Radiation losses in the microwave K_u band in magneto-electric nanocomposites

• Talwinder Kaur,
• Sachin Kumar,
• Jyoti Sharma and
• A. K. Srivastava

Beilstein J. Nanotechnol. 2015, 6, 1700–1707, doi:10.3762/bjnano.6.173

• explained. Further studies revealed that the prepared material is a nanocomposite. FTIR spectra show the presence of expected chemical structures such as C–H bonds in a ring system at 1512 cm−1. Keywords: emulsion polymerization; magneto-electric composite; radiation loss; vector network analyser

• paper, we have used the versatile citrate precursor method to synthesize La–Co-substituted barium hexaferrite. Lanthanum and cobalt are used as substituents to enhance the magnetic properties of barium hexaferrite and then emulsion polymerization is employed for the synthesis of nanocomposites. The

• material (BaM) and aniline are mixed in the ratio of 1:1. The solution is stirred 3–4 h at very low temperature for micelle formation. To initiate the polymerization, ammonium persulfate is used as an initiator that initiates the reaction at 2 °C. The obtained product is filtered with a suction pump and

Atomic force microscopy as analytical tool to study physico-mechanical properties of intestinal cells

• Christa Schimpel,
• Oliver Werzer,
• Eleonore Fröhlich,
• Gerd Leitinger,
• Markus Absenger-Novak,
• Birgit Teubl,
• Andreas Zimmer and
• Eva Roblegg

Beilstein J. Nanotechnol. 2015, 6, 1457–1466, doi:10.3762/bjnano.6.151

• thus responsible for polymerization of monomeric actin to microfilaments and/or the linkage of single microfilaments into hexagonally packed bundles [6][39]. According to the literature, villin is localized at the apex of cells that display a well-developed brush border [40]. In M cells, however

DNA–melamine hybrid molecules: from self-assembly to nanostructures

• Rina Kumari,
• Shib Shankar Banerjee,
• Anil K. Bhowmick and
• Prolay Das

Beilstein J. Nanotechnol. 2015, 6, 1432–1438, doi:10.3762/bjnano.6.148

• could be used for various potential applications including templated polymerization or metallization. Several strategies have been developed to generate self-assembled DNA nanostructures based on DNA–organic hybrid molecular building blocks. The selection of organic molecule and the DNA sequence are 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

• mineralization-directing peptides designed to yield silica coatings in a reliable and predictable manner via precipitation from tetraethoxysilane (TEOS) precursors. Three peptide groups were compared regarding their influence on silica polymerization: (i) two peptide variants with alternating basic and acidic

• residues, i.e. lysine–aspartic acid (KD)x motifs expected to act as charge-relay systems promoting TEOS hydrolysis and silica polymerization; (ii) a tetrahistidine-exposing polypeptide (CA4H4) known to induce silicification due to the positive charge of its clustered imidazole side chains; and (iii) two

Electrical characterization of single molecule and Langmuir–Blodgett monomolecular films of a pyridine-terminated oligo(phenylene-ethynylene) derivative

• Henrry M. Osorio,
• Santiago Martín,
• María Carmen López,
• Santiago Marqués-González,
• Simon J. Higgins,
• Richard J. Nichols,
• Paul J. Low and
• Pilar Cea

Beilstein J. Nanotechnol. 2015, 6, 1145–1157, doi:10.3762/bjnano.6.116

• groups [67][68][69] and fullerenes [60][70][71]. However, many of these groups have significant limitations including chemical degradation at working temperatures [72][73], associated polymerization phenomena [74], small binding energies [74], unexpectedly high contact resistance [75][76][77][78][79][80

In situ observation of biotite (001) surface dissolution at pH 1 and 9.5 by advanced optical microscopy

• Chiara Cappelli,
• Daniel Lamarca-Irisarri,
• Jordi Camas,
• F. Javier Huertas and
• Alexander E. S. Van Driessche

