Dynamic behavior of a nematic liquid crystal mixed with CoFe₂O₄ ferromagnetic nanoparticles in a magnetic field

• Emil Petrescu,
• Cristina Cirtoaje and
• Cristina Stan

Beilstein J. Nanotechnol. 2017, 8, 2467–2473, doi:10.3762/bjnano.8.246

• Dynamic measurements were performed with a reference sample cell filled only with 5CB and a cell filled with a mixture of 5CB and 1% (volumetric ratio) of CoFe2O4 nanoparticles. These nanoparticles are nano-sized ferrite platelets (30 nm diameter) obtained using a co-precipitation method with iron

Involvement of two uptake mechanisms of gold and iron oxide nanoparticles in a co-exposure scenario using mouse macrophages

• Dimitri Vanhecke,
• Dagmar A. Kuhn,
• Dorleta Jimenez de Aberasturi,
• Sandor Balog,
• Ana Milosevic,
• Dominic Urban,
• Diana Peckys,
• Niels de Jonge,
• Wolfgang J. Parak,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2017, 8, 2396–2409, doi:10.3762/bjnano.8.239

• gold (AuNPs) and iron oxide nanoparticles (FeOxNPs) either alone or combined. Environmental scanning electron microscopy revealed that single NPs of both types bound within minutes on the cell surface but with a distinctive difference between FeOxNPs and AuNPs. Uptake analysis studies based on laser

• investigated the biological effects of a combined exposure. One example was the co-exposure of epithelial A549 lung cells in cultures to carbon black and iron oxide NPs. It was reported that exposing cells simultaneously to these NPs caused a synergistic oxidative effect, which was significantly greater than

• in a complex colloidal system, such as the vascular system. The aim of this work was to study the combined effect of two model NPs on cellular uptake, that is gold (AuNPs) and iron oxide NPs (FeOxNPs) stabilized with the same polymer shell and incorporated fluorophores. The NPs can be distinguished

Suppression of low-energy dissociative electron attachment in Fe(CO)₅ upon clustering

• Jozef Lengyel,
• Peter Papp,
• Štefan Matejčík,
• Jaroslav Kočišek,
• Michal Fárník and
• Juraj Fedor

Beilstein J. Nanotechnol. 2017, 8, 2200–2207, doi:10.3762/bjnano.8.219

• the most attention in recent years (i.e., dissociative electron attachment at energies close to 0 eV) becomes suppressed upon increasing aggregation of iron pentacarbonyl. We attribute this suppression to the electrostatic shielding of a long-range interaction that strongly enhances the dissociative

• electron attachment in isolated Fe(CO)5. Keywords: aggregation effects; dissociative electron attachment; FEBID; iron pentacarbonyl; long-range interactions; Introduction In recent years a number of gas-phase studies on molecules that are commonly used as precursors in electron-induced nanofabrication

• have stressed the importance of electrons with energy below 1 eV [1][2][3]. In many cases, these cause the cleavage of one metal–ligand bond via dissociative electron attachment (DEA) and corresponding cross sections reach unusually high values [2][3]. Iron pentacarbonyl, Fe(CO)5, is no exception: the

Evaluating the toxicity of TiO₂-based nanoparticles to Chinese hamster ovary cells and Escherichia coli: a complementary experimental and computational approach

• Alicja Mikolajczyk,
• Natalia Sizochenko,
• Ewa Mulkiewicz,
• Anna Malankowska,
• Michal Nischk,
• Przemyslaw Jurczak,
• Seishiro Hirano,
• Grzegorz Nowaczyk,
• Adriana Zaleska-Medynska,
• Jerzy Leszczynski,
• Agnieszka Gajewicz and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2017, 8, 2171–2180, doi:10.3762/bjnano.8.216

