Impact of air exposure and annealing on the chemical and electronic properties of the surface of SnO₂ nanolayers deposited by rheotaxial growth and vacuum oxidation

• Monika Kwoka and
• Maciej Krzywiecki

Beilstein J. Nanotechnol. 2017, 8, 514–521, doi:10.3762/bjnano.8.55

• structure of the layers as well as the post-exposition-related contamination. The studies are augmented with surface topography investigations using atomic force microscopy (AFM) in order to check the porosity of the resulting layer. Experimental The RGVO SnO2 nanolayers (20 nm, quartz microbalance

• nanolayers. The porosity of the nanolayers was confirmed by AFM investigation. The XPS data analysis performed for SnO2 nanolayers after UHV annealing suggested that most of the ambient–layer interactions during air exposure were based on physisorption or weak chemisorption. The air exposure process caused

The longstanding challenge of the nanocrystallization of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX)

• Florent Pessina and
• Denis Spitzer

Beilstein J. Nanotechnol. 2017, 8, 452–466, doi:10.3762/bjnano.8.49

• energetic matrix, GAP, with a maximum of 40 wt % RDX. They noticed a lower sensitivity than the physical mix. However, the claimed nanometer diameter is only deduced from the porosity without RDX and from X-ray diffraction (XRD) patterns which only give the mean coherence length. They also created NC-RDX-AP

Functionalized TiO₂ nanoparticles by single-step hydrothermal synthesis: the role of the silane coupling agents

• Antoine R. M. Dalod,
• Lars Henriksen,
• Tor Grande and
• Mari-Ann Einarsrud

Beilstein J. Nanotechnol. 2017, 8, 304–312, doi:10.3762/bjnano.8.33

• ). Since particle sizes from SEM and surface area are similar, porosity is associated with inter-particle volume of the agglomerates and can be directly correlated with the particle sizes [34]. Figure 4b displays the pore size distribution from desorption isotherms of TiO2 and in situ surface

Performance of natural-dye-sensitized solar cells by ZnO nanorod and nanowall enhanced photoelectrodes

• Saif Saadaoui,
• Mohamed Aziz Ben Youssef,
• Moufida Ben Karoui,
• Rached Gharbi,
• Emanuele Smecca,
• Vincenzina Strano,
• Salvo Mirabella,
• Alessandra Alberti and
• Rosaria A. Puglisi

Beilstein J. Nanotechnol. 2017, 8, 287–295, doi:10.3762/bjnano.8.31

• semiconductor thin layer film and the efficiency of the collected dye molecules [3][14][15]. The adsorption of the dye can be improved by various means, such as increasing the thickness and/or the porosity of the photoelectrode or by using organized structures, such as nanowalls or nanorods. The Voc can be

• reaction under sun illumination in the final DSSC [21]. Morphological results of the layers In order to estimate the capacity of the dye loading, scanning electron microscopy (SEM) analysis was carried out to study the porosity and the morphology of the layers prepared by the CBD technique [8][22]. Figure

• morphological change can be explained by aggregation of the dye and Zn2+ when the films were immersed in henna and mallow dye [24]. Figure 7a shows the morphology of the ZnO NWs annealed in FG. The NWs intersect at different angles, creating hollow spaces, acting to increase the porosity of the layer, which may

Optical and photocatalytic properties of TiO₂ nanoplumes

• Viviana Scuderi,
• Massimo Zimbone,
• Maria Miritello,
• Giuseppe Nicotra,
• Giuliana Impellizzeri and
• Vittorio Privitera

Beilstein J. Nanotechnol. 2017, 8, 190–195, doi:10.3762/bjnano.8.20

• statistical analysis showed that he roughness of the surface and the porosity of the structure increase with the etching time. In Figure 2a, a cross-sectional view STEM image of Ti (430-190) is reported. The sample shows the presence of a nanostructured material. The etching clearly expands from the surface

• of the Ti film to the bulk of the material, generating a nanostructured film with high porosity and roughness, that we called nanoplumes [21]. Nanoplumes (ca. 300 nm in thickness) show the presence of a residual Ti layer at the bottom (ca. 70 nm in thickness). Energy dispersive X-ray analyses

• the titanium layer undergoes multiple scattering in the nanoplume layer and it is partially re-absorbed. This effect is due to the high roughness and porosity of the material. Therefore, the measured spectrum shows a lower reflectivity value compared to the fitted spectrum in which the scattering

Sensitive detection of hydrocarbon gases using electrochemically Pd-modified ZnO chemiresistors

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Gennaro Cassano,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2017, 8, 82–90, doi:10.3762/bjnano.8.9

• similar gas sensing layers (e.g., Pd-sensitized ZnO nanobeads [48]). This is probably because of the lower film porosity. A high film porosity is necessary to obtain better results with this HCs gas sensing mechanism [49][50]. To evaluate and compare the cross-sensitivity of the unmodified and Pd-modified

Surface-enhanced Raman scattering of self-assembled thiol monolayers and supported lipid membranes on thin anodic porous alumina

• Marco Salerno,
• Amirreza Shayganpour,
• Barbara Salis and
• Silvia Dante

Beilstein J. Nanotechnol. 2017, 8, 74–81, doi:10.3762/bjnano.8.8

• , pore density and porosity is achieved by changing the anodization voltage during the fabrication and the etching parameters during the post-fabrication treatment [2]. It is widely recognized that the APA surface is biocompatible with practically all cell types and provides a means of controlling the

• carrier layer for local drug delivery [24], as a substrate for living cell cultures thanks to its controlled porosity [3][4][5][6][7], and for SERS [25]. However, since SERS is a surface-only effect, this sensitive detection will be limited to the top of the tAPA–Au substrates, i.e., to the bottom of the

• is different from the spectra collected on the Au–tAPA surface that are flat in the 2800–3000 cm−1 region. This indicates that the porosity of the substrate may influence the vesicle fusion process. This finding is still under further investigation. In Supporting Information File, Figure S1 the

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