Beilstein J. Nanotechnol. 2015, 6, 665–673, doi:10.3762/bjnano.6.67

• the biotite structure; (2) hydrolysis of the Si–O–Si and Si–O–Al groups of the tetrahedral sheet, responsible for the layer expansion and (3) re-polymerization of Si–OH groups to form Si–O–Si that might cause layer contraction by expulsion of water. In a new concept of the mineral/solution interface

Simple approach for the fabrication of PEDOT-coated Si nanowires

• Mingxuan Zhu,
• Marielle Eyraud,
• Judikael Le Rouzo,
• Nadia Ait Ahmed,
• Florence Boulc’h,
• Claude Alfonso,
• Philippe Knauth and
• François Flory

Beilstein J. Nanotechnol. 2015, 6, 640–650, doi:10.3762/bjnano.6.65

• electrochemical methods. Since the polymerization reaction is a very fast process with regards to monomer diffusion along the SiNW, the conformal deposition by classical, fixed potential deposition was not favored. Instead, the core–shell heterojunction structure was finally achieved by a pulsed deposition method

• . An extremely large shunt resistance was exhibited and determined to be related to the diffusion conditions occurring during polymerization. Keywords: conductive polymer; core–shell structure; electrodeposition; hybrid material; SiNW; Introduction Silicon nanowires (SiNWs) are a current, active

• surface uncovered [16]. In order to improve the junction quality, a conformal PEDOT shell should be introduced to eliminate charge transport paths parallel to the diode. Compared with the spin coating technique, the electrochemical polymerization of PEDOT provides the possibility of excellent polymer

Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

• Ognen Pop-Georgievski,
• Dana Kubies,
• Josef Zemek,
• Neda Neykova,
• Roman Demianchuk,
• Eliška Mázl Chánová,
• Miroslav Šlouf,
• Milan Houska and
• František Rypáček

Beilstein J. Nanotechnol. 2015, 6, 617–631, doi:10.3762/bjnano.6.63

• -aminopropyltriethoxysilane (APTES) can result in several surface structures such as covalent attachment, self-assembly, multilayer formation by surface-initiated (SI) polymerization and particle adsorption [22]. The obstacles and limitations inherent to thiol–SAMs and silanes can be circumvented by the use of moieties

• dopamine and its intermediates (dopamine-quinone, 5,6-dihydroxyindole, etc.), of SI polymerization and of adsorption of the resulting polymer molecules resulted in a 15.2 ± 0.5 nm thick confluent PDA layer. Despite the precautions taken during the APTES deposition for the formation of the SAM [21] (freshly

• surface, but also proves the presence of the siloxane polymer network. The network is formed by SI polymerization from non-hydrolyzed ethoxy groups (which can give rise to silanol groups) and free silanols that did not undergo a dehydration condensation reaction with surface hydroxy groups. Both possible

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• was then activated by silane-carrying methacrylate and 3-(methacryloyloxy)propyltrimethoxysilane (MPTS). Finally, a lightly crosslinked poly(N-isopropylacrylamide) (PNIPAAm) shell was immobilized by a graft polymerization process. The characterization of these NPs was carried out through DLS, TEM, VSM

• -functionalized CdTe QDs were conjugated with the magnetic NPs inside the silica shell. Finally, the silica-coated NPs were wrapped with thermosensitive poly(N-isopropylacrylamide) by a template polymerization process. The average diameter of silica-coated magnetic NPs was found to be 100 ± 10 nm as studied by

• nanocomposite material composed of a magnetic silica core and a fluorescent shell by combining two different techniques, namely heterocoagulation and soap-free emulsion polymerization. The N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TSA)-modified Fe3O4 NPs were prepared by the Massart method and

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

• particles were fluorescently labeled with the fluorescent dye N-(2,6-diisopropylphenyl)perylene-3,4-dicarboximide (PMI). The magnetite was encapsulated for magnetic resonance purposes. The polymeric nanoparticles used in this work were obtained by miniemulsion polymerization (non-functionalized and

Comparative evaluation of the impact on endothelial cells induced by different nanoparticle structures and functionalization

