Nanostructured SnO₂–ZnO composite gas sensors for selective detection of carbon monoxide

• Paul Chesler,
• Cristian Hornoiu,
• Susana Mihaiu,
• Cristina Vladut,
• Jose Maria Calderon Moreno,
• Mihai Anastasescu,
• Carmen Moldovan,
• Bogdan Firtat,
• Costin Brasoveanu,
• George Muscalu,
• Ion Stan and
• Mariuca Gartner

Beilstein J. Nanotechnol. 2016, 7, 2045–2056, doi:10.3762/bjnano.7.195

• . It can be observed from Figure 8 that the samples with the highest degree of porosity are S2 and S4. This is a promoting factor for the overall sensing process as more sites for gas adsorption are available for this sample in comparison with the other prepared samples. The large grains observed for

• , as previously reported in literature [36]. The result may be interpreted using the SEM images of the sensitive films, shown in Figure 8. The film with the highest degree of porosity is also the most active film (S2) towards CO detection. An additional study was previously published by the authors of

• particular sample (S2, containing 2% SnO2 and 98% ZnO) had a very high porosity – a feature which promotes the gas adsorption on the surface sites, improving the overall sensing properties of the studied material. The response of the obtained sensors was tested by exposure to different gases. The sensor

Organoclay hybrid materials as precursors of porous ZnO/silica-clay heterostructures for photocatalytic applications

• Marwa Akkari,
• Pilar Aranda,
• Abdessalem Ben Haj Amara and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2016, 7, 1971–1982, doi:10.3762/bjnano.7.188

• calcination under the same conditions but without assembling of ZnO NP (Table 1). Anyway, as it occurs with other related materials affected by delamination processes, the solids prepared here exhibit higher values of total porosity and specific surface area than ZnO-clay heterostructures, which is of

• -sepiolite and ZnO/silica-sepiolite heterostructures, respectively, can be seen. This decrease in surface area can be attributed to the presence of ZnO NP, which partially blocks the tunnels of the sepiolite as well as the porosity created by the SiO2 NP attached to sepiolite. A collapse of sepiolite after

Ferromagnetic behaviour of ZnO: the role of grain boundaries

• Boris B. Straumal,
• Svetlana G. Protasova,
• Andrei A. Mazilkin,
• Eberhard Goering,
• Gisela Schütz,
• Petr B. Straumal and
• Brigitte Baretzky

Beilstein J. Nanotechnol. 2016, 7, 1936–1947, doi:10.3762/bjnano.7.185

• . We added an experimental point to the diagrams in Figure 1 if it was possible to estimate from the published experimental work (a) the grain size, (b) the grain shape – equiaxial, elongated or flattened – and (c) porosity of sample, i.e., the portion of grain boundaries and free surfaces. When

• the porosity factor p < 1. In the upper horizontal axis the values of grain size are given as recalculated from sGB supposing that the sample is dense and the grains are equiaxial. Squares correspond to the single crystalline samples. They do not contain any GBs, therefore, we put them in the diagram

Morphology of SiO₂ films as a key factor in alignment of liquid crystals with negative dielectric anisotropy

• Volodymyr Tkachenko,
• Antigone Marino,
• Eva Otón,
• Noureddine Bennis and
• Josè Manuel Otón

Beilstein J. Nanotechnol. 2016, 7, 1743–1748, doi:10.3762/bjnano.7.167

• interest in photonics because of porosity dependence on the deposition angle, and consequently low and controllable refractive index. Many research groups have studied such films with ellipsometry techniques [16][17][18]. Some of them [16][17] investigated porosity and refractive index without taking into

• dielectric function εj of porous SiO2 layers was described using the effective media theory of Bruggeman [24], generalized for ellipsoidal inclusions of two components which are equally oriented and randomly dispersed [25]: Here p is the porosity (volume fraction of pore), ε1 = 1 is the permittivity of air

• described by the Cauchy dispersion formula. Porosity, Lj, βSiO2, βLC, thicknesses of SiO2 and LC layers and the Cauchy parameters were found by experimental fits. Even though the values of φSiO2 and φLC were less than 1°, we fit them to improve accuracy of the desired physical quantities. Results and

The effect of dry shear aligning of nanotube thin films on the photovoltaic performance of carbon nanotube–silicon solar cells

• Benedikt W. Stolz,
• Daniel D. Tune and
• Benjamin S. Flavel

Beilstein J. Nanotechnol. 2016, 7, 1486–1491, doi:10.3762/bjnano.7.141

• important factor in many devices is the degree of coverage of the films on the silicon surface, itself dependent on the films’ porosity. Jung et al. [17], Li et al. [28] and Tune et al. [42] have shown that alignment of the nanotubes by solution shearing (as known as slide casting, liquid film shearing

