Small Oxide Particles Research Articles

High performance of direct methane-fuelled solid oxide fuel cell with samarium modified nickel-based anode

Natural gas is one of the most attractive fuels for solid oxide fuel cell (SOFC), while the anode activity for methane fuel has a great influence on the performance and stability of SOFC. Samarium is a good catalyst promoter for methane reforming. In this work, samarium is used to modify nickel catalyst, which results in small nickel oxide particles. The SmNi-YSZ (yttria-stabilized zirconia) anode has smaller particles and better interfacial contact between nickel and YSZ compared with conventional Ni-YSZ anode. The fine structure of SmNi-YSZ anode results in high activity for electrochemical oxidation of hydrogen and low polarization resistance of the cell. The performance of SmNi-YSZ anode cell with humidified methane as fuel is greatly improved, which is similar to that with hydrogen as fuel. The maximum power densities of SmNi-YSZ anode cell are 1.56 W cm−2 for humidified hydrogen fuel and 1.54 W cm−2 for humidified methane fuel at 800 °C. The maximum power density is increased by 221% when samarium is used to modify Ni-YSZ anode for humidified methane fuel at 650 °C. High cell performance results in good stability of SmNi-YSZ anode cell and the cell runs stably for more than 600 min for humidified methane fuel.

Diffusion of poly (l-lactide) in activated metal organic frameworks; crystallization evidenced by ssNMR and subsequent shape memory effects

Shape-memory polymers are a class of materials that show dual or multi-shape competence. Here a solvent casting method was used to prepare composite films from Cu-BTC crystals in poly (l-lactide) (PLLA) to induce crystallization leading to a marked shape memory effect (SME). Extensive physico-chemical characterizations including solid-state NMR indicated that Cu-BTC triggered the crystallization of PLLA for ensuring the entropy needed for the shape memory behavior. The diffusion of polymeric chains inside pores of activated Cu-BTCs ensured interactions which increases the crystallinity as both simulation and experimental results show. Moreover, the segregation of Cu-BTC crystallites to small copper oxide particles due to the activation increases the volume of the crystalline region observed by microscopic images. We compared the identical features of composite prepared in the same method in where small molecule was encapsulated inside Cu-BTC with PLLA/5 wt% Cu-BTC; we were able to show that having the sharp transition of elastic to rubbery state in the vicinity of cold crystallization temperature in PLLA/5 wt% Cu-BTC provides Cu-BTC crystallites to act as netpoints. Moreover, the reinforcement accompanied by increased toughness demonstrates the combination of improved mechanical properties as well as SME of polymers which rarely have attained.

Strengthening of ods silver wires

The present work is part of an experimental program in which the mechanical behavior and the evolution of microstructure and texture of different industrially manufactured oxide-dispersion strengthened silver alloys upon different processing steps like hot-extrusion, cold-working and further annealing have been investigated. The investigations reveal that the incoherent oxide particles strongly influence the evolution of microstructure and texture during processing and consequently the deformation behavior at room temperature. Small oxide particles cause a high strengthening of the material but only a small change of the microstructure and texture. Increasing the oxide particle size subsequently reduces the strength and changes the original microstructure and texture in a more pronounced way. The yield strength at room temperature can be explained with a linear superposition of the Orowan stress for bypassing of oxide particles by dislocations and grain boundary strengthening according to Hall-Petch. The impact of texture of the materials on the yield strength is accounted for.

