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The study aimed at evaluation of the rheological properties of aqueous suspensions of SiC stabilized with either TMAH (tetramethyloammonium hydroxide) or NaOH in the amount of a given dispersant in the range of 0–1.0 wt% as calculated on the dry mass of SiC powder. The optimal amount of the dispersants was finally evaluated at 0.4–0.6 wt %, based on the results of rheological studies (flow curves and viscosity curves) and the sedimentation rate, which corresponded to the pH of the suspension within the range of 9.5–10.5. The amount of the dispersant here did not depend on the solid volume fraction in the suspension, but rather, according to the zeta potential measurement results, the pH range guaranteed the formation of a stable suspension. This effect allowed to propose a dispersant mechanism for stabilizing the suspension. The maximum amount of silicate anions formed, accordingly, in the pH range of 9.5–10.5 on the surface of SiC particles, which in turn could be able to adsorb Na+ or TMA+ cations and thus increase the thickness of the Stern layer, increasing electrostatic repulsion between the SiC particles and improving the stabilization of suspensions and their rheological properties. However, the increase in suspension pH deteriorated their stabilization – most likely due to the occurrence of polymerization of amorphous silica and the presence of additional cations in water increasing its ionic strength. These suggestions were confirmed by the results of XPS analysis of the chemical state of SiC particle surfaces.

International audience; The catalytic decomposition of N2O was studied over a series of calcined Mn(Fe)CoAl hydrotalcite-like compounds. The precursors were prepared by coprecipitation and characterized by XRD and TGA. The mixed metal oxides derived after calcination at 600 °C were characterized by XRD, N2 adsorption, H2-TPR and XPS. Moreover, in situ XAFS measurements over selected mixed metal oxides were performed. Such investigations under relevant reaction conditions are rare, while a comprehensive understanding of the involved active species may facilitate a knowledge-based catalyst optimization. The activity of the CoAlOx (Co/Al = 3/1, mol.%) catalyst varied depending on the loading of Mn or Fe (0.0575, 0.0821, 0.1150, 0.1725, 0.2300, mol.%). In the investigated series, Mn0.1725Co3AlOx reached the highest activity with T50 of about 305 and 376 °C under N2O/N2 and N2O,NO,O2/N2 feed, respectively. In situ X-ray absorption experiments over Mn0.1725Co3AlOx suggested that MnxCoyO4 spinels undergo reduction to CoO and MnO upon heating up to 600 °C in He. Under N2O/He conditions, initial reoxidation of cobalt species began at 350 °C. The lower activity obtained for Fe0.1725Co3AlOx is explained by the fact that the majority of Fe was not incorporated into the Co3O4 structure but instead formed less reactive iron oxide clusters.

Usage of CNTs as matrix modifiers during fabrication of CNFs from the electrospun polymer precursor is an interesting approach to obtain composite materials with a new set of properties. However, the progress in this field is hindered by the lack of consistency of the CNTs used in the studies and sometimes insufficient materials characterization. In this study, two types of CNTs were at first characterized to reveal their chemical composition and morphology (by TEM and XPS) and then used as matrix additives in the process of electrospinning. The outcome product was evaluated for morphology (SEM), chemical composition (XPS, FTIR), course of thermal transition (STA-FTIR) and level of structural arrangement (TEM combined with SAED) to answer the question how do CNTs interact with polymer matrix and how it impacts the process of thermal transition and properties of the as-received carbon nanofibers. Highly oxidized and short CNTs were found to increase the structural arrangement, catalyzing the thermal transition, while thin and long CNTs, with low amount of oxygen, entrap the nitrogen atoms, yielding nitrogen-doped CNFs that might be suggested as high-performance oxygen reduction reaction catalysts.