• films as captured on the filtration membranes, and the same films after DSA. As well as the obvious alignment of the nanotubes in the direction of shear, the porosity of the film has also been reduced due to better packing of the nanotubes in their aligned configuration. The films are now also visibly

Photothermal effect of gold nanostar patterns inkjet-printed on coated paper substrates with different permeability

• Mykola Borzenkov,
• Anni Määttänen,
• Petri Ihalainen,
• Maddalena Collini,
• Elisa Cabrini,
• Giacomo Dacarro,
• Piersandro Pallavicini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2016, 7, 1480–1485, doi:10.3762/bjnano.7.140

• requires the ability to maintain high efficiency and tunability of the NIR LSPR of the printed nanoparticles. In this study stable inks containing PEGylated gold nanostars (GNS) were fabricated and successfully inkjet-printed onto differently coated paper substrates with different porosity and permeability

• commonly employed material that combines low-cost and excellent environmental compatibility [20]. Furthermore, the physical and chemical properties of this superb printing substrate (e.g., topography, roughness, stiffness, surface energy, polarity, porosity and pore geometry) can be easily tailored by

• porosity and permeability as measured in Gurley seconds: substrate 1 (>40000 Gurley seconds, semi-permeable, two coating layers ), substrate 2 (7360 Gurley seconds, permeable, calcium carbonate (major component) and kaolin coating) and substrate 3 (non-permeable, latex coating). The PEG-decorated GNS were

Polystyrene-block-poly(ethylene oxide) copolymers as templates for stacked, spherical large-mesopore silica coatings: dependence of silica pore size on the PS/PEO ratio

• Roberto Nisticò,
• Giuliana Magnacca,
• Sushilkumar A. Jadhav and
• Dominique Scalarone

Beilstein J. Nanotechnol. 2016, 7, 1454–1460, doi:10.3762/bjnano.7.137

• narrow pore size distribution and high porosity have been obtained by a sol–gel reaction of a silicon oxide precursor (TEOS) and using polystyrene-block-poly(ethylene oxide) (PS-b-PEO) copolymers as templates in an acidic environment. PS-b-PEO copolymers with different molecular weight and composition

• between the hydrophilic/hydrophobic ratio of the two polymer blocks and the size of the final silica pores. The obtained results prove that by tuning the PS/PEO ratio, the pore size of the templated silica films can be easily and finely predicted. Keywords: block copolymers; controlled porosity

• ; mesoporous silica; soft templating; sol–gel; Introduction Mesoporous materials with large, tunable porosity are currently being investigated as selective molecular sieves, finding potential applications in many fields such as catalysis, encapsulation of proteins, filtration and separation of large molecules

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal

• Eduardo Aluicio-Sarduy,
• Simone Callegari,
• Diana Gisell Figueroa del Valle,
• Andrea Desii,
• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2016, 7, 1404–1410, doi:10.3762/bjnano.7.131

• silver/titanium dioxide interface. These charges contribute to the plasma frequency of silver, which due to the porosity of the layer and the subsequent high surface/volume ratio, will allow the electron density to increase over the entire volume of the silver layer, resulting in an increase of the

Dealloying of gold–copper alloy nanowires: From hillocks to ring-shaped nanopores

• Adrien Chauvin,
• Cyril Delacôte,
• Mohammed Boujtita,
• Benoit Angleraud,
• Junjun Ding,
• Chang-Hwan Choi,
• Pierre-Yves Tessier and
• Abdel-Aziz El Mel

Beilstein J. Nanotechnol. 2016, 7, 1361–1367, doi:10.3762/bjnano.7.127

• 0.3 V (Figure 5e), only tiny pores form around the hillocks. The limited porosity is probably related to a surface passivation effect due to the relatively high initial content of Au. Further increasing the dealloying voltage to 0.4 V (Figure 5f) results in the generation of nanoporosity very similar

• to the one observed in case of Au–Cu nanowires not containing any sort of hillocks [24]. Increasing the dealloying voltage to 0.5 V results in an increase in the porosity within the material (Supporting Information File 1, Figure S4). Conclusion To summarize, we have shown the benefit of using

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

Manufacturing and investigation of physical properties of polyacrylonitrile nanofibre composites with SiO₂, TiO₂ and Bi₂O₃ nanoparticles

• Tomasz Tański,
• Wiktor Matysiak and
• Barbara Hajduk

Beilstein J. Nanotechnol. 2016, 7, 1141–1155, doi:10.3762/bjnano.7.106

• obtained composite mats, reinforced with silicon oxide, are a promising starting material that can be used to produce carbon anodes, which are used in lithium-ion batteries, after their subsequent treatment by carbonisation and chemical removal of the reinforcing phases in order to increase the porosity of

Hierarchical coassembly of DNA–triptycene hybrid molecular building blocks and zinc protoporphyrin IX