• bactericidal activity (towards Gram-positive B. subtilis and Gram-negative P. putida) than NPs activated by UV [4]. At the same time, no significant cytotoxicity has been detected for TiO2 doped with nitrogen (N), gold (Au) or selenium (Sn) [20][21]. Whereas, copper oxide-doped TiO2 and iron/nitrogen co-doped

• increasing concentration of Bi2WO6 [23]. In another contribution, the photo-oxidation capability of iron-doped TiO2 NPs increased during exposure to near-visible light. Fe-doped TiO2 NPs inhibited the macrophage RAW 264.7 [24]. Hence the same unique properties of surface-modified TiO2-based nanomaterials

Systematic control of α-Fe₂O₃ crystal growth direction for improved electrochemical performance of lithium-ion battery anodes

• Nan Shen,
• Miriam Keppeler,
• Barbara Stiaszny,
• Holger Hain,
• Filippo Maglia and
• Madhavi Srinivasan

Beilstein J. Nanotechnol. 2017, 8, 2032–2044, doi:10.3762/bjnano.8.204

• chelate complexes with ferric ions in solution, leading to a directional dependency of OH− attacks for subsequent hydrolysis processes, which results in a targeted growth direction of iron oxide products [29]. Furthermore, diamines directly coordinate to ferric lattice species and the complexes are

• -colored product was obtained. For a systematic study, the concentration of FeCl3·6H2O was varied, while the ratio between iron ions and organic SCA was kept constant. The effectiveness of the SCA was compared by using ethylenediamine (99%, Sigma-Aldrich), 2,3-diaminobutane (95%, Otava) and N

• samples was analyzed using a JEOL 6340F field emission scanning electron microscope (FESEM) in secondary electron imaging mode. The accelerating voltage was set to 5 kV. The electrodes were prepared by mixing 40% of as-synthesized active iron oxide powder with 40% of conductive additives (Super P Li

A systematic study of the controlled generation of crystalline iron oxide nanoparticles on graphene using a chemical etching process

• Peter Krauß,
• Jörg Engstler and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2017, 8, 2017–2025, doi:10.3762/bjnano.8.202

• without the need for any additional post-processing. During the course of our transfer studies, we found that the etching process that is usually employed can lead to contamination of the graphene layer with the Faradaic etchant component FeCl3, resulting in the deposition of iron oxide FexOy

• nanoparticles on the graphene surface. We systematically analyzed the removal of the copper substrate layer and verified that crystalline iron oxide nanoparticles could be generated in controllable density on the graphene surface when this process is optimized. It was further confirmed that the FexOy particles

• on graphene are active in the catalytic growth of carbon nanotubes when employing a water-assisted CVD process. Keywords: carbon nanotubes; chemical vapor deposition; graphene; iron oxide; nanoparticles; Introduction Graphene was first described by Boehm and coworkers in the early 1960s [1][2][3][4

Synthesis and functionalization of NaGdF₄:Yb,Er@NaGdF₄ core–shell nanoparticles for possible application as multimodal contrast agents

• Dovile Baziulyte-Paulaviciene,
• Vitalijus Karabanovas,
• Marius Stasys,
• Greta Jarockyte,
• Vilius Poderys,
• Simas Sakirzanovas and
• Ricardas Rotomskis

Beilstein J. Nanotechnol. 2017, 8, 1815–1824, doi:10.3762/bjnano.8.183

• that the nonionic surfactant Tween 80 helps different nanoparticles (gold, silver and iron oxide) to become well-dispersed in aqueous solution even in the presence of biological molecules, such as different serum proteins [19][20][21]. However, information about Tween 80-coated gadolinium-based UCNPs

Methionine-mediated synthesis of magnetic nanoparticles and functionalization with gold quantum dots for theranostic applications

• Arūnas Jagminas,
• Agnė Mikalauskaitė,
• Vitalijus Karabanovas and
• Jūrate Vaičiūnienė