Amorphous silicon oxycarbide (SiOC) based materials are customarily called black glasses. In this work, hermetic layers on the steel substrate based on amorphous SiOC were obtained. The material was modified with cerium ions. Based on the literature, Ce as the modifier is responsible for i.e. enhancement of the corrosion resistance of materials and their antibacterial properties. SiCeOC coatings were produced via ceramization of the polymeric precursors synthesized by the sol-gel method and deposited on the metallic substrates with the use of the dip-coating technique. Numerous structural and microstructural studies were applied for the examination. It was proven that cerium is present in the material in the form of the inclusions and the material might be described as the SiOC/CeO2 composite. The surface properties such as roughness, wettability and surface free energy were also analyzed. Corrosion resistance tests were also conducted to establish the influence of the modification with cerium ions on the characteristics of the basal material. The results illustrated that a limited amount of the modifier enhanced corrosion resistance of black glasses without changes in their structure. However, the modification does not promote Ce ion release and the antibacterial tests showed the materials do not possess antibacterial properties.

Physicochemical, electrochemical and biological performance of 4 types of all-carbon nanotube layers was studied. Higher oxidation state of carbon was responsible for micro-scaled uniformity of the layers and excellent electrical conductivity, while nitrogen containing functional groups yielded materials with anisotropy similar to natural tissues and reduced work function. All materials were cytocompatible with mammalian fibroblasts (viability80%, cytotoxicity3% at day 7) and human dermal fibroblast (viability of cells70% at day 1), while reducing bacterial and cancer cells proliferation without adding any drug. After 8 h culture, a ~50% depletion in the number of Gram-positive bacteria was observed on materials with lower work function, while Gram-negative bacteria were more sensitive towards carbon coordination number and presence of nitrogen atoms (cell depletion of up to 48% on amidized carbon nanotubes). After 1-day culture,80% reduction in the melanoma cells number, connected with enhanced production of reactive oxygen species (ROS) was observed. All-carbon nanotube layers decreased bacteria and cancer cell functions without negatively influencing mammalian cells nor using drugs and we believe that this can be explained by various sensitivity of the tested cells towards exogenous ROS overproduction. As the concerns over implant-related infections as well as rates of antibiotic-resistant bacteria and chemotherapeutic-resistant cancer cells are growing, such materials should pave the way for a wide range of biomedical applications.

The quality and relevance of nanosafety studies constitute major challenges to ensure their key role as a supporting tool in sustainable innovation, and subsequent competitive economic advantage. However, the number of apparently contradictory and inconclusive research results has increased in the past few years, indicating the need to introduce harmonized protocols and good practices in the nanosafety research community. Therefore, we aimed to evaluate if best-practice training and inter-laboratory comparison (ILC) of performance of the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay for the cytotoxicity assessment of nanomaterials among 15 European laboratories can improve quality in nanosafety testing. We used two well-described model nanoparticles, 40-nm carboxylated polystyrene (PS-COOH) and 50-nm amino-modified polystyrene (PS-NH2). We followed a tiered approach using well-developed standard operating procedures (SOPs) and sharing the same cells, serum and nanoparticles. We started with determination of the cell growth rate (tier 1), followed by a method transfer phase, in which all laboratories performed the first ILC on the MTS assay (tier 2). Based on the outcome of tier 2 and a survey of laboratory practices, specific training was organized, and the MTS assay SOP was refined. This led to largely improved intra- and inter-laboratory reproducibility in tier 3. In addition, we confirmed that PS-COOH and PS-NH2 are suitable negative and positive control nanoparticles, respectively, to evaluate impact of nanomaterials on cell viability using the MTS assay. Overall, we have demonstrated that the tiered process followed here, with the use of SOPs and representative control nanomaterials, is necessary and makes it possible to achieve good inter-laboratory reproducibility, and therefore high-quality nanotoxicological data. European Commission | Ref. EC FP7 QualityNano (INFRA-2010-1.1.31- 262163) Fonds National de la Recherche of Luxembourg | Ref. NANION (FNR / 12 / SR / 4009651) Direction générale opérationnelle de l’Economie, de l’Emploi et de la Recherche (Walloon, Belgium) | Ref. ‘QNano’ (2011-14) n. 1117448 Norwegian Research Council | Ref. NorNANoREG 239199/070