• Lisa Landgraf,
• Ines Müller,
• Peter Ernst,
• Miriam Schäfer,
• Christina Rosman,
• Isabel Schick,
• Oskar Köhler,
• Hartmut Oehring,
• Vladimir V. Breus,
• Thomas Basché,
• Carsten Sönnichsen,
• Wolfgang Tremel and
• Ingrid Hilger

Beilstein J. Nanotechnol. 2015, 6, 300–312, doi:10.3762/bjnano.6.28

• endocytotic processes were assessed. SVEC4-10 cells were pre-incubated with 5 µg/mL cytochalasin D (inhibitor of actin polymerization, indicator of caveolae and macropinocytosis) [74], 100 nM wortmannin (inhibitor of PI3 kinase, indicator of macropinocytosis) [75], 5 µg/mL nocodazol (promotes microtubule

Tailoring the ligand shell for the control of cellular uptake and optical properties of nanocrystals

• Johannes Ostermann,
• Christian Schmidtke,
• Christopher Wolter,
• Jan-Philip Merkl,
• Hauke Kloust and
• Horst Weller

Beilstein J. Nanotechnol. 2015, 6, 232–242, doi:10.3762/bjnano.6.22

• against dilution can be achieved. By carefully choosing the monomers, reaction conditions and block length ratios it is possible to reproducibly synthesize very defined ligands, using anionic polymerization techniques [10]. One advantage of this reaction type is the absence of chain transfer and

• Ligand synthesis The synthesis of amphiphilic polyisoprene-block-poly(ethylene glycol) (PI-b-PEG) was realized via anionic polymerization, using standard high vacuum reaction techniques [10][20]. Isoprene was polymerized in dry THF by the quick addition of sec-butyllithium at −40 °C. After completion of

• solvate separated ion pair, which is capable of starting the polymerization of ethylene oxide at room temperature (Scheme 1). Using this reaction path a variety of PI homopolymers and PI-b-PEG diblock copolymers differing in size and block length ratio were synthesized (Table 1). The aggregation of the PI

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• and it might be worthwhile to further investigate it [71]. BNNT-grafted, poly(glycidyl methacrylate) and polystyrene brushes were prepared via atom transfer radical polymerization [72]. The resulting nanocomposite material was characterized using FTIR, TGA, SEM and TEM. The TEM images clearly show the

Poly(styrene)/oligo(fluorene)-intercalated fluoromica hybrids: synthesis, characterization and self-assembly

• Giuseppe Leone,
• Francesco Galeotti,
• William Porzio,
• Guido Scavia,
• Luisa Barba,
• Gianmichele Arrighetti,
• Giovanni Ricci,
• Chiara Botta and
• Umberto Giovanella

Beilstein J. Nanotechnol. 2014, 5, 2450–2458, doi:10.3762/bjnano.5.254

• powders by synchrotron radiation XRD. Successively, the hybrids are dispersed in poly(styrene) through in situ polymerization. Such a procedure allows us to synthesize the materials from solution, to achieve solid films, and to characterize them by optical and morphologic techniques. The polymeric films

• (styrene) (PS) matrix by in situ thermal polymerization. Such a procedure allowed us to process the materials as solid films and to characterize them by optical, structural, and morphologic analyses. In addition, we explored the possibility of organizing these materials in ordered honeycomb structures

• material in solution, we believed that an intriguing strategy would be to use a polymer as dispersing agent. Our previous results [8][9][10] caused us to regard the in situ polymerization as a potent tool to improve the intimate mixing between the polymer and the inorganic component. Thus, we synthesized

Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

• Cornelia Loos,
• Tatiana Syrovets,
• Anna Musyanovych,
• Volker Mailänder,
• Katharina Landfester,
• G. Ulrich Nienhaus and
• Thomas Simmet

Beilstein J. Nanotechnol. 2014, 5, 2403–2412, doi:10.3762/bjnano.5.250

• aromatic polymer obtained by polymerization of styrene monomers (Figure 1). For the industrial mass production of polystyrene, styrene monomers are produced by the catalytic dehydrogenation of ethylbenzene which, in turn, is synthesized by the petrochemical industry [1]. Commonly used polystyrene is being