Fabrication of Highly Filled Composites with an Innovative Miniaturized Spouted Bed

In nature bio-composites such as nacre show remarkable mechanical properties due to their complex hierarchical structure and high-volume fraction of its hard component. These composites are highly interesting for structural applications in different branches of industries for mechanical engineering and process technology. The aim of this work was to provide a scalable method for the production of highly filled composites by mimicking the structure of bio-composites. Therefore, composites from iron oxide (Fe2O3) and SBC-polymer (styrene-butadiene block copolymer) were fabricated by using a miniaturized spouted bed with an innovative fluidization gap design. Small iron oxide particles (25–45 μm) were fluidized in the spouted bed and coated with a polymer solution via a bottom spray nozzle. Afterwards the coated granules were hot-pressed and the mechanical properties of the obtained composites were tested. By this method composites with a bending strength of up to 6 MPa were fabricated. Although the mechanical properties of these artificial composites are still lower than those of the natural role models, it was shown that the spouted bed is a suitable technique for the fabrication of highly filled composites. For further optimization of the mechanical properties more complex and tailor-made starting materials will be used in following studies.

Toxicity and Functional Impairment in Human Adipose Tissue-Derived Stromal Cells (hASCs) Following Long-Term Exposure to Very Small Iron Oxide Particles (VSOPs).

Magnetic nanoparticles (NPs), such as very small iron oxide NPs (VSOPs) can be used for targeted drug delivery, cancer treatment or tissue engineering. Another important field of application is the labelling of mesenchymal stem cells to allow in vivo tracking and visualization of transplanted cells using magnetic resonance imaging (MRI). For these NPs, however, various toxic effects, as well as functional impairment of the exposed cells, are described. The present study evaluates the influence of VSOPs on the multilineage differentiation ability and cytokine secretion of human adipose tissue derived stromal cells (hASCs) after long-term exposure. Human ASCs were labelled with VSOPs, and the efficacy of the labelling was documented over 4 weeks in vitro cultivation of the labelled cells. Unlabelled hASCs served as negative controls. Four weeks after labelling, adipogenic and osteogenic differentiation was histologically evaluated and quantified by polymerase chain reaction (PCR). Changes in gene expression of IL-6, IL-8, VEGF and caspase 3 were determined over 4 weeks. Four weeks after the labelling procedure, labelled and unlabelled hASCs did not differ in the gene expression of IL-6, IL-8, VEGF and caspase 3. Furthermore, the labelling procedure had no influence on the multidifferentiation ability of hASC. The percentage of labelled cells decreased during in vitro expansion over 4 weeks. Labelling with VSOPs and long-term intracellular disposition probably have no influence on the physiological functions of hASCs. This could be important for the future in vivo use of iron oxide NPs.

TEM analysis of whiskers formation over tin-plated films

Whiskers grown from tin films plated on brass plates were examined by transmission electron microscopy. After plating, the tin film, which was held at 323 K for five days, was composed of an amorphous phase and spherical β-Sn particles. The amorphous phase formed immediately upon plating, while after being maintained at this temperature, the amorphous phase crystallized to form β-Sn particles. After holding for 14 days, many rod-like whiskers with diameters of 0.1–0.2 μm and lengths of 1 μm were observed. The whiskers comprised β-Sn single crystals covered with SnO2 crystals several nanometers in size. It appeared that the growth of the oxide did not inhibit whisker growth. The reason is that the small oxide particles slide and rotate relative to each other, and the oxide covering β-Sn deforms during whisker growth. If the surface layer cannot be deformed, the whisker will continue to grow, maintaining the core shell structure through destruction and regeneration of the oxide coating.

Annealing Effects on the Microstructure and Thermomechanical Properties of New-Generation ODS Alloys

Recently, the use of high temperature materials are became more common in different types of engineering activities. The new generation of Oxide dispersion strengthened alloys (ODS) consist of Fe-Al matrix with small oxide particles dispersed within it, was generated by the authors to keep their mechanical properties at elevated temperatures. The new ODS prepared by means of mechanical alloying and hot consolidation. The preliminary tests results shows a better oxidation resistant, creep and Ultimate Tensile Strength (UTS) compare to similar materials. To go more inside in thermomechanical and microstructural properties, a series of different test were performed on different variant of ODS which manufactured by the authors. The results show that the annealing time and temperature has a significant influence on these properties while almost total recrystallization of grains and subgrains were observed during the investigation.

