases with the presence of the patterning. As a consequence, there is a good dispersion of the beads on the patterned substrate, resulting in a regular

The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review

• Yunlu Pan,
• Bharat Bhushan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117

• this review, the influence of an applied voltage on the surface wettability, nanobubbles, surface charge density and slip length are discussed. The contact angle (CA) and contact angle hysteresis (CAH) of a droplet of deionized (DI) water on a hydrophobic polystyrene (PS) surface were measured with

• liquid, surface wetting, surface charge, nanobubbles and boundary slip are believed to affect the drag of liquid flow [3][4][5][6][7][8][9][10]. By applying a voltage to the system, the surface wettability can be changed, known as electrowetting, and the surface charge density can be changed as well [11

• ]. Nanobubbles and boundary slip are believed to have a strong influence on surface wettability and surface charge [12][13][14][15][16][17]. It can be inferred that when a voltage is applied, the surface wettability, surface charge, nanobubbles and boundary slip will be changed, which causes the change in the

Nanoscale particles in technological processes of beneficiation

• Sergey I. Popel,
• Vitaly V. Adushkin and
• Anatoly P. Golub'

Beilstein J. Nanotechnol. 2014, 5, 458–465, doi:10.3762/bjnano.5.53

• vessel walls) result in an appearance of cavitation bubbles of mushroom-like form. The size of the bubbles, the time of their presence on the solid surface, the rate of detachment from the surface, etc. depend on local variations of wettability, roughness of the surface, its bending, and other random

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

• Boris Polyakov,
• Sergei Vlassov,
• Leonid M. Dorogin,
• Jelena Butikova,
• Mikk Antsov,
• Sven Oras,
• Rünno Lõhmus and
• Ilmar Kink

Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13

• deviation from a perfect sphere towards an oblate spheroid according to the wettability of the liquid droplet during solidification. An alternative explanation may be the enlargement of the contact area of Ag NPs due to partial melting or enhanced diffusion of atoms caused by the electron beam (e.g

Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

• Sidney R. Cohen and
• Estelle Kalfon-Cohen

Beilstein J. Nanotechnol. 2013, 4, 815–833, doi:10.3762/bjnano.4.93

• cantilever to the overall mechanical response. Eastman and Zhu show that the adhesion forces depend strongly on the surface energy of the tip, and on the wettability of the tip surface in a humid environment [97]. In ambient conditions, the surface of a polymer is likely to be covered by a thin layer of

Energy-related nanomaterials

• Paul Ziemann and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 678–679, doi:10.3762/bjnano.4.76

• energy savings and a significant decrease of the worldwide CO2 emission [1]. It is noteworthy that the nanopatterning of surfaces and interfaces to reduce friction by tailoring their wettability and anti-fouling behavior is often guided by mimicking nature [2][3]. Contributions of advanced materials

Electrospinning preparation and electrical and biological properties of ferrocene/poly(vinylpyrrolidone) composite nanofibers

• Ji-Hong Chai and
• Qing-Sheng Wu

Beilstein J. Nanotechnol. 2013, 4, 189–197, doi:10.3762/bjnano.4.19

• compatibility, and excellent dissolvability in most organic solvents [16]. In this work, PVP polymer was selected as the carrier for immobilizing ferrocene. By incorporating Fc in PVP, the composite nanofibers would have enhanced wettability due to the presence of PVP. Additionally, the presence of well

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• revealed that the functionalization incorporates chemical species into the VA-CNTs film and modifies the wettability of the sample as well as the CNTs arrangement (according to the gas used in the plasma chamber). Consequently, the value of the coefficient of friction is modified. By contrast, the effect

• pulsed direct-current (DC) plasma can modify radically the wettability of VA-CNTs. The plasma treatment allows the grafting of oxygen-containing groups onto the VA-CNTs tips, altering the polarity of the sample and leading to a more hydrophilic surface. Ramos et al. showed that a CO2 laser irradiation

• post-treatment can reverse the phenomenon. It totally removes the grafted groups and re-establishes the hydrophobic character of the sample. They reported the ability to control the VA-CNTs wettability (from superhydrophilicity to superhydrophobicity) by combining both techniques. The change in the

Controlled positioning of nanoparticles on a micrometer scale

• Fabian Enderle,
• Oliver Dubbers,
• Alfred Plettl and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 773–777, doi:10.3762/bjnano.3.86