Beilstein J. Nanotechnol. 2017, 8, 1734–1741, doi:10.3762/bjnano.8.174

• Biocompatible superparamagnetic iron oxide nanoparticles (NPs) through smart chemical functionalization of their surface with fluorescent species, therapeutic proteins, antibiotics, and aptamers offer remarkable potential for diagnosis and therapy of disease sites at their initial stage of growth. Such NPs can

• nanomedicine, biocompatible iron oxide-based NPs have attracted particular interest due to their size-dependent magnetic, optical and chemical properties that allow for the design of NPs for multimodal imaging and photothermal therapy of cancer cells [1]. Dual-imaging probes, capable to perform simultaneously

• magnetic NPs through biocompatible links such as Au–S– [7]. Iron oxide NPs can be coated with polymeric or silica shells containing incorporated gold NPs [8][9][10]. However, in this case the size of the magnetic NPs increases up to ten times [9], resulting in a significant decrease in the saturation

Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces

• Florian Rückerl,
• Daniel Waas,
• Bernd Büchner,
• Martin Knupfer,
• Dietrich R. T. Zahn,
• Francisc Haidu,
• Torsten Hahn and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 1601–1615, doi:10.3762/bjnano.8.160

• ][8]. Phthalocyanine molecules can harbor a number of metal ions, in particular transition-metal ions such as cobalt, iron or manganese. A special characteristic of transition-metal centered phthalocyanines is, that transition-metal ions often are characterized by a magnetic moment, and therefore such

Formation of ferromagnetic molecular thin films from blends by annealing

• Peter Robaschik,
• Ye Ma,
• Salahud Din and
• Sandrine Heutz

Beilstein J. Nanotechnol. 2017, 8, 1469–1475, doi:10.3762/bjnano.8.146

• already allows the molecules to rearrange into large elongated crystallites. This was observed previously for iron phthalocyanine (FePc) thin films deposited at different substrate temperatures [16]. However, in that case the length of the major axis was found to be 200 nm at a temperature of 260 °C. The

Cationic PEGylated polycaprolactone nanoparticles carrying post-operation docetaxel for glioma treatment

• Cem Varan and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1446–1456, doi:10.3762/bjnano.8.144

• -time and also enhanced the concentration of BCNU in the brain tumor area [27]. In addition to drug delivery, core–shell nanoparticles such as magnetic nanoparticles [28], quantum dots [29], nanodiamonds [30], nanocrystals [31] and iron oxide nanoparticles [32] are studied as imaging and detection

Micro- and nano-surface structures based on vapor-deposited polymers

• Hsien-Yeh Chen

Beilstein J. Nanotechnol. 2017, 8, 1366–1374, doi:10.3762/bjnano.8.138

• of two types of poly-p-xylylenes, which are commercially named parylene™ N and parylene™ C, respectively) were found to deactivate on several high-energy surfaces of several transition metals such as iron, copper, silver, platinum, and the salts of these metals. The monomer deactivation inhibits the

• discovery, applications have been demonstrated to generate Nomarski poly(p-phenylene vinylene) (PPV) patterns from selectively deposited parylene™ N on surfaces with photolithographically fabricated iron structures (inhibitors) [78]. A required pore-sealing process for porous dielectrics was also performed

Synthesis of [Fe(L_eq)(L_ax)]_n coordination polymer nanoparticles using blockcopolymer micelles

• Christoph Göbel,
• Ottokar Klimm,
• Florian Puchtler,
• Sabine Rosenfeldt,
• Stephan Förster and
• Birgit Weber

Beilstein J. Nanotechnol. 2017, 8, 1318–1327, doi:10.3762/bjnano.8.133

• concentration of [Fe(Leq)(Lax)]n. The core of the nanoparticles is about 45 nm in diameter due to the templating effect of the BCP micelle, independent of the used iron complex and [Fe(Leq)(Lax)]n concentration. The spin-crossover properties of the composite material are similar to those of the bulk for FeLeq