The researches presented in this work were devoted to electrochemico-chemical regeneration of exhausted electrode made of expanded graphite (EG). The aimed process was conducted by electrochemical treatment and ozone flow performed together in wet environment. EG was covered with insoluble products of incomplete oxidation of phenol formed during cyclic voltammetry measurement. The same electrochemical technique was applied for evaluation of regeneration efficiency. To understand the process of EG regeneration, the electrode was characterized by calculating of BET surface, FTIR and XPS analysis. Moreover, SEM images of the investigated samples were also done. Obtained results have showed the success of regeneration treatment, which led to significant enhancement of electrode activity compared to original EG. The present work also revealed that the mechanism of phenol electrooxidation is changed after the regeneration treatment of electrode material. This effect is probably caused by the modification of chemical composition of EG surface due to its interactions with OH radicals intensively generated during the process of regeneration.

Titanium dioxide in the form of anatase is known to be a good photocatalyser but catalytic properties strongly depend on TiO2 grain size, morphology and surface area of thin film. The aim of this study was to evaluate influence of carbon nanotube additive on photocatalitic properties of TiO2.Titanium dioxide/multiwalled carbon nanotubes (MWCNT) nanocomposites were prepared by sol-gel method in the form of a thin layer on glass substrates. Samples were characterized by X-ray diffraction (XRD) and Grazing Incidence Diffraction (GID), Raman, FTIR and UV-VIS spectroscopy, as well as scanning electron microscopy (SEM). The photocatalytic activity of prepared films was evaluated by the detection of changes in the UV-VIS spectra after the discoloration of Reactive Black V pigment - water solution. It was found that the crystalline TiO2 is composed of anatase phase only. Presence of MWCNTs in the composite increases the size of TiO2 particles. Additive of nanotubes into the TiO2 resulted in an increase in photocatalytic activity in both the UV and visible range by 10 and 50% respectively compare to undoped TiO2. Furthermore, carbon nanotubes lead to better dye adsorption on the surface. Additionally significant reduction in the contact angle, approximately 50% (compare to pure TiO2) was also observed. The obtained results suggest that the TiO2/carbon nanotubes composite material can be activated by light from visible range.

XRD, BET, H2-TPR, UV–vis-DRS, XPS and XAFS were used to characterize a series of Ag and/or Cu – Ag (1–5%), Cu (10–15%) or Ag-Cu (1–1, 1–10, 1.5–10, 5–5% of metal) – supported on γ-Al2O3. Correlation between physicochemical properties, catalytic activity and selectivity in NH3-SCO were thoroughly investigated. Silver species mainly in the form of Ag2O on the Ag/Al2O3 catalysts led to enhanced activity together with drop in N2 selectivity with increasing silver loading up to 5%. A mixture of CuO and CuAl2O4 formed on the Cu/Al2O3 catalysts. Easily reducible highly dispersed CuOx promoted the activity of the catalysts, while bulk CuOx and CuAl2O4 decreased N2 selectivity up to 500 °C. The activity of all Cu-containing materials was inferior to Ag-containing ones. Thus, the gap between the high conversion temperature over Cu/Al2O3 and low N2 selectivity over Ag/Al2O3 was bridged by applying the Ag-Cu/Al2O3 catalysts, with the optimum loading of 1.5 and 10 wt.% for silver and copper, respectively. NH3-TPD, NH3-TPSR and in situ FTIR were used to determine the in situ selective catalytic reduction (i-SCR) mechanism over 1.5% Ag/Al2O3, 10% Cu/Al2O3 and 1.5% Ag-10% Cu/Al2O3 respectively. The i-SCR mechanism involved the partial oxidation of NH3 into NOx species, along with adsorbed NOx species interacting with adsorbed ammonia (NHx species) and being reduced to reaction products.

