Properties of Ni and Ni–Fe nanowires electrochemically deposited into a porous alumina template

• Alla I. Vorobjova,
• Dmitry L. Shimanovich,
• Kazimir I. Yanushkevich,
• Sergej L. Prischepa and
• Elena A. Outkina

Beilstein J. Nanotechnol. 2016, 7, 1709–1717, doi:10.3762/bjnano.7.163

• in aqueous solution of oxalic acid (H2C2O4, 0.3 M) at 15 °C. The first stage of anodization was performed under a constant voltage of 50 ± 5 V for 25 min. After the first anodization, the preformed oxide film was removed by wet chemical etching in a mixture of phosphoric acid (H3PO4, 0.5 M) and

Influence of hydrothermal synthesis parameters on the properties of hydroxyapatite nanoparticles

• Sylwia Kuśnieruk,
• Jacek Wojnarowicz,
• Agnieszka Chodara,
• Tadeusz Chudoba,
• Stanislaw Gierlotka and
• Witold Lojkowski

Beilstein J. Nanotechnol. 2016, 7, 1586–1601, doi:10.3762/bjnano.7.153

• used was Ca/P 1.67. Phosphoric acid was added dropwise to the water suspension of calcium hydroxide at a rate of 0.01 mL every 0.5 s (Titrator, SI Analytics, Titronic universal, TZ3260, Germany); hydroxyapatite was formed with the following reaction scheme: The hydroxyapatite precipitate was

• to the stirring of the heated reagents during the microwave reaction, which determines the homogeneity of the obtained products. Precursor stirring during the synthesis in the MSS2 reactor is spontaneous and results from the temperature gradient in the reaction chamber. Stirring, phosphoric acid

• phosphoric acid solution should be moderate (below 100 mL/min), while the reaction temperature should be kept lower than 60 °C. Only then will the reaction ensue at 100% and the SSA of the obtained HAp will be ≈75 m2/g. If the speed of adding the phosphoric acid is very high, the pH value in the reaction

Voltammetric determination of polyphenolic content in pomegranate juice using a poly(gallic acid)/multiwalled carbon nanotube modified electrode

• Refat Abdel-Hamid and
• Emad F. Newair

Beilstein J. Nanotechnol. 2016, 7, 1104–1112, doi:10.3762/bjnano.7.103

• day of preparation. Pure nitrogen was used for degassing the test solution prior to and throughout the electrochemical measurements. Phosphoric acid solution was used as a supporting electrolyte. Double-distilled water was used for preparation of all solutions. Freshly prepared standard solutions of

• gallic acid were prepared by dilution of the stock solution with 0.2 M phosphoric acid. Instrumentation Cyclic and square wave voltammetric, chronoamperomeric and chronocoulomeric experiments were performed by using an Autolab PGSTAT128N Potentiostat/Galvanostat (Eco-Chemie, Utrecht, The Netherlands

• voltammograms of 1.0 mM GA in 0.2 M H3PO4 at a scan rate of 50 mV s−1 on bare GCE, PGA/GCE, MWCNT/GCE and PGA/MWCNT/GCE. Relationship of i(t < τ) vs (t−1/2) chronoamperometry of 1.0 mM K3[Fe(CN)6] in 0.2 M KCl on (A) GCE and (B) PGA/MWCNT/GCE. Chronoamperograms of PGA/MWCNT/GCE in 0.2 M phosphoric acid in

Large-scale fabrication of achiral plasmonic metamaterials with giant chiroptical response

• Morten Slyngborg,
• Yao-Chung Tsao and
• Peter Fojan

Beilstein J. Nanotechnol. 2016, 7, 914–925, doi:10.3762/bjnano.7.83

• nm. The substrate with 300 nm interpore distance was prepared by anodization in 0.3 M oxalic acid solution at 140 V and with a solution temperature of 283 ± 0.5 K for 40 min. The substrate with 430 nm interpore distance was prepared by anodization in 1 M phosphoric acid solution at 180 V and with a

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

Electrochemical coating of dental implants with anodic porous titania for enhanced osteointegration