• were already synthesised in methanol [44][50], the coordination polymer [FeLeq(bpey)]n is described here for the first time. The coordination polymers 1, 2 and 3 were synthesised by dissolving the iron(II) complex [FeLeq(MeOH)2] and the respective axial ligand in THF. The solution was refluxed for 1 h

• the χMT product (χM = magnetic susceptibility, T = temperature) as a function of the temperature is given. Sample 1 is paramagnetic at RT with a χMT value of 3.25 cm3·K·mol−1, typical for iron(II) in the HS state [51]. Upon cooling the χMT value remains constant down to 140 K where an abrupt

Nanotopographical control of surfaces using chemical vapor deposition processes

• Meike Koenig and
• Joerg Lahann

Beilstein J. Nanotechnol. 2017, 8, 1250–1256, doi:10.3762/bjnano.8.126

• ]. Due to secondary adsorption on deactivated monomers, the authors found a maximum thickness of selectively grown polymer depending on the metal and the monomer type. Iron was found to be the most efficient inhibitor for the investigated polymers. By patterning iron molecules via photolithography or

• carboxylic acid-terminated alkanethiols, iron salt exposure on the surface could be spatially defined, which again prevented polymer growth [18]. Further investigations with a wider variety of PPX derivatives were conducted by Chen et al. [22]. For PPX derivatives containing oxygen or nitrogen, no inhibition

Growth, structure and stability of sputter-deposited MoS₂ thin films

• Reinhard Kaindl,
• Bernhard C. Bayer,
• Roland Resel,
• Thomas Müller,
• Viera Skakalova,
• Gerlinde Habler,
• Rainer Abart,
• Alexey S. Cherevan,
• Dominik Eder,
• Maxime Blatter,
• Fabian Fischer,
• Jannik C. Meyer,
• Dmitry K. Polyushkin and
• Wolfgang Waldhauser

Beilstein J. Nanotechnol. 2017, 8, 1115–1126, doi:10.3762/bjnano.8.113

• was previously reported [29][49]. Given that the films presented in this study have been sputtered from a MoS2 target with a purity of 99.5 wt %, which contains 0.03 wt % SiO2, 0.02 wt % MoO3, 0.01 wt % copper oxide (CuO), 0.019 wt % iron (Fe) and up to 0.20 wt % not specified compounds, in a metallic

High photocatalytic activity of Fe₂O₃/TiO₂ nanocomposites prepared by photodeposition for degradation of 2,4-dichlorophenoxyacetic acid

• Shu Chin Lee,
• Hendrik O. Lintang and
• Leny Yuliati

Beilstein J. Nanotechnol. 2017, 8, 915–926, doi:10.3762/bjnano.8.93

• of the best modifiers, the use of a co-catalyst has been recognized to improve the photocatalytic performance of semiconductor photocatalysts as it promotes charge separation and suppresses photocorrosion of the semiconductor photocatalyst [3][4]. One of the potential co-catalyst modifiers is iron

• /TiO2 catalysts without heat treatment at ambient conditions. Using iron(III) nitrate nonahydrate as the precursor, active and stable Fe2O3/TiO2 was successfully prepared via photodeposition [15]. However, the actual amount of iron precursor in the prepared Fe2O3/TiO2 was much lower than that added. In

• the present study, Fe2O3/TiO2 nanocomposites were prepared by a similar approach but using iron(III) acetylacetonate as the precursor to facilitate a complete photodeposition process. The properties and activity results were compared with those prepared by the commonly used impregnation approach

Investigation of growth dynamics of carbon nanotubes

• Marianna V. Kharlamova

Beilstein J. Nanotechnol. 2017, 8, 826–856, doi:10.3762/bjnano.8.85

• metal, ΔHfusion is the latent heat of fusion, ρs and ρl are the densities of solid and liquid metal, respectively, σsl is the solid–liquid interfacial energy and σl is the surface energy of the liquid [50][51]. Figure 2 demonstrates the melting temperature of iron, nickel, gold and silver particles as a