The work was focused on the spectroscopic examination of zirconia-based layers deposited on metallic substrates. Metallic biomaterials belong to the group of well-known and most widely applied materials in medicine. They might be characterized by the easiness of formation and good mechanical properties. However, the surface properties of the material need to be strictly controlled to prevent corrosion processes and ensure biocompatibility. One of the modifications leading to improvement of the properties important in terms of considering the material for biomedical applications was the fabrication of ceramic layers on the surface. Presented zirconia-based layers doped with calcium and hydroxyapatite were obtained using the sol-gel method and deposited on the metallic (titanium and steel) surface with the use of dip-coating technique and electrophoretic deposition (EPD) method. Obtained layers were examined with multiple spectroscopic and microscopic methods such as Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Also the surface properties – wettability and surface free energy (SFE) – were measured. Bioactivity of the obtained layers was evaluated by the in vitro test in simulated body fluid (SBF) - the so-called Kokubo test.

N2O is a potent greenhouse gas released among others in nitric and adipic acid production as well as from stationary and mobile combustion sources. A catalytic decomposition is highly attractive but requires catalysts active over a broad temperature range and in the presence of inhibiting compounds such as NO and O2. Ag-doped Co-(Mg)-Al-Ox mixed metal oxides obtained by the coprecipitation of metal nitrate precursors followed by calcination were evaluated as potential catalysts for N2O decomposition (deN2O) also in the presence of NO and/or O2. Ag integration during synthesis proved to be essential for superior catalytic activity. The catalyst with the optimum composition, AgCo3Al-Ox (Co/Al=3:1 mol %, 1.0 wt % Ag), achieved full N2O conversion at 350 and 450 °C under N2O/N2 and N2O/NO/O2/N2 conditions, respectively. Catalyst characterization, with a focus on H2 temperature-programmed reduction and X-ray photoelectron spectroscopy, evidenced that abundant Ag0 on the surface of (1.0–2.8 wt %)AgCo3Al-Ox enhanced the reduction of cobalt spinels to enable the superior catalytic performance.

Ag-, Ce- and Ga-promoted Cu–Mg–Al hydrotalcite derived mixed metal oxides were obtained by standard coprecipitation, followed by calcination. The obtained Ag(Ce, Ga)–Cu–Mg–Al–O x mixed metal oxides were characterized with respect to their crystalline structure (XRD, TEM), texture (BET), surface acidity (NH 3 -TPD), redox properties (H 2 -TPR), chemical surface composition (XPS), and tested in the selective catalytic oxidation of ammonia into nitrogen and water vapour (NH 3 -SCO). The loading of Ag y -, Ce y -, or Ga y –Cu 5 –Mg 66− y –Al 29 ( y = 0–1) had a clear effect on the catalytic performances. For materials with low metal loadings ( y ≤ 0.25), the redox properties determined the catalytic performances in NH 3 -SCO. The formation of easily reducible CuO x played a crucial role for enhanced catalytic activity at lower temperatures, with a drop in the selectivity to N 2 at higher temperatures. Higher metal loading ( y ≥ 0.5) led to the formation of surface and bulk copper oxide species, and other aggregated metal oxide phases, which enhanced the catalytic activity for Ag–Cu–Mg–Al–O x , and diminished activity for Ce(Ga)–Cu–Mg–Al–O x .