• this size occurs in a specific, receptor-mediated manner, which is characterized by the polymerization of clathrin units, membrane deformation, and intracellular signaling, which could all be integrated into a mathematical model describing these processes [28]. Of note, depending on the nature of the

Nanoparticle interactions with live cells: Quantitative fluorescence microscopy of nanoparticle size effects

• Li Shang,
• Karin Nienhaus,
• Xiue Jiang,
• Linxiao Yang,
• Katharina Landfester,
• Volker Mailänder,
• Thomas Simmet and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2388–2397, doi:10.3762/bjnano.5.248

• -(2,6-diisopropylphenyl)-perylene-3,4-dicarbonacidimide (PMI, BASF, Ludwigshafen, Germany), were synthesized by a miniemulsion polymerization approach [30]. Cell culture HeLa cells were cultured in Dulbecco’s modified eagle medium (DMEM), supplemented with 10% fetal bovine serum (FBS), 60 µg/mL

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

• amphiphilic particle. Kumacheva et al. reported a microfluidic method for fast continuous synthesis of Janus particles as well as three-phase particles with narrow size distribution by emulsification of monomer liquids and in situ photoinitiated polymerization of multiphase droplets (Figure 3e) [27]. Another

• complex core (IPEC), (c) classical Pickering emulsion technique, (d) different topologies of Janus particles: snowman-, acorn-, and dumbbell-like nanoparticles (top to bottom), (e) microfluidic photo-polymerization system, and (f) electrospinning technique with a bi-phasic nozzle. Reproduced with

Anticancer efficacy of a supramolecular complex of a 2-diethylaminoethyl–dextran–MMA graft copolymer and paclitaxel used as an artificial enzyme

• Yasuhiko Onishi,
• Yuki Eshita,
• Rui-Cheng Ji,
• Masayasu Onishi,
• Takashi Kobayashi,
• Masaaki Mizuno,
• Jun Yoshida and
• Naoji Kubota

Beilstein J. Nanotechnol. 2014, 5, 2293–2307, doi:10.3762/bjnano.5.238

• the genetic engineering serves as an important domain [11]. The copolymer that was used for graft polymerization of MMA onto DEAE–dextran formed a polymer micelle with a hydrophilic–hydrophobic micro-separated domain. The high transformation efficiency of this polymer micelle suggests that it could be

• of melanoma cells. However, at high concentrations, survival is inversely proportional to the PTX concentration. Truly, at high concentrations, PTX will be efficacious, and the promotion of tubulin polymerization by PTX, which is dependent on the PTX concentration, for a negative survival probability

• (Cd) rate (Cd/dt) and tubulin polymerization (p) rate (dp/dt) will assume the following equation, as modified from the Cheng and Prusoff equation [38][39][40]: where, a is a constant value and C1 is a device constant (a > 0, C1 > 0). Michaelis–Menten kinetics The Michaelis–Menten equation assumes an

Characterization of 10,12-pentacosadiynoic acid Langmuir–Blodgett monolayers and their use in metal–insulator–metal tunnel devices

• Saumya Sharma,
• Mohamad Khawaja,
• Manoj K. Ram,
• D. Yogi Goswami and
• Elias Stefanakos

Beilstein J. Nanotechnol. 2014, 5, 2240–2247, doi:10.3762/bjnano.5.233

• the top contact sputtering. Recently, Langmuir monolayer films of 10,12-pentacosadiynoic acid (PDA) were studied as reported in the literature [8][10][11]. A set of experiments were performed regarding the photo-polymerization of PDA monomers using in situ UV light exposure in the LB trough as well as

• controlled using the KSV NIMA LB Trough controller. For polymerization purposes, the monolayers were exposed to 245 nm UV radiation for 15 min using a UV bench lamp [17]. Optical characterization: A Jasco FTIR 4600 was used to perform IR spectroscopy on the PDA film in transmission mode. IR transparent Si