• Amirreza Shayganpour,
• Alberto Rebaudi,
• Pierpaolo Cortella,
• Alberto Diaspro and
• Marco Salerno

Beilstein J. Nanotechnol. 2015, 6, 2183–2192, doi:10.3762/bjnano.6.224

• anions PO42− entrapped within the porous oxide during its growth. Actually, this is the reason why we decided to use phosphoric acid as the anodizing electrolyte, since phosphate is likely to be biocompatible and even bioactive in the foreseen application of the coatings for osteointegration, due to its

• from the anodization did not alter the underlying surface profile on the microscale. Therefore, when not sufficient to provide osteointegration by itself, anodization can be an additive treatment in addition to microscale sandblasting or wet etching. By anodizing in phosphoric acid, a remarkable doping

• implants. Anodization The implants were suspended vertically upside-down and submerged in a 1.5 M aqueous solution of phosphoric acid H3PO4 (Sigma Aldrich, Milan, Italy). The counter electrode (normally the cathode) was an inert Pt wire (1 mm thickness), curled in a spiral to form an almost compact circle

Nanofibers for drug delivery – incorporation and release of model molecules, influence of molecular weight and polymer structure

• Jakub Hrib,
• Jakub Sirc,
• Radka Hobzova,
• Zuzana Hampejsova,
• Zuzana Bosakova,
• Marcela Munzarova and
• Jiri Michalek

Beilstein J. Nanotechnol. 2015, 6, 1939–1945, doi:10.3762/bjnano.6.198

• were obtained from Sigma, St. Louis, MO, USA. PVA was provided by Nippon Gohsei, Osaka, Japan. PLA (Mw ≈ 100 kDa) was kindly provided as a sample from Natureworks, Blair, NE, USA. Phosphoric acid (85 wt % aqueous solution), N,N-dimethylformamide, tetrahydrofuran and dichloromethane were obtained from

• . PVA was dissolved in water/phosphoric acid at a concentration of 11 wt %. The electrospinning parameters were 2 rpm, 13 cm and 45–55 kV/cm. The relative humidity was 25–30%, and the temperature was 22 °C. The PVA layers were crosslinked thermally in a drying oven at 145 °C for 15 min to reach their

Scalable, high performance, enzymatic cathodes based on nanoimprint lithography

• Dmitry Pankratov,
• Richard Sundberg,
• Javier Sotres,
• Dmitry B. Suyatin,
• Ivan Maximov,
• Sergey Shleev and
• Lars Montelius

Beilstein J. Nanotechnol. 2015, 6, 1377–1384, doi:10.3762/bjnano.6.142

• -interference lithography. The stamp had undergone an anti-sticking treatment, resulting in a thin monolayer, self-assembling film of fluorinated alkyl phosphoric acid derivatives, as described in [27]. The pattern transfer step included imprinting using a 6" imprinter machine from Obducat Technologies AB (Lund

X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

• Toma Susi,
• Thomas Pichler and
• Paola Ayala

Beilstein J. Nanotechnol. 2015, 6, 177–192, doi:10.3762/bjnano.6.17

• also been successful to a certain extent, by using ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [191]. In addition, the synthesis of P/N-heterodoped graphene has been reported using triphenylphosphine and triphenylamine [100] and by chemical treatment of N-graphene using phosphoric acid

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• components. A conventional high-temperature membrane electrode assembly (HT-MEA) primarily consists of a polybenzimidazole (PBI)-type membrane containing phosphoric acid and two gas diffusion electrodes (GDE), the anode and the cathode, attached to the two surfaces of the membrane. This review article

• exhibit high proton conductivity in low-hydration and even anhydrous states. Of special concern for phosphoric-acid-doped PBI-type membranes is the acid loss and management during operation. The slow oxygen reduction reaction in HT-PEMFCs remains a challenge. Phosphoric acid tends to adsorb onto the

• ; characterization techniques; high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC); membrane electrode assembly (MEA); phosphoric acid-doped polybenzimidazole (PBI); Introduction Fuel cells are among the enabling technologies toward a safe, reliable, and sustainable energy solution. Yet, the lack of