The paper studies an influence of Ga2O3, PbO and BaF2 on the thermal stability of tellurite glass and their properties: thermal expansion coefficient, transmittance and refractive index. Three series of gallium-tellurite glass were prepared: I – (100 − x)TeO2·xGa2O3 where x = 5, 10, 15 and 25 mol%, II – (85 − x)TeO2·15Ga2O3·xBaF2 where x = 1, 3, 6, 11 mol%, III – (90 − x)TeO2·10Ga2O3·xPbO where x = 0, 5, 10 mol%. It was confirmed that stable gallium-tellurite glass can be produced without applying super-cooling methods in the range 5–15 mol% Ga2O3. Ga2O3 acts only as a stabilizer of the TeO2 glassy network when its content not exceed 15 mol%. As shown this effect is connected with the change in crystallization ability of orthorhombic and tetragonal forms of TeO2. It was found that the latter is preferable when Ga2O3 content increases. The increase of the Ga2O3 content over 20 mol% induces its spontaneous crystallization. Admixture of BaF2 and PbO to the Te2O-Ga2O3 glass diminishes a tendency to the glass crystallization. Tellurite glasses with Ga2O3, PbO and BaF2 show good transmittance in the VIS, NIR and MIR up to 5.5 μm. BaF2 and PbO, unlike Ga2O3, decrease the thermal expansion coefficient of tellurite glass. The change in the refractive index due to the admixtures was presented.

Coating the material of choice with a layer of well-adhered carbon nanotubes is a subject of interest in many fields of materials science and industry. Electrophoretic deposition is one of the methods to handle this challenging task. In this process, careful designing of the deposition parameters is crucial in obtaining the product of strictly desired properties. This study was aimed to identify the influence of the diluent on the physicochemical ad electrochemical qualities of the final product. By analyzing the properties of the suspensions being used, we were able to hypothesize on the mechanisms of carbon nanotubes—liquid interactions and their outcome on the thickness, homogeneity, chemical and structural composition and electrical conductivity of the metal substrate covered with a layer of carbon nanotubes. We obtained a materials, composed of metal and a layer of CNTs, with conductivity that is superior to an unmodified metal. This types of materials may find numerous applications in fabrication of novel electronic devices, including the implantable electrodes for biomedicine—as reported in our previous studies, these types of coating are biocompatible.

Materials based on CoSb3 are ranked among thermoelectrics with the highest conversion rate, however in service they tend to rapidly lose the useful properties as a result of oxidation or sublimation. Glass coatings were designed in this work to protect CoSb3 against degradation in air at elevated temperatures. The coatings were based on borosilicate glass with a high content of titania. Their chemical composition was tailored to match the coefficient of thermal expansion (CTE) of the substrate (9.2 · 10−6 K−1) and to secure thermal stability and low softening point of glass. The coatings deposited by a simple dipping technique were fired in the temperature range 700–740 °C. Evaluation of these coatings was based on accelerated oxidation tests at 600 °C for 20 h. The micro- and nanostructure of the CoSb3/glass coating interface were examined by means of advanced electron microscopy. The coating appeared to have good adherence and to effectively protect the thermoelectric substrate against antimony loss and oxidation up to 600 °C. Keywords: Thermoelectrics, CoSb3, Glass coating, Oxidation

The present work demonstrates a simple and low-cost method to produce bulk quantities of graphene material through the thermal treatment of graphite oxide (GO). GO of a high oxidation degree was synthesized by electrochemical overoxidation of natural graphite in 11 M H2SO4 using linear sweep voltammetry (LSV) technique. The thus synthesized GO was thermally exfoliated-reduced at 500 °C in air, giving the final product – thermally reduced graphite oxide (TRGO). It should be emphasized that the process of TRGO formation from electrochemically obtained GO is for the first time described in the present work. Due to shock treatment, the BET specific surface area of TRGO increased from 4 to 455 m2 g−1. Additionally, a decrease in the concentration of oxygen functionalities was also observed. Thermal stability of electrochemically synthesized GO was investigated by thermogravimetric analysis (TGA). In order to characterize the synthesized TRGO, investigations by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were performed.

