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

• for unprotected SWCNTs (381 n-type CNFETs) to 134 kΩ for protected SWCNTs (110 n-type CNFETs) (Figure 8d) [71]. The median value of the hysteresis width also narrowed from 2.2 V to 0.5 V (Figure 8e) [71]. In addition, the widths (see the insets in Figure 8d,e) of the dispersions of on-resistance and

Effect of silver nanoparticles on human mesenchymal stem cell differentiation

• Christina Sengstock,
• Jörg Diendorf,
• Matthias Epple,
• Thomas A. Schildhauer and
• Manfred Köller

Beilstein J. Nanotechnol. 2014, 5, 2058–2069, doi:10.3762/bjnano.5.214

• predict the possible health risks. Experimental Synthesis of silver nanoparticles Polyvinylpyrrolidone (PVP)-coated silver nanoparticles were synthesized by reduction with glucose in the presence of PVP as described previously [19][21]. The final silver concentration in all dispersions was determined by

Rapid degradation of zinc oxide nanoparticles by phosphate ions

• Rudolf Herrmann,
• F. Javier García-García and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2007–2015, doi:10.3762/bjnano.5.209

• dispersions are due to Zn2+ ions whose concentration is almost equal in any sample within three days at pH 7.6 [11]. However, another investigation showed a higher toxicity for smaller particles [12]. In addition, the toxicity to marine organism was found to be shape-dependent [13]. Toxicity seems to parallel

• course of the reaction of buffer B with the nanoparticles for one hour, the ζ-potential of all particle dispersions has a tendency to shift to more negative values, and the hydrodynamic diameter decreases (Table 2). Due to the highly irregular shape of the zinc phosphate particles and their varying

• [26]. The successful fluorescence labelling of ZnO-NP was checked by irradiating the dispersions at 254 nm. Dry solvents (stored over molecular sieves 4 Å) were used in all cases. Solvents and reagents were purchased from Merck unless otherwise noted. TEM pictures were taken with a JEM 2100 F

Photodetectors based on carbon nanotubes deposited by using a spray technique on semi-insulating gallium arsenide

• Domenico Melisi,
• Maria Angela Nitti,
• Marco Valentini,
• Antonio Valentini,
• Teresa Ligonzo,
• Giuseppe De Pascali and
• Marianna Ambrico

Beilstein J. Nanotechnol. 2014, 5, 1999–2006, doi:10.3762/bjnano.5.208

• THOR Labs photodiode (Thorlabs PM100D with a silicon photodiode S120VC) was used to normalize the sample photocurrent to the incident light intensity for all the measurements in the vis–NIR region. Results and Discussion TEM images acquired at 120 kV of the spray dispersions obtained with both the

Carbon nano-onions (multi-layer fullerenes): chemistry and applications

• Juergen Bartelmess and
• Silvia Giordani

Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207

• phenylated CNOs were not soluble in organic solvents, but sulfonation with oleum, followed by treatment with aqueous NaOH lead to a highly soluble product, which formed stable dispersions in water as well as in ethanol (Scheme 4B). The last reaction investigated was based on an earlier reported oxidation of

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

• Sebastian Ahlberg,
• Alexandra Antonopulos,
• Jörg Diendorf,
• Ralf Dringen,
• Matthias Epple,
• Rebekka Flöck,
• Wolfgang Goedecke,
• Christina Graf,
• Nadine Haberl,
• Jens Helmlinger,
• Fabian Herzog,
• Frederike Heuer,
• Stephanie Hirn,
• Christian Johannes,
• Stefanie Kittler,
• Manfred Köller,
• Katrin Korn,
• Wolfgang G. Kreyling,
• Fritz Krombach,
• Jürgen Lademann,
• Kateryna Loza,
• Eva M. Luther,
• Marcelina Malissek,
• Martina C. Meinke,
• Daniel Nordmeyer,
• Anne Pailliart,
• Jörg Raabe,
• Fiorenza Rancan,
• Barbara Rothen-Rutishauser,
• Eckart Rühl,
• Carsten Schleh,
• Andreas Seibel,
• Christina Sengstock,
• Lennart Treuel,
• Annika Vogt,
• Katrin Weber and
• Reinhard Zellner