• diameter of 1–3 nm should be in a liquid form at typical synthesis conditions of nanotubes. Secondly, the melting point of catalytic particles is decreased by forming a eutectic with carbon [52]. In [52], it was calculated that melting points of iron particles with diameters of 1–2 nm, which catalyze the

• synthesis [69]. In [66][67], XRD studies revealed the formation of iron oxides and carbide before the nanotube growth. Iron carbide was observed immediately before the start of the growth [67], and the process of its decomposition to Fe and graphite coincided with the onset of the nanotube growth [66]. In

Selective detection of Mg²⁺ ions via enhanced fluorescence emission using Au–DNA nanocomposites

• Tanushree Basu,
• Khyati Rana,
• Niranjan Das and
• Bonamali Pal

Beilstein J. Nanotechnol. 2017, 8, 762–771, doi:10.3762/bjnano.8.79

• detect the presence of metal ions in a solution. Calcium (Ca), iron (Fe) and magnesium (Mg) were chosen because of their high abundance and importance in nature. Au–DNA NCs are a convenient and time-effective approach to metal detection. As can be observed in Figure 9a, the detection of Ca2+ did not

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• scalable and relatively cost effective [14][15][16]. In particular, among all the TMO NPs, titanium dioxide [17], manganese oxide [18], iron oxide [19] and zinc oxide [20] have attracted the most attention due to their particular interesting and advantageous properties. By changing the reaction conditions

• the conducting network [121]. Iron oxide (Fe2O3)–graphene hybrids Fe2O3 has the advantages that it can be produced in high abundance, with low cost, and the nontoxicity of Fe results in a reduced environmental concern. Therefore, it is expected to meet the requirements of future energy storage systems

• porous iron oxide ribbons by controlling the nucleation and growth of iron precursors on a graphene surface, which was followed by an annealing treatment and used for high-performance lithium storage [157]. Liang et al. have prepared graphene–Fe3O4 NP hybrid paper by a filtration process which shows an

Carbon nanotube-wrapped Fe₂O₃ anode with improved performance for lithium-ion batteries

• Guoliang Gao,
• Yan Jin,
• Qun Zeng,
• Deyu Wang and
• Cai Shen

Beilstein J. Nanotechnol. 2017, 8, 649–656, doi:10.3762/bjnano.8.69

• Synthesis of metal hydroxide composite The composite was synthesized via a simple hydrothermal method. Firstly, iron(III) chloride hexahydrate (FeCl3·6H2O, 2.1624 g, ≥99.0%, Sinopharm Chemical Reagent Co, Ltd) and ethanolamine were each dissolved separately 100 mL distilled water and stirred for 30 min to

• obtain uniform solutions. Following that, the iron(III) chloride solution was added dropwise into the ethanolamine solution. The solution was then kept at room temperature for three days to obtain orange metal hydroxide solution. Synthesis of Fe2O3-CMWCNT composites Approximately 50 mL of the

• good cycle stability. Conclusion In summary, we have successfully fabricated an Fe2O3/COOH-MWCNT composite material using ethanolamine and iron chloride hexahydrate as precursors. Fe2O3 nanoparticles with secondary structures were evenly distributed in the COOH-MWCNT network. A reversible capacity of

Thin SnO_x films for surface plasmon resonance enhanced ellipsometric gas sensing (SPREE)

• Daniel Fischer,
• Andreas Hertwig,
• Uwe Beck,
• Volkmar Lohse,
• Detlef Negendank,
• Martin Kormunda and
• Norbert Esser

Beilstein J. Nanotechnol. 2017, 8, 522–529, doi:10.3762/bjnano.8.56

• the problems of cross sensitivity of the MOS concept. Results: Undoped tin oxide (SnOx) and iron doped tin oxide (Fe:SnOx) thin add-on films were prepared by magnetron sputtering on the top of the actual surface plasmon resonance (SPR) sensing gold layer. The films were tested for their sensitivity to