Paulina Kazimierczak,1 Aleksandra Benko,2 Marek Nocun,2 Agata Przekora11Department of Biochemistry and Biotechnology, Medical University of Lublin, Lublin, Poland; 2Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Krakow, PolandCorrespondence: Agata PrzekoraDepartment of Biochemistry and Biotechnology, Medical University of Lublin, Chodzki 1 Street, Lublin 20-093, PolandTel +48 81 448 7026Fax +48 81 448 7020Email agata.przekora@umlub.plBackground: Nanocomposites produced by reinforcement of polysaccharide matrix with nanoparticles are widely used in engineering of biomaterials. However, clinical applications of developed novel biomaterials are often limited due to their poor biocompatibility.Purpose: The aim of this work was to comprehensively assess biocompatibility of highly macroporous chitosan/agarose/nanohydroxyapatite bone scaffolds produced by a novel method combining freeze-drying with a foaming agent. Within these studies, blood plasma protein adsorption, osteoblast (MC3T3-E1 Subclone 4 and hFOB 1.19) adhesion and proliferation, and osteogenic differentiation of mesenchymal stem cells derived from bone marrow and adipose tissue were determined. The obtained results were also correlated with materials’ surface chemistry and wettability to explain the observed protein and cellular response.Results: Obtained results clearly showed that the developed nanocomposite scaffolds were characterized by high biocompatibility and osteoconductivity. Importantly, the scaffolds also revealed osteoinductive properties since they have the ability to induce osteogenic differentiation (Runx2 synthesis) in undifferentiated mesenchymal stem cells. The surface of biomaterials is extremely hydrophilic, prone to protein adsorption with the highest affinity toward fibronectin binding, which allows for good osteoblast adhesion, spreading, and proliferation.Conclusion: Produced by a novel method, macroporous nanocomposite biomaterials have great potential to be used in regenerative medicine for acceleration of the bone healing process.Keywords: XPS, wettability, protein adsorption, osteogenic differentiation, cell proliferation, cryogel

This work demonstrates the adsorption capacity of carbon micro- (CF) and nanofibrous (CNF) adsorbents differing in specific surface area, fiber diameter and open porosity in the removal of NaCl from water. The effect of the adsorption conditions, i.e. contact time, initial salt concentration, and oxidative surface treatment on the adsorption kinetics and equilibrium salt uptake capacity was investigated. Adsorption experiments were carried out by batch-mode experiment at room temperature. The study showed that activated CNF exhibit high adsorption capacity for NaCl, namely 827.5 mgNaCl/gCNF, and this value is over 40 times higher than that of activated carbon and exceeds the values reported for CNT and GO. The adsorption kinetics followed the pseudo-second-order kinetic model and was largely controlled by the intramolecular diffusion rate. The equilibrium data showed a good correlation with the Langmuir and Freundlich isotherms, which supported the complex interaction of salt with the carbon surface. It was shown that salt ions can be attached to the fibrous surface both by ion-exchange mechanisms and electrostatic interactions. The carbon fibrous adsorbents present a new approach to water desalination through the mechanism of adsorption and continuous crystallization, and may be used for the elaboration of new type membranes for water purification and desalination.

The main objective of this paper is to attempt to determine the structure of free carbon phase in SiOC glasses derived from ladder-like silsesquioxane precursors. The samples were fired in argon flowing atmosphere, in a wide temperature range (200–800° C). Conducted XRD, Raman, MIR spectroscopy research allowed to determine the structure of obtained materials. Combined XPS and Raman studies enabled to establishing the point of formation of free carbon in silicon oxycarbide matrix. Two most popular concepts were confronted with Raman and XPS results of free carbon phase in studied materials. This allowed to conclude that for temperatures below 800 °C carbon is present in a form of graphite domains inside glassy matrix.