• distances of some tens of nanometers creative ideas have been realized based on even three-dimensional DNA spacers linked to Au NPs [23]. Somewhat more flexible with respect to the type of NPs is their positioning, exploiting wettability contrast of a substrate previously prepared by, e.g., microcontact

Forming nanoparticles of water-soluble ionic molecules and embedding them into polymer and glass substrates

• Stella Kiel,
• Olga Grinberg,
• Nina Perkas,
• Jerome Charmet,
• Herbert Kepner and
• Aharon Gedanken

Beilstein J. Nanotechnol. 2012, 3, 267–276, doi:10.3762/bjnano.3.30

• , exploiting the difference in wettability between the regions of the patterned polymeric substrate [3]. Suh et al. [3] fabricated single nanocrystal arrays of various sizes on sub-microwells of poly (ethylene glycol) copolymer, using selective wetting of the hydrophilic regions of the exposed substrate

Surface functionalization of aluminosilicate nanotubes with organic molecules

• Wei Ma,
• Weng On Yah,
• Hideyuki Otsuka and
• Atsushi Takahara

Beilstein J. Nanotechnol. 2012, 3, 82–100, doi:10.3762/bjnano.3.10

• the individual imogolite nanotubes, indicating that these are individual tubes rather than bundles. To the best of our knowledge, this is the first observation of individual imogolite nanotubes with a hydrophobic external surface. The wettability of this dodecylphosphate modified imogolite nanotube

Impact of cell shape in hierarchically structured plant surfaces on the attachment of male Colorado potato beetles (Leptinotarsa decemlineata)

• Bettina Prüm,
• Robin Seidel,
• Holger Florian Bohn and
• Thomas Speck

Beilstein J. Nanotechnol. 2012, 3, 57–64, doi:10.3762/bjnano.3.7

• the hierarchical level of superimposed microstructuring, both wax crystals and cuticular folds have been shown to influence insect attachment strongly [7][8] and also the wettability of the surface [9][10]. Many plant surfaces possess hierarchical structuring but only a few of them have been analysed

• cuticular folds have been shown to minimise wettability [9][10]; conical epidermal cells in petal surfaces have been reported to aid the pollinators’ grip to increase foraging efficiency [6][27] and to have a visual effect [2]. To understand fully the impact of hierarchical surface structuring on the

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• were used to pattern an OTS monolayer on mica sheets, the size of the islands and concentration being affected by the UV flux impinging on the surface, as evidenced by AFM and wettability measurements. The phenomenon of remote degradation raises a question regarding the fidelity of patterns obtained by

Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group

• Einat Tirosh,
• Enrico Benassi,
• Silvio Pipolo,
• Marcel Mayor,
• Michal Valášek,
• Veronica Frydman,
• Stefano Corni and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2011, 2, 834–844, doi:10.3762/bjnano.2.93

• ↔trans switching have been demonstrated for SAMs. These include mechanical testing, as mentioned above, as well as changes in the local surface potential [13][14], UV–vis spectroscopy [10], wettability [15], and direct molecular-resolution imaging by scanning tunneling microscopy [10]. These methods vary

Approaches to nanostructure control and functionalizations of polymer@silica hybrid nanograss generated by biomimetic silica mineralization on a self-assembled polyamine layer

• Jian-Jun Yuan and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2011, 2, 760–773, doi:10.3762/bjnano.2.84

• , nanostructured thin films on substrates with tunable nanostructure and surface morphology are of great importance for various applications, such as photoelectronics [1], high-efficiency sensing and bioanalysis [2][3], protein adsorption [4], cell growth [5], surface wettability control [6] and liquid

• (anatase titania). The silica@titania composite nanosurface exhibited an extreme change in photoresponsive wettability due to the presence of photocatalytic anatase titania, which can decompose hydrophobic organic components bonded to the surface. Results and Discussion The inner wall of a soda-lime glass

• synthesis of functional silica-based nanosurfaces. Silica@titania composite nanograss and photoresponsive surface wettability Finally, we attempted using LPEI in hybrid nanograss as a catalyst for titania deposition, with the aim to synthesize a silica@titania composite nanosurface after high-temperature

Dynamics of capillary infiltration of liquids into a highly aligned multi-walled carbon nanotube film