• Rina Kumari,
• Sumit Singh,
• Mohan Monisha,
• Sourav Bhowmick,
• Anindya Roy,
• Neeladri Das and
• Prolay Das

Beilstein J. Nanotechnol. 2016, 7, 697–707, doi:10.3762/bjnano.7.62

• , tailorability, high efficacy and biological relevancy. Conjugation of TPA with oligomeric DNA results in tuned material property and porosity of the nanostructures. Such methodology offers a new opportunity for the construction of composite nanostructures by the positioning of a guest molecule on DNA–TPA hybrid

Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers

• Christian Ganser,
• Gerhard Fritz-Popovski,
• Roland Morak,
• Parvin Sharifi,
• Benedetta Marmiroli,
• Barbara Sartori,
• Heinz Amenitsch,
• Thomas Griesser,
• Christian Teichert and
• Oskar Paris

Beilstein J. Nanotechnol. 2016, 7, 637–644, doi:10.3762/bjnano.7.56

• to obtain an estimate for the two half axes a and b of the elliptical pore cross-section, which are given in Figure 3b. Together with the lattice parameters A and B of the centered rectangular unit cell, the pore volume fraction (porosity) of the film can easily be calculated by . Moreover, the mean

Impact of ultrasonic dispersion on the photocatalytic activity of titania aggregates

• Hoai Nga Le,
• Frank Babick,
• Klaus Kühn,
• Minh Tan Nguyen,
• Michael Stintz and
• Gianaurelio Cuniberti

Beilstein J. Nanotechnol. 2015, 6, 2423–2430, doi:10.3762/bjnano.6.250

• illuminated batch reactors [6][7][8] and follow Langmuir–Hinshelwood kinetics [9][10]. This research has focused on the materials aspects such as the structural properties (e.g., surface area, particle size, crystal composition, porosity) [8][11] of pristine or modified photocatalysts [2][5][12]. However

Ultrastructural changes in methicillin-resistant Staphylococcus aureus induced by positively charged silver nanoparticles

• Dulce G. Romero-Urbina,
• Humberto H. Lara,
• J. Jesús Velázquez-Salazar,
• M. Josefina Arellano-Jiménez,
• Eduardo Larios,
• Anand Srinivasan,
• Jose L. Lopez-Ribot and
• Miguel José Yacamán

Beilstein J. Nanotechnol. 2015, 6, 2396–2405, doi:10.3762/bjnano.6.246

• cell wall becomes deformed and damaged is shown. Disruption of bacterial membranes induces pore and hole formation (Figure 9a,b) and also generates deformation of cell shape (Figure 7 and Figure 9a), damage of the PG layer, porosity of the cell membrane and consequent discharge of cytoplasmic (Figure

• interacting with their cell walls, resulting in imbalances and increased porosity of their cell membranes and a resultant loss of cytoplasmic content. EDS analyses showed the presence of smaller AgNPs in the cytoplasms of cells that possibly interacted with DNA material (Figure 10). Furthermore, the MIC

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method

• Mikalai V. Malashchonak,
• Alexander V. Mazanik,
• Olga V. Korolik,
• Еugene А. Streltsov and
• Anatoly I. Kulak

Beilstein J. Nanotechnol. 2015, 6, 2252–2262, doi:10.3762/bjnano.6.231

• of sample exposure in each solution and rinsing was 1 min. The cycle was repeated 5–300 times, then the sample was washed with distilled water and dried in air. SEM images were obtained with a LEO 1455 VP scanning electron microscope. The BET surface area and porosity measurements were performed

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

• fact that a longer anodization time does not increase the APT thickness is different from what is known for APA [24], where the oxide continues to grow at the expense of the underlying metal. In fact, in previous extensive studies, the nature of the porosity resulting in Ti from anodization was also

Selective porous gates made from colloidal silica nanoparticles

• Roberto Nisticò,
• Paola Avetta,
• Paola Calza,
• Debora Fabbri,
• Giuliana Magnacca and
• Dominique Scalarone

Beilstein J. Nanotechnol. 2015, 6, 2105–2112, doi:10.3762/bjnano.6.215

• characterized by a depth filter-like structure with internal porosity due to interparticle voids. Permeability and size-selectivity were studied by monitoring the diffusion of probe molecules under standard conditions and under the application of an external stimulus (i.e., electric field). Promising results

• covering the macroporous support. Figure 2B represents a schematic top-view of a single macropore (diameter of 5 μm) functionalized with nanoparticles in a depth-filter arrangement. The tortuous porosity is due to the tiny voids between the nanoparticles (interparticles voids) forming a disordered porous

• porosity of such depth-filter coatings, thicker samples of large weight were prepared by solvent-casting and N2 adsorption/desorption gas-volumetric analyses were performed. TEM measurements confirmed that the casting procedure adopted for this preparation provided a morphology similar to spin-coated