Structural changes accompanying stabilization and carbonization processes of the two types of polyacrylonitrile (PAN) nanofiber precursors (pure PAN and PAN with carbon nanotubes) were studied using infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The fibrous membranes were preliminary stabilized in air followed by the two-step carbonization process under nitrogen atmosphere. IR absorption spectra showed that the introduction of a small amount of functionalized multiwall carbon nanotubes (MWCNT) into the PAN precursor has a significant impact on its stabilization process. Raman spectroscopy study showed that the structure of carbon nanofibers containing CNT is distinctly more ordered in comparison to pure carbon nanofibers. Based on the XPS analysis the concentration of heteroatoms and the type and amount of functional groups on the surfaces of both types of nanofibers were determined. The results indicate a high potential of functionalized MWCNT as a pyrolysis modifier of polymer precursor leading to the formation of carbon nanofibers with controlled structure and defined chemical state of the surface.

Oxide phases formed at early oxidation stages on unmodified and yttrium-implanted β-NiAl intermetallic compound were studied with the aid of photoluminescence spectroscopy in scales developed at 1473 K for oxidation periods of up to 4 h. Two-stage-oxidation exposures with18O2-tracer were applied. The PLS method was also used to assess the residual stresses in α-Al2O3scale at consecutive stages of its development. It was found that scale formation occurs in a very local way, related to inhomogeneous distribution of Cr in substrate: sometimes distances as short as 10–15 μm were sufficient to observe entirely different phases in the scale. In general, implanted yttrium was found to retard the formation of a stable and protective layer of α-Al2O3. Oxidation for 4 h was necessary for no transient aluminum oxides (mostly θ and/or δ) to be detected, while on non-implanted material they were not found after only 26 min exposure. Only compressive stresses were found in α-alumina scales. They were rather high, reaching even 5 GPa. However, their dependence on the regions in the scale and the scale evolution stage was observed. The results indicate that patches frequently observed in scales on β-NiAl are regions where the phase transformation of transient aluminas to the α phase occurs preferentially. Ridges, which fill the transformation-related cracks, consisted only of α-Al2O3. Combination of these results with those obtained using SIMS distribution analyses of oxygen isotopes as well as with SEM/EDX, enabled very precise conclusions to be inferred concerning the scale growth mechanism. In particular, the local nature of the scale development can be described in more detail. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

The use of methanol as an alternative fuel for gasoline or diesel engines increases the unregulated CH3OH emission. γ-Al2O3 modified with Cu, Mn, Ce, K, Ag, Cu–Mn, Cu–Ce, Cu–Ag or Cu–K (0.5, 1.0, 0.5:0.5, 1.0:1.0 wt% of metal) catalysed the process of methanol incineration. The highest activity reached samples containing 1.0 wt% of silver. Dispersed Ag+ species on Al2O3 served as active species for selective oxidation of CH3OH to CO2 over both Ag/Al2O3 and Cu–Ag/Al2O3. Additionally, the XPS and EPR results revealed the AgO interface between the Ag2O and CuO in the Cu–Ag system.

Very early stages of development of the oxide scale formed in air at 1150° on unmodified and containing varying amounts of Pt (5, 10 and 15 at.%) β-NiAl intermetallic compound were studied. The scale morphology was observed using scanning electron microscopy, while photoluminescence spectroscopy was applied to determine its phase composition with spatial resolution down to 1 μm. It was found that the scales were non-uniform in terms of their morphology and, to a lesser extent, of their phase composition. Pt additions resulted in earlier development of the α-Al2O3 oxide, which, based also on recently reported literature experimental and modelling results, may be attributed to the increased rate of the scale evolution. The possible direct effect of Pt on the phase transformation of unstable aluminium oxides into α-Al2O3 still needs to be verified as the complementary or alternative explanation. © 2017, Springer Science+Business Media New York.

Early oxidation of unmodified and yttrium-implanted or chromium-implanted β-NiAl intermetallic compound at 1473 K was studied using a combination of two-stage-oxidation exposure with 18 O 2 as a tracer, SIMS elemental distribution analysis (depth profiling and imaging modes) and photoluminescence spectroscopy analysis of the scale phase composition. It was found that phase transformation of transient aluminium oxides, represented by 6- Al 2 O 3 into stable and protective α-Al 2 O 3 occurs locally and is affected by implanted additions: Yttrium retarded while chromium appeared to accelerate it. Typical patch- and/or web-like scale morphology of the growing scales was observed.