Beilstein J. Nanotechnol. 2014, 5, 1944–1965, doi:10.3762/bjnano.5.205

• silver nanoparticles were chemically characterized, purified from synthesis by-products and the silver content in the dispersions was measured for each batch. Unless otherwise noted, in all cases in which silver nanoparticles are referred to in the following sections, they are PVP-coated with a negative

• have investigated whether STXM can be applied to investigate the cellular uptake process of silver nanoparticles in human mesenchymal stem cells (hMSC). For this purpose, hMSC were grown on collagen-coated Si3N4-membranes and incubated for 24 h with O2-free aqueous dispersions of silver particles (c

• efficiently accumulate silver nanoparticles in a process that increases their silver content proportional to the concentration of particles applied at least for incubations with silver nanoparticle dispersions containing silver concentrations of up to 300 µM (32.4 µg mL−1) [108]. After 4 h of incubation with

The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions

• Christoph Bantz,
• Olga Koshkina,
• Thomas Lang,
• Hans-Joachim Galla,
• C. James Kirkpatrick,
• Roland H. Stauber and
• Michael Maskos

Beilstein J. Nanotechnol. 2014, 5, 1774–1786, doi:10.3762/bjnano.5.188

• ], which orders ions according to the magnitude of their destabilizing effect on colloidal dispersions. Nevertheless, small amounts of salt should be added to the eluate in AF-FFF to minimize electrostatic repulsion [43]. For application in the fields of the bio-nano sciences, physiological salt contents

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• ways through chemical adsorption of ordered architectures [33][34] and preserve the extended networks of the CNTs seems therefore very attractive. In this review, starting from several examples of good dispersions and dispersants, we intend to systematically identify the features that allow a molecule

• provided by magnetic stirring, reflux, shear mixing, or, most commonly, ultrasonication either mild sonication in a bath or high-power sonication using a tip [16]. Once exfoliated, the simplest stable CNTs dispersions have been achieved by using solvent molecules able to efficiently interact with CNTs such

• mixing a negative value. However, NMP molecules could be removed by heating to 340 °C, leaving perfectly intact nanotubes and demonstrating that NMP was physisorbed via van der Waals interactions onto the nanotube surface. Good and relatively stable dispersions have been obtained also by sonicating CNTs

Protein-coated pH-responsive gold nanoparticles: Microwave-assisted synthesis and surface charge-dependent anticancer activity

• Dickson Joseph,
• Nisha Tyagi,
• Christian Geckeler and
• Kurt E.Geckeler

Beilstein J. Nanotechnol. 2014, 5, 1452–1462, doi:10.3762/bjnano.5.158

• (Figure S1, Supporting Information File 1). Photographs of the dispersions (Figure S2, Supporting Information File 1) were taken after the microwave irradiation under different pH conditions, and the color characteristic of the AuNPs was observed only for reactions carried out at the intrinsic pH values

• . Whereas at acidic, neutral and basic pH conditions, different colored dispersions were observed, and detailed studies on their size and shape are in progress. Hence, varying the pH of the protein solution modifies the structural confirmation of the protein, which alters the native state of the amino acids

• IEPs of the protein-coated AuNPs, their aqueous dispersions were subjected to pH-dependent zeta potential titration studies. The AuNPs behavior in the human body can be understood by examining the correlation between pH and zeta potential. Figure 3 shows the results for the different protein-coated

The protein corona protects against size- and dose-dependent toxicity of amorphous silica nanoparticles

• Dominic Docter,
• Christoph Bantz,
• Dana Westmeier,
• Hajo J. Galla,
• Qiangbin Wang,
• James C. Kirkpatrick,
• Peter Nielsen,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2014, 5, 1380–1392, doi:10.3762/bjnano.5.151

• methods. First, the size, spherical shape and homogeneity of the ASP were visualized by transmission electron microscopy (TEM) (Figure 1). Next, we examined the stability of the ASP dispersions in water, salt-containing buffer (buffer A), and cell culture medium (DMEM) with or without the addition of 10