Effect of SiN_x diffusion barrier thickness on the structural properties and photocatalytic activity of TiO₂ films obtained by sol–gel dip coating and reactive magnetron sputtering

• Mohamed Nawfal Ghazzal,
• Eric Aubry,
• Nouari Chaoui and
• Didier Robert

Beilstein J. Nanotechnol. 2015, 6, 2039–2045, doi:10.3762/bjnano.6.207

• average grain size is not affected by the variation of the SiNx barrier thickness. From the fragmented cross-sections (Figure 2b), the film morphology appeared to be composed of distinguishable columns separated by boundaries, which corresponds to an intracolumnar porosity. Operating at pressures higher

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

• , this fabrication enables to set-up process parameters for facile control of nanofibrous mat properties such as surface area, fiber diameter, porosity, and thickness [15]. In the recent years, much effort has been devoted to modifying the electrospinning process, so coaxial, multi-jet, or side-by-side

• 86.6% for PLA nanofibers. These differences may have slightly influenced the release of incorporated molecules. However, the mercury porosimetry measurements were conducted in a vacuum. In an aqueous environment, in which the nanofibers are supposed to be used, the porosity may differ due to the

• diffuse through to reach the periphery of the material, which prolongs release times. The porosity of nanofibers did not appear to affect the release rate. A larger porosity may increase the volume of liquid that surrounds the fibers and consequently accelerate the release, but this effect was not

Metal hydrides: an innovative and challenging conversion reaction anode for lithium-ion batteries

• Luc Aymard,
• Yassine Oumellal and
• Jean-Pierre Bonnet

Beilstein J. Nanotechnol. 2015, 6, 1821–1839, doi:10.3762/bjnano.6.186

• ,z carbon is supposed to create of a porosity volume inside the electrode, corresponding to a volume increase due to matter transfer. This porous volume is then recovered during the lithium extraction and the total volume change of the electrode is then minimized. In addition, the carbon also acts as

• capacity retention of the MgH2–33.3% CMC–33.3% Ct,z/Li and MgH2–33.3% CMC-f–33.3% Ct,z/Li electrodes. Thus, porosity created by the polymers might explain the better volume accommodation of the electrode during lithium extraction. Further studies are needed for a better understanding of the nature of the

• shown promising results [62][63]. Thus, for solid-state hydrogen storage applications, very fast hydrogen absorption/desorption kinetics have been indeed confirmed for nanoscale Mg hydride (MgH2) confined into the porosity of different carbon hosts [64][65] or chemical matrices [66][67]. Very recently

Imaging of carbon nanomembranes with helium ion microscopy

• André Beyer,
• Henning Vieker,
• Robin Klett,
• Hanno Meyer zu Theenhausen,
• Polina Angelova and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2015, 6, 1712–1720, doi:10.3762/bjnano.6.175

• mechanical properties, such as elasticity and porosity, as well as the chemical composition of the resulting CNM. The freely suspended CNMs are made by transferring the cross-linked SAM from its substrate to a holey structure, such as a metal grid. The resulting CNM is approximately as thick as the original

The eNanoMapper database for nanomaterial safety information

• Nina Jeliazkova,
• Charalampos Chomenidis,
• Philip Doganis,
• Bengt Fadeel,
• Roland Grafström,
• Barry Hardy,
• Janna Hastings,
• Markus Hegi,
• Vedrin Jeliazkov,
• Nikolay Kochev,
• Pekka Kohonen,
• Cristian R. Munteanu,
• Haralambos Sarimveis,
• Bart Smeets,
• Pantelis Sopasakis,
• Georgia Tsiliki,
• David Vorgrimmler and
• Egon Willighagen

Beilstein J. Nanotechnol. 2015, 6, 1609–1634, doi:10.3762/bjnano.6.165

Thermal energy storage – overview and specific insight into nitrate salts for sensible and latent heat storage

• Nicole Pfleger,
• Thomas Bauer,
• Claudia Martin,
• Markus Eck and
• Antje Wörner

Beilstein J. Nanotechnol. 2015, 6, 1487–1497, doi:10.3762/bjnano.6.154

• properties (porosity, density, compressive strength, heat capacity) and the thermal stability up to 400 °C in an air atmosphere have been determined. Quartzite was chosen as the most suitable filler material because of its high thermal conductivity (caused by the high percentage of the mineral quartz) and

The Kirkendall effect and nanoscience: hollow nanospheres and nanotubes

• Abdel-Aziz El Mel,
• Ryusuke Nakamura and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 1348–1361, doi:10.3762/bjnano.6.139

• generated leading to the enlargement of the formed voids (Figure 2c) that will coalesce and form pores within the material. Until recently, the formation of pores in metal alloys as a consequence of the Kirkendall effect was considered as a serious problem in metallurgy. For example, porosity at the