Electrostatic interplay: The interaction triangle of polyamines, silicic acid, and phosphate studied through turbidity measurements, silicomolybdic acid test, and ²⁹Si NMR spectroscopy

• Anne Jantschke,
• Katrin Spinde and
• Eike Brunner

Beilstein J. Nanotechnol. 2014, 5, 2026–2035, doi:10.3762/bjnano.5.211

• diluted to a Si-concentration of 120 mM. Preparation of solution A with phosphate: Solution A was prepared as described by using 0.5 M phosphoric acid for titration (see final concentration in Table 3). Finally, the samples were diluted to a Si-concentration of 120 mM. Preparation of solution B: The amine

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

• that zinc oxide can react with phosphoric acid to form various zinc phosphates which have applications, e.g., as dental cement [2]. Zinc phosphate can also be used as corrosion inhibitor for metals as it forms a protecting layer on metal surfaces [3]. This usage is possible because of the low

Liquid fuel cells

• Grigorii L. Soloveichik

Beilstein J. Nanotechnol. 2014, 5, 1399–1418, doi:10.3762/bjnano.5.153

• hydrocarbons (octane, decane, and, eventually, diesel fuel) as a fuel in phosphoric acid fuel cells. Linear hydrocarbons produced a higher current density on a Pt/PTFE anode in 95 wt % phosphoric acid at 175 °C while the addition of aromatic or branched hydrocarbons increased the anode overpotential [42]. On

• decreased the cell performance to about a third. Electrooxidation of hydrocarbon fuels in the presence of phosphoric acid requires a very high Pt loading (50 mg Pt/cm2), which makes this approach unfeasible. Lower hydrocarbons, e.g., propane [44][45] and cyclohexane [46][47] were used as fuels for PEM fuel

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

• times of the process. The degradation of CuPc was analyzed by high performance liquid chromatography (HPLC; Waters Alliance 2975 equipped with a Waters 996 Photodiode Array Detector; UV–vis detection), using a C8 column (Waters Symmetry: 150 × 4.6 mm, 3.5 μm). The mobile phases were 0.1% aq phosphoric

• acid (A), and acetonitrile (B), run in a linear gradient (80:20, v/v) at a flow rate of 1 mL/min. XRD pattern of the nanoparticles, indicating that pyrite was the only crystalline phase resulting from the synthesis. Rietveld analysis of the reflection broadening gave an average crystallite size of 20

Volcano plots in hydrogen electrocatalysis – uses and abuses

• Paola Quaino,
• Fernanda Juarez,
• Elizabeth Santos and
• Wolfgang Schmickler

Beilstein J. Nanotechnol. 2014, 5, 846–854, doi:10.3762/bjnano.5.96

• energies is not perfect. As for experimental data, there is one consistent set of data for the oxygen reduction in 85% phosphoric acid; this was once a popular solution because of the phosphoric acid fuel cell. We have plotted the corresponding data in the same figure. There are some obvious similarities

• hydrogen evolution. Oxygen reduction on various substrates in acid solutions. Left: logarithm of the current at 800 mV NHE in 85% phosphoric acid at 25°C plotted versus the adsorption energy of OOH on (111) surfaces; experimental data from Appleby [39], adsorption energies from [37]. Right: electrode

Preparation of electrochemically active silicon nanotubes in highly ordered arrays

• Tobias Grünzel,
• Young Joo Lee,
• Karsten Kuepper and
• Julien Bachmann

Beilstein J. Nanotechnol. 2013, 4, 655–664, doi:10.3762/bjnano.4.73

• . Subsequently (b), the diameter of the pores is increased from its initial value of 40 nm to approximately 60 nm by an isotropic wet chemical etching in warm phosphoric acid. This step maximizes the space available for the electrochemically active material inside the inert matrix. The inner pore walls are

• coated by ALD (c) by using 3-aminopropyltriethoxysilane, water, and ozone at 150 °C [17][18]. The underlying metallic aluminum substrate is removed oxidatively (d), and the the so-called barrier layer of oxide closing the pore extremities is opened in warm phosphoric acid (e), which leaves a free