The removal of zinc ions from their aqueous solutions by Cr2O3 nanoparticles synthesized via the UV-irradiation method

A modification of an UV-irradiation method is used to synthesis of Cr2O3 nanoparticles. It is a simple and easy way to produce small particles of chromium oxide at a range of 2 – 30 nm according to the transmission electron microscopy (TEM) and X-ray diffraction (XRD) characterizations. In this study, the synthesized nanoparticles are used as an adsorbent for zinc ions from their aqueous solutions under effect of different temperatures 15, 25, 35, 45 and 55 oC. The adsorption process of zinc ions is endothermic (ΔH is 10.33 kJ/mol ) and its data fitted well with the Freundlich isotherm model (R2=0.9601). The data of adsorption show non-spontaneously in nature when the thermodynamic parameter ΔG is positive (1.515 kJ/mol). However, the ΔG changes to a negative value with the temperature rising and the process begins spontaneously because the adsorption capacity increases with increase in temperature.

Microstructure, tensile and creep properties of an austenitic ODS 316L steel

ODS 316L, an austenitic grade of oxide-dispersion-strengthened (ODS) steel, was fabricated by mechanical alloying, hot isostatic pressing and forging. A broad characterisation study was conducted, including High-Resolution Transmission Electron Microscopy (HRTEM) to investigate the microstructure and the interface between oxide particles and the 316L matrix. Mechanical properties at room and elevated temperature were determined by means of tensile and creep tests. Data from the room temperature and high temperature tensile tests were compared with those from conventional 316L. Creep data were used to assess the performance of the ODS 316L against standard assessment codes and in comparison with conventional 316L. Higher mechanical strength was found for the ODS 316L, in comparison to conventional 316L, at room temperature. UTS at high temperature was lower for the ODS 316L, but its yield strength was twice that of 316L. It was found that, although compliant with the Design and Construction Rules for mechanical components of nuclear installations (RCC MR) [1] code for the creep test conditions imposed, the ODS 316L studied is lower strength and has shorter rupture-life than its conventional counterpart. The HRTEM investigations indicated that small oxide particles, <15 nm in size, were coherent or semi-coherent with the steel matrix, whilst larger particles were incoherent.

A UO2-based salt target for rapid isolation of fission products

We report here an initial isolation study based upon the use of small uranium oxide particles dispersed in a soluble salt matrix to evaluate the relative recovery of fission products into acidic media. We further show that the macrostructures of the uranium microparticles are largely preserved, such that the bulk target material could be retained for additional irradiations or characterizations. Through this approach, fission products can be separated from the actinide-based target using low molarities of acid without the need to dissolve the actinide itself, reducing the amount of acidic waste. Extraction yields using two molarities of HCl and HNO3 are compared.

Elucidation of interface joining mechanism during friction stir welding through Cu/Cu-10Zn interfacial observations

A butt friction stir welding (FSW) process was performed on Cu and Cu-10Zn plates. Microstructural evolution along the Cu/Cu-10Zn interface retained in the FSW joint was systematically investigated in order to clarify the interface joining mechanism during the FSW. The initial joining interface is completely unbonded and has lots of large oxides distributed on it. The initial large oxides are then fragmented into small particles and the oxide layers initially formed on the interface are ruptured, which produces fresh surfaces on both the Cu and Cu-10Zn sides. The fresh surfaces are then joined at an atomic level under a compressive force perpendicular to the interface, while the small oxide particles are still dispersed on the interface with voids formed around the particles. A strain-induced grain boundary migration driven by the stored energy difference associated with the dislocation density difference will occur, which assists to extinguish the voids retained beside the oxide particles. Finally, a sound interface joining without oxide particles and large voids remaining on the interface is obtained during the FSW.

From Alloy to Oxide: Capturing the Early Stages of Oxidation on Ni-Cr(100) Alloys.