• Sławomir Boncel,
• Krzysztof Z. Walczak and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2011, 2, 311–317, doi:10.3762/bjnano.2.36

• density of nanotube packing, the thermodynamics of the infiltration process (wettability) were described by the contact angle between the nanotube wall and a liquid meniscus (θ). Once the wettability criterion (θ < 90°) was met, the HACNT film (of free volume equal to 91%) was penetrated gradually by the

• general theory of capillarity can be applied in a prediction of both wettability of HACNT films and the dynamics of capillary rise in the intertube space in various technological applications. Keywords: capillary action; dynamic viscosity; highly aligned carbon nanotubes; superhydrophobicity; wettability

• ; Introduction Wettability of carbon nanotubes (CNTs) and highly aligned carbon nanotube (HACNT) films is an important aspect in numerous technologies including manufacture of composites [1], fabrication of constantly/interchangeably hydrophobic or hydrophilic materials [2][3], nanofluidic devices [4] or sponges

Hierarchically structured superhydrophobic flowers with low hysteresis of the wild pansy (Viola tricolor) – new design principles for biomimetic materials

• Anna J. Schulte,
• Damian M. Droste,
• Kerstin Koch and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 228–236, doi:10.3762/bjnano.2.27

• ). Combinations of relatively thick folds separated by a small distance and thin folds separated by a large distance were found. The width of the folds varied from 260 nm (Violar) to 600 nm (Cosmosr) and the distance between the single folds varied from 210 nm (Dahliar) to 460 nm (Cosmosr). Wettability of the

• petals and their replicas Static CA and the TA measurements were performed to compare the surface structures with the wettability. Two superhydrophobic petals (Rosa CA 155.6° and Viola CA 169°) and two hydrophobic petals (Cosmos CA 118.3° and Dahlia CA 136.4°) were found (Figure 4). The static CA of the

• petals (micropapillae with a folding on top), but a similar wetting behavior as that described for lotus leaves. By an easy and fast replication technique and subsequent hydrophobic coating, biomimetic replicas were fabricated. These replicas possessed the same surface structures and wettability as the

Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

• Philipp Comanns,
• Christian Effertz,
• Florian Hischen,
• Konrad Staudt,
• Wolfgang Böhme and
• Werner Baumgartner

Beilstein J. Nanotechnol. 2011, 2, 204–214, doi:10.3762/bjnano.2.24

• case of Phrynonoma cornutum even directed! – passive transport of water. Results and Discussion Macroscopic morphology and wettability of the lizards' integuments The three species under investigation were chosen because all perform moisture harvesting but developed separately in different arid areas

• the scales, independent of form or species, is the wettability. Application of a water droplet onto the integument leads in all three species to an almost immediate spreading of the water as shown in Figure 3A–C and in the supplementary videos (Supporting Information Files 1–3). In contrast to the

• and any macroscopic geometric parameter of the scales in the three investigated species (data not shown). Thus, either material properties or the micro ornamentation of the scales induce the high wettability. Contact angle and microscopic morphology To quantify the wetting properties we attempted to

Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

• Hans J. Ensikat,
• Petra Ditsche-Kuru,
• Christoph Neinhuis and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 152–161, doi:10.3762/bjnano.2.19

• with contact angles >150° and their surface morphologies. Many studies, in which the properties of lotus leaves were compared with those of other superhydrophobic plants, have shown the superiority of the upper side of the lotus leaf. A standard tool for the determination of wettability or water

• . Only the lotus leaves showed no significant loss of water repellency when water vapour condensed on the surface of the cooled samples at 5 °C. Wagner et al. (2003) [9] examined the morphology of the epidermal structures and the wettability with liquids of varying surface tension such as methanol–water

• mixtures. They reported the lowest wettability by these liquids for the lotus leaves in comparison to other species. They also described the unique shape of the papillae and a very high papillae density (number per area). Chemical analyses [10] and crystal structure analysis by X-ray diffraction [11

Review of "Contact Mechanics and Friction: Physical Principles and Applications" by Valentin L. Popov

• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2011, 2, 57–58, doi:10.3762/bjnano.2.7

• contact problem in biology see [4]). Biological and technical systems have many common features. First, the mechanical interaction occurs on identical length and force scales [5]. In both types of systems, surface properties – for example wettability, microstructure or surface chemistry – have a strong