This paper reports on the comparison of scale development on unmodified β-NiAl which contains volume and surface additions of yttrium. This reactive element was incorporated using conventional alloying (0.05 or 0.1 wt%) and ion implantation. The materials containing alloyed yttrium were also implanted with yttrium to study the combined influence of volume and surface additions. A two-stage oxidation approach was applied with the use of 18O 2 as a tracer. The reaction temperature was 1100°C and the samples were oxidised for up to 64 h. The scale growth mechanism was followed with the aid of in-depth distributions of the oxygen isotopes across the scale using secondary ion mass spectrometry, the surface morphology of the scales was observed using scanning electron microscopy, while their phase composition was determined using photoluminescence spectroscopy. Similar stages of the scale evolution were observed for the growing scales. Initially the oxide layer consisted of transient oxides, and at its surface more or less developed blade-like surface grains were observed. Subsequently, phase-transformation- related cracks and round patches appeared, and finally ridges which successively covered the outer surface of the scale and constituted the outer layer of a duplex scale developed. The mechanism of scale growth was a mixed outward and inward, and the relative contribution of both mechanisms varied depending on the analysed scale region and on the oxidation stage. The cracks and patches were regions where the transient aluminas were preferentially transformed into α-Al 2O 3. The ridges formed in cracks essentially consisted of α-Al 2O 3. For the initial stages of oxidation, the transient aluminas and α-Al 2O 3 co-existed in the scales, while subsequently the latter prevailed and finally, became the only phase found in the oxide layers. The evolution rate of the scale was affected by alloyed and implanted yttrium additions: the former exhibited minor and content-dependent effect while the latter significantly retarded it.

The aim of the study was to fabricate and extensively characterize a layer of carbon nanotubes deposited on the surface of titanium, in order to prove that, by selecting proper type of carbon nanotubes and altering different parameters of the electrophoretic deposition process, we are able to obtain products having a different influence on cells—either favouring or inhibiting their survival. In the study, a novel mixture of solvents was used to suspend as-received tubes and then applied in the electrophoretic deposition. High charging capability and high yield of the obtained deposits are promising results when considering up-scaling the process. The surface of the obtained multi-walled carbon nanotubes-coated titanium samples was characterized using SEM, AFM, XPS and Raman microspectroscopy. The carbon nanotube layer showed nanorough topography and was formed of randomly and loosely distributed tubes, and XPS study revealed that there was a significant amount of C–O bonds. These properties were found to be favourable to osteoblast survival, spreading and growth.

Some reports indicate that the silver released from dermally applied products containing silver nanoparticles (AgNP) (e.g. wound dressings or cosmetics) can penetrate the skin, particularly if damaged. AgNP were also shown to have cytotoxic and genotoxic activity. In the present study percutaneous absorption of AgNP of two different nominal sizes (Ag15 nm or Ag45 nm by STEM) and surface modification, i.e. citrate or PEG stabilized nanoparticles, in combination with cosmetic ingredients, i.e. aluminum chloride (AlCl 3 ), methyl paraben (MPB), or di-n-butyl phthalate (DBPH) was assessed using in vitro model based on dermatomed pig skin. The inductively coupled plasma mass spectrometry (ICP-MS) measurements after 24 h in receptor fluid indicated low, but detectable silver absorption and no statistically significant differences in the penetration between the 4 types of AgNP studied at 47, 470 or 750 μg/ml. Similarly, no significant differences were observed for silver penetration when the AgNP were used in combinations with AlCl 3 (500 μM), MPB (1250 μM) or DBPH (35 μM). The measured highest amount of Ag that penetrated was 0.45 ng/cm 2 (0.365–0.974 ng/cm 2 ) for PEG stabilized Ag15 nm + MPB.