The interaction of oxygen with Ni-Cr(100) alloy surfaces is studied using scanning tunneling microscopy (STM) and spectroscopy (STS) to observe the initial steps of oxidation and formation of the alloy-oxide interface. The progression of oxidation was observed for Ni(100) and Ni-Cr(100) thin films including Ni-8 wt % Cr(100) and Ni-12 wt % Cr(100), which were grown on MgO(100) in situ. These surfaces were exposed to between 1 and 150 L O2 at 500 °C, and additional annealing steps were performed at 500 and 600 °C. Each oxidation and annealing step was studied with STM and STS, and differential conductance maps delivered spatially resolved information on doping and band gap distributions. Initial NiO nucleation and growth begins along the step edges of the Ni-Cr alloy accompanied by the formation of small oxide particles on the terraces. The incubation period known in oxidation of Ni(100) is absent on Ni-Cr alloy surfaces illustrating the significant changes in surface chemistry triggered by Cr-alloying. Step edge faceting is initiated by oxide decoration along the step edges and is expressed as moiré patterns in the STM images. The surface oxide can be characterized by NiONi(6 × 7) and NiO-Ni(7 × 8) coincidence lattices, which have a cube-on-cube epitaxial relationship. Small patches of NiO are susceptible to reduction during annealing; however, additional oxide coverage stabilizes the NiO. NiO regions are interspersed with areas covered predominantly with a novel cross-type reconstruction, which is interpreted tentatively as a Cr-rich, phase-separated region. Statistical analysis of the geometric features of the surface oxide including step edge heights, and NiO wedge angles illustrates the layer-by-layer growth mode of NiO in this pre-Cabrera-Mott regime, and the restructuring of the alloy-oxide interface during the oxidation process. This experimental approach has offered greater insight into the progression of oxide growth in Ni-Cr thin films and underscores the dramatic impact of alloying on oxidation process in the pre-Cabrera-Mott regime.

Macrophage uptake switches on OCT contrast of superparamagnetic nanoparticles for imaging of atherosclerotic plaques.

BackgroundOptical coherence tomography (OCT) is an intravascular, high-resolution imaging technique that is used to characterize atherosclerotic plaques. However, the identification of macrophages as important markers of inflammation and plaque vulnerability remains difficult. Here, we investigate whether the uptake of very small iron oxide particles (VSOP) in macrophages, that cluster in phagolysosomes and allow high-quality magnetic resonance imaging (MRI) of atherosclerotic plaques, and uptake of ferumoxytol nanoparticles enhance detection of macrophages by OCT.Materials and methodsRAW 264.7 macrophage cells were incubated with VSOP (1 and 2 mM Fe) that have been clinically tested and ferumoxytol (8.9 mM Fe) that is approved for iron deficiency treatment and currently investigated as an MRI contrast agent. The light scattering of control macrophages, nanoparticle-labeled macrophages (2,000,000 in 500 µL) and nanoparticle suspensions was measured in synchronous wavelength scan mode using a fluorescence spectrophotometer. For OCT analyses, pellets of 8,000,000 non-labeled, VSOP-labeled and ferumoxytol-labeled RAW 264.7 macrophages were imaged and analyzed on an OPTIS™ OCT imaging system.ResultsIncubation with 1 and 2 mM VSOP resulted in uptake of 7.1±1.5 and 12±1.5 pg Fe per cell, which increased the backscattering of the macrophages in spectrophotometry 2.5- and 3.6-fold, whereas incubation with 8.9 mM Fe ferumoxytol resulted in uptake of 6.6±2 pg Fe per cell, which increased the backscattering 1.5-fold at 700 nm. In contrast, backscattering of non-clustered nanoparticles in suspension was negligible. Accordingly, OCT imaging could visualize significantly increased backscattering and signal attenuation of nanoparticle-labeled macrophages in comparison with controls.ConclusionWe conclude that VSOP and, to a lesser extent, ferumoxytol increase light scattering and attenuation