• , phosphoric acid, copper(II) chloride dihydrate, chromium(VI) oxide, ethanol, hydrochloric acid, perchloric acid, argon, and dioxygen, were purchased from commercial suppliers and used as received. Ozone was generated from dioxygen in a generator BMT 803N from BMT Messtechnik. Aluminum (99.999%) was purchased

Novel composite Zr/PBI-O-PhT membranes for HT-PEFC applications

• Mikhail S. Kondratenko,
• Igor I. Ponomarev,
• Marat O. Gallyamov,
• Dmitry Y. Razorenov,
• Yulia A. Volkova,
• Elena P. Kharitonova and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 481–492, doi:10.3762/bjnano.4.57

• with Zr facilitated an increase of the phosphoric acid (PA) uptake by the membranes, which resulted in an up to 2.5 times increased proton conductivity. The existence of an optimal amount of Zr content in the modified PBI-O-PhT film was shown. Larger amounts of Zr lead to a lower PA doping level and a

• ) membranes doped with phosphoric acid (PA) as an electrolyte can be operated without any humidification of reactant gases at an elevated temperature range, in which the CO tolerance of the Pt catalyst becomes higher. This allows the use of cheap hydrogen fuel, which was not thoroughly purified, such as

• level of several phosphoric acid molecules per PBI monomer unit. Only one PA molecule is really bound to the protonated N-atom, the other molecules are retained by hydrogen bonds. This acid–base bonding requires an immobilized proton to be excluded from the proton transport. In contrast, the direct

Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores

• Thomas D. Lazzara,
• K. H. Aaron Lau,
• Wolfgang Knoll,
• Andreas Janshoff and
• Claudia Steinem

Beilstein J. Nanotechnol. 2012, 3, 475–484, doi:10.3762/bjnano.3.54

• . Louis, MO, USA). (3-Aminopropyl)triethoxysilane (APTES) was purchased from Fluka (Steinheim, Germany). Oxalic acid dihydrate was from AppliChem (Darmstadt, Germany) and phosphoric acid 85% was purchased from Acros Chemicals (New Jersey, NJ, USA). Al foil (0.25 mm thick, purity: 99.999%) was purchased

• ensured highly ordered pores with a low pore-diameter (d0) size distribution (Scheme 1, bottom). The resulting AAO substrates had an interpore distance of p = 95–105 nm and a thickness of h = 3.2–3.8 µm, while the pore diameters were tuned between d0 = 25–80 nm by isotropic pore-widening in phosphoric

• acid. Before pore diameter adjustment, they were covered with a thin metal coupling layer on the aluminum oxide barrier side (bottom) and then mounted on glass supports by using an optical adhesive [34]. This allowed the characterization of the AAO refractive index and the in situ monitoring of the

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

• solvents from aprotic to protic, and even in water. In line with the above discussion, we synthesized an initiator carrying a phosphoric acid group, 8-(2-bromo-2-methylpropanoyloxy) octyl phosphoric acid (BMPOPO4H2), which was further converted to a water-soluble ammonium salt [BMPOPO4(NH4)2]. Figure 11

Microfluidic anodization of aluminum films for the fabrication of nanoporous lipid bilayer support structures

• Jaydeep Bhattacharya,
• Alexandre Kisner,
• Andreas Offenhäusser and
• Bernhard Wolfrum

Beilstein J. Nanotechnol. 2011, 2, 104–109, doi:10.3762/bjnano.2.12

• the anodization was indicated by a steep drop in the anodization current indicating the formation of a residual alumina barrier layer. Oxalic acid was then rinsed from the channel and 5% phosphoric acid injected into the upper and lower channels to remove the remaining alumina film at the bottom of

• under a constant flow of oxalic acid inside a microfluidic cell to form a nanoporous alumina membrane. C) After the anodization is complete, the remaining alumina at the bottom of the pores is opened by injecting phosphoric acid into both fluidic channels. SEM images of the nanoporous alumina film