• film compression was studied. Figure 2 shows the pressure–area isotherm of the PDA Langmuir monolayer with and without in situ polymerization in the trough at the air–water interface. The UV-exposed Langmuir monolayer shows a more compressed area for the same volume of PDA solution dispersed in water

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• with (3-aminopropyl)trimethoxysilane (APTMS), (b) DNA deposition on the cationic particle surface, (c) CdS precipitation, and (d) dissolution of the SiO2 core to form hollow structures. Reprinted with permission from [52]. Copyright 2011 American Chemical Society. Siloxan polymerization on chitosan

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

• . Interestingly, the CNO-OH showed distinct fluorescence emission with an emission maximum at 453 nm in aqueous solution, while CNO-Br did not fluoresce. Based on these two CNO derivatives, the authors reported different polymerization reactions, where the CNOs served as macroinitiators. Firstly, CNO-OHs were

• used for a ring opening polymerization with ε-caprolactone in the presence of stannous octoate. In a second approach, CNO-Brs were decorated with polystyrene in an atom transfer radical polymerization reaction. Both polymer-functionalized CNO materials showed a good solubility in common organic

• in the presence of ascorbic acid and uric acid in solution [44]. The concentration of dopamine could be determined in a range between 5 × 10−5 and 4 × 10−3 mol·L−1. They also reported the in situ polymerization of aniline on phenylene amine-terminated CNO derivatives [45]. This polyaniline (PANI

Towards bottom-up nanopatterning of Prussian blue analogues

• Virgile Trannoy,
• Marco Faustini,
• David Grosso,
• Sandra Mazerat,
• François Brisset,
• Alexandre Dazzi and
• Anne Bleuzen

Beilstein J. Nanotechnol. 2014, 5, 1933–1943, doi:10.3762/bjnano.5.204

• between hexacyanometalates and hydrated cations of the transition metal series in aqueous solution. The resulting solid exhibits the well-known face centered cubic structure of Prussian blue [9]. The sol–gel process is a method for producing metal oxides from small molecules via inorganic polymerization

Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

• Michal Babič,
• Daniel Horák,
• Lyubov L. Lukash,
• Tetiana A. Ruban,
• Yurii N. Kolomiets,
• Svitlana P. Shpylova and
• Oksana A. Grypych

Beilstein J. Nanotechnol. 2014, 5, 1732–1737, doi:10.3762/bjnano.5.183

• by sodium hypochlorite and the coating with D-mannose and poly(N,N-dimethylacrylamide) according to earlier reports [20][25]. While coating with D-mannose was performed by the slow addition of D-mannose solution to the γ-Fe2O3 colloid, coating with PDMAAm included solution radical polymerization of N

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

• favorably exploited for CNTs precipitation/dispersion cycles. Ortiz-Acevedo et al. obtained a diameter-selective solubilization of SWCNTs by using cyclic peptides containing thiol groups [101]. The oxidation induces polymerization of the peptides which wrap around the nanotube achieving a size-selective

Different endocytotic uptake mechanisms for nanoparticles in epithelial cells and macrophages

• Dagmar A. Kuhn,
• Dimitri Vanhecke,
• Benjamin Michen,
• Fabian Blank,
• Peter Gehr,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2014, 5, 1625–1636, doi:10.3762/bjnano.5.174

• caveolin-1. A549 cells expressed clathrin heavy chain and caveolin-1, but no flotillin-1 uptake-related proteins. Our data revealed an impeded uptake of 40 nm polystyrene nanoparticles by J774A.1 macrophages when actin polymerization and clathrin-coated pit formation was blocked. From this result, it is

• inhibited clathrin- as well as caveolin-mediated endocytosis as shown by the lack of intracellular fluorescently labelled transferrin and ctx-b in A549 cells. The actin polymerization inhibitor cytochalasin D prevented particle uptake (d = 1 µm) by J774A.1 cells at a concentration of 4 µM. Uptake of

• high as expected for A549 cells. This could be due to cytochalasin D blocking actin polymerization and hence preventing Trypan blue from entering the cells, although the cells are severely affected by this inhibitor. It was shown that the optimal and desired function of the endocytotic inhibitors was