• to link individual or multiple particle parameters, such as geometry, pore size or surface functionalization to the observed nanobiological effects. The negative zeta potential, hydrodynamic diameter and colloidal stability of the ASP dispersions were obtained in water, salt-containing buffer, and

• dispersions of ASP were purchased from Nyacol Nano Technologies (ASP20, ASP30, ASP100), Sigma (Sigma-Aldrich, Taufkirchen, Germany) (ASP30L) or Kisker Products (ASP30F, ASP30F-COOH) and used as received. The ASP were characterized with respect to shape, size, and size distribution in the dry state as well as

Mimicking exposures to acute and lifetime concentrations of inhaled silver nanoparticles by two different in vitro approaches

• Fabian Herzog,
• Kateryna Loza,
• Sandor Balog,
• Martin J. D. Clift,
• Matthias Epple,
• Peter Gehr,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2014, 5, 1357–1370, doi:10.3762/bjnano.5.149

• vary from incorporations into materials such as for textile fabrics, medical devices, air filters, and food containers, to dispersions, e.g., for water disinfectants and cosmetics (e.g., deodorants), as well as many more commodities for ‘everyday use’ [7][8]. The application of Ag NPs leading to their

• kDa MWCO centrifugal filter units (Vivaspin 20; Sartorius Stedim AG, Tagelswangen, Switzerland) at 3000g by diafiltration for 10 min. The Ag NP dispersions were always freshly prepared before each individual experiment. Nanoparticle characterisation The size distribution and zeta potential of the Ag

PEGylated versus non-PEGylated magnetic nanoparticles as camptothecin delivery system

• Paula M. Castillo,
• Mario de la Mata,
• Maria F. Casula,
• José A. Sánchez-Alcázar and
• Ana P. Zaderenko

Beilstein J. Nanotechnol. 2014, 5, 1312–1319, doi:10.3762/bjnano.5.144

• -PEG[CPT]. Stock dispersions of USM[CPT] and USM-PEG[CPT] were prepared in PBS (pH 7.5) with a CPT concentration of 5 mM, and 1 µL of this dispersion was added to H460 cells previously cultured (confluent; 1mL final volume, 5 μM final CPT concentration). Cells with nanoparticles and references were

Model systems for studying cell adhesion and biomimetic actin networks

• Dorothea Brüggemann,
• Johannes P. Frohnmayer and
• Joachim P. Spatz

Beilstein J. Nanotechnol. 2014, 5, 1193–1202, doi:10.3762/bjnano.5.131

• Heise et al. in 1991. Talin was purified from blood platelets and incorporated into vesicles by cyclic freeze-thawing of co-dispersions containing vesicles and talin. This technique yielded a uniform orientation of platelet talin with its large head group pointing to the outer vesicle side [74]. The

Optical and structural characterization of oleic acid-stabilized CdTe nanocrystals for solution thin film processing

• Claudio Davet Gutiérrez-Lazos,
• Mauricio Ortega-López,
• Manuel A. Pérez-Guzmán,
• A. Mauricio Espinoza-Rivas,
• Francisco Solís-Pomar,
• Rebeca Ortega-Amaya,
• L. Gerardo Silva-Vidaurri,
• Virginia C. Castro-Peña and
• Eduardo Pérez-Tijerina

Beilstein J. Nanotechnol. 2014, 5, 881–886, doi:10.3762/bjnano.5.100

• for preserve their size effects [20][21][22]. All of these techniques need ink-like stable dispersions comprising functionalized nanomaterials dispersed in a convenient solvent. Drop-casting offers a cost efficient production of photovoltaic semiconductor thin films. Nevertheless, depending on the

Pyrite nanoparticles as a Fenton-like reagent for in situ remediation of organic pollutants

• Carolina Gil-Lozano,
• Elisabeth Losa-Adams,
• Alfonso F.-Dávila and
• Luis Gago-Duport