• amount of binding sites for CO in the layer due to this iron doping. For hydrogen (H2) no such relation was found but the sensing ability was identical for both layer materials. This observation was related to a different sensing mechanism for H2 which is driven by the diffusion into the layer instead of

• support the theory of a dependence of the binding sites to the response in the gas measurement, iron doped tin oxide (Fe:SnOx) overcoated sensors with an increased number of binding sites for CO were built [33]. This was achieved by adding a block of metallic iron to the target. A gas sensing measurement

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

• is not observed in other ferromagnetic materials such as nickel and iron. Synthesizing anisotropic and hierarchical nanostructures of cobalt is an effective strategy for tuning its electronic, magnetic and crystal properties. The interest in these nanostructures lies in comprehending the physical and

Self-assembly of silicon nanowires studied by advanced transmission electron microscopy

• Marta Agati,
• Guillaume Amiard,
• Vincent Le Borgne,
• Paola Castrucci,
• Richard Dolbec,
• Maurizio De Crescenzi,
• My Alì El Khakani and
• Simona Boninelli

Beilstein J. Nanotechnol. 2017, 8, 440–445, doi:10.3762/bjnano.8.47

• possess a nanoparticle at their tip. STEM energy dispersive X-ray (EDX) spectroscopy combined with electron tomography performed on these nanostructures revealed that they contain iron, clearly demonstrating that the short ICP-synthesized SiNWs grew via an iron-catalyzed vapor–liquid–solid (VLS) mechanism

• underlying lacey carbon Cu TEM grid used as a supporting substrate for the analysis, representing a background for our study. More interestingly, the presence of Fe was detected in correspondence with the nanoparticle at the tip of the SiNW, while no iron signal was found along the SiNW, within the

• growth of short SiNWs via the above-described ICP process occurs through the VLS mechanism catalyzed by iron nanoparticles. The origin of the nanoparticles is the impurities present in the initial Si powder feedstock (containing 0.18 atom % Fe impurities), while the Si core of the NSs acted as the local

Methods for preparing polymer-decorated single exchange-biased magnetic nanoparticles for application in flexible polymer-based films

• Laurence Ourry,
• Delphine Toulemon,
• Souad Ammar and
• Fayna Mammeri

Beilstein J. Nanotechnol. 2017, 8, 408–417, doi:10.3762/bjnano.8.43

• studied were of iron oxide [9][10][11][12][13][14]. Exchange-biased NPs (ENPs) have been scarcely considered [15] despite their improved magnetic properties. These particles consist of ferro- or ferrimagnetic (F) cores coated with nanocrystalline antiferromagnetic (AF) layers, and exhibit exchange

• applications. Phosphates and phosphonates are suitable for functionalizing iron and silicon oxide surfaces [29][30] through covalent bonds, in mono-, bi- or tridentate modes; but to date, they have not been used for cobalt oxide and ferrite surfaces. In the case of PMMA, we followed two routes: the first one

• catalysts. Masson et al. [35] reported an increase in the styrene polymerization rate, using malonitrile as a catalyst and from initiator molecules anchored on iron oxide NPs. However, it appears that bonding the initiator to the surface through a phosphonate group limits the rate, reducing the effect of

Uptake of the proteins HTRA1 and HTRA2 by cells mediated by calcium phosphate nanoparticles

• Olga Rotan,
• Katharina N. Severin,
• Simon Pöpsel,
• Alexander Peetsch,
• Melisa Merdanovic,
• Michael Ehrmann and
• Matthias Epple

Beilstein J. Nanotechnol. 2017, 8, 381–393, doi:10.3762/bjnano.8.40

• also influence their uptake [64][65][66][67]. Krais et al. have shown that serum proteins were necessary for cancer cells to take up folic acid-conjugated iron oxide nanoparticles [68]. The nature of the protein corona on the protein-loaded calcium phosphate nanoparticles after immersion in cell