Beilstein J. Nanotechnol. 2014, 5, 855–864, doi:10.3762/bjnano.5.97

• of H2O2 generated and on the dye decoloration (degradation) pathway, we performed kinetic experiments with dispersions of pyrite nanoparticles or microparticles (Figure 3, see section Experimental below). The same initial particle loading (0.08 g/L) and dye concentration (0.1 mg/L) were used. When

Injection of ligand-free gold and silver nanoparticles into murine embryos does not impact pre-implantation development

• Ulrike Taylor,
• Wiebke Garrels,
• Annette Barchanski,
• Svea Peterson,
• Laszlo Sajti,
• Andrea Lucas-Hahn,
• Lisa Gamrad,
• Ulrich Baulain,
• Sabine Klein,
• Wilfried A. Kues,
• Stephan Barcikowski and
• Detlef Rath

Beilstein J. Nanotechnol. 2014, 5, 677–688, doi:10.3762/bjnano.5.80

• the embryo-toxicity of silver nanoparticles. All trials exploring the subject in piscine embryos and the study performed on mice used particles derived by chemical means. Despite post-production purification steps, such particle dispersions contain remnants of stabilizing and reducing agents, which

Chemi- vs physisorption in the radical functionalization of single-walled carbon nanotubes under microwaves

• Victor Mamane,
• Guillaume Mercier,
• Junidah Abdul Shukor,
• Jérôme Gleize,
• Aziz Azizan,
• Yves Fort and
• Brigitte Vigolo

Beilstein J. Nanotechnol. 2014, 5, 537–545, doi:10.3762/bjnano.5.63

• dispersions of the f-SWNTs in tetrahydrofuran (THF). The SWNTs functionalized under 5 min or 10 min of microwaves could be well dispersed leading to dark solutions. As the functionalization duration was increased to 15 min, f-SWNT-15min was very poorly dispersed as a consequence of a rapid aggregation and

Template based precursor route for the synthesis of CuInSe₂ nanorod arrays for potential solar cell applications

• Mikhail Pashchanka,
• Jonas Bang,
• Niklas S. A. Gora,
• Ildiko Balog,
• Rudolf C. Hoffmann and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2013, 4, 868–874, doi:10.3762/bjnano.4.98

• arrays. Another possibility could be a direct deposition of the as-prepared CuInSe2 nanorods from dispersions in organic solvents directly onto the appropriate substrate. Both routes are currently studied in our laboratories. SEM micrographs of CuInSe2 nanorod arrays after the final conversion step at

Near-field effects and energy transfer in hybrid metal-oxide nanostructures

• Ulrich Herr,
• Balati Kuerbanjiang,
• Cahit Benel,
• Giorgos Papageorgiou,
• Manuel Goncalves,
• Johannes Boneberg,
• Paul Leiderer,
• Paul Ziemann,
• Peter Marek and
• Horst Hahn

Beilstein J. Nanotechnol. 2013, 4, 306–317, doi:10.3762/bjnano.4.34

• adjusted over a wide range by the choice of the sphere size. In our study, we have used polystyrene spheres with diameters of 1 μm or 3 μm. The water-based dispersions were dried under constant temperature and air flow to assure a constant evaporation rate of the solvent. In the next step, we deposited Ag

• enhancement will require further optimization of the nanoparticle arrangement. E. Study of quenching effects using organic pigments The results reported up to know show the importance of obtaining a narrow distribution of nanoparticle sizes. This can be achieved by stabilizing the nanoparticle dispersions

Influence of the diameter of single-walled carbon nanotube bundles on the optoelectronic performance of dry-deposited thin films

• Kimmo Mustonen,
• Toma Susi,
• Antti Kaskela,
• Patrik Laiho,
• Ying Tian,
• Albert G. Nasibulin and
• Esko I. Kauppinen

Beilstein J. Nanotechnol. 2012, 3, 692–702, doi:10.3762/bjnano.3.79

• sonication (cutting), acid cleaning (unintentional doping) or surfactant-based dispersions (residual surface contamination) [13][14]. Characteristic features have been explored previously by geometric scaling arguments and by comparing the performance of SWCNT films fabricated by different synthesis and

Conducting composite materials from the biopolymer kappa-carrageenan and carbon nanotubes

• Ali Aldalbahi,
• Jin Chu,
• Peter Feng and
• Marc in het Panhuis

Beilstein J. Nanotechnol. 2012, 3, 415–427, doi:10.3762/bjnano.3.48

• [8][25][26][27][28][29]. For example, gellan gum-CNT dispersions have been wet-processed by inkjet printing into optically transparent films, which displayed sensitivity to water vapour [30]. Other commonly employed wet-processing methods used to process biopolymer–CNT dispersions into materials

• these CNT networks are contingent on the CNT/dispersant ratio. Increasing the nanotube concentration usually leads to an increase in the electrical conductivity and to mechanical reinforcement [31][32]. Vacuum filtration of dispersions usually results in films, which are generally referred to as

• over time. The absorbance at an arbitrarily picked wavelength (660 nm) becomes independent of sonication after 20 and 35 min of sonication for MWNTs and SWNTs, respectively (Figure 3c). Optical microscopy revealed the presence of aggregates in the dispersions subjected to short sonication times (5 min

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

• organic solvent, but after modification with BMPOPO4, the resulting modified imogolite can be dispersed in various solvents. Unfortunately, the dispersions are neither homogenous nor stable. However, when PMMA was grafted to the surface of imogolite nanotubes, PMMA-g-imogolite showed good dispersibility

Improvement of the oxidation stability of cobalt nanoparticles

• Celin Dobbrow and
• Annette M. Schmidt

Beilstein J. Nanotechnol. 2012, 3, 75–81, doi:10.3762/bjnano.3.9

• oxidation of particle dispersions and powders was kinetically investigated and compared to as-prepared particle preparations. A post-synthesis treatment with different alcohols was employed, and we also investigate the influence of two different polymer shells on the oxidation process. We found a parabolic

• -controlled magnetic particle dispersions with strong magnetic properties and a good stability against oxygen and water. With a high saturation magnetization and strong magnetic anisotropy, cobalt nanoparticles in a size range between 10 and 40 nm behave as ferromagnetically blocked, single-domain magnetic

• to 20 days from synthesis, and were immediately investigated with respect to their magnetic properties by vibrating sample magnetometry (VSM). In addition to the dispersions, the dried powders of selected preparations were investigated. The magnetization curves of all toluene-based particle charges

Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

• Lars Borchardt,
• Martin Oschatz,
• Robert Frind,
• Emanuel Kockrick,
• Martin R. Lohe,
• Christoph P. Hauser,
• Clemens K. Weiss,
• Katharina Landfester,
• Bernd Büchner and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 638–644, doi:10.3762/bjnano.2.67

• holey carbon and dried using an infrared lamp. The TEM investigations were carried out on a Cs-corrected JEOL JEM-2010F. Particle sizes were determined with photon cross-correlation spectroscopy (PCCS) using a Nanophox particle sizer (Sympatec GmbH). The dispersions were diluted with demineralized water

Platinum nanoparticles from size adjusted functional colloidal particles generated by a seeded emulsion polymerization process

• Nicolas Vogel,
• Ulrich Ziener,
• Achim Manzke,
• Alfred Plettl,
• Paul Ziemann,
• Johannes Biskupek,
• Clemens K. Weiss and
• Katharina Landfester

Beilstein J. Nanotechnol. 2011, 2, 459–472, doi:10.3762/bjnano.2.50

• -fold increase in volume. Larger diameters of seeded colloids could not be achieved as the present reaction pathway appears to break down with higher monomer excesses: Secondary nucleation or instable dispersions are the result. As all reactions produced an increase of particle size, it can be stated

• concentrations were below the critical value for micelle formation (cmc). Such concentrations are used in conventional emulsion polymerization and lead to particles nucleated in monomer swollen micelles [13]. Figure 3b and c show representative SEM micrographs of the resulting dispersions. For both cases

• . Additionally, both diffusion and solubility of the monomer are affected drastically by compositional changes in the continuous phase. In order to investigate these effects, systematic variations of the continuous phase were performed. Figure 4 and Table 4 show the properties of the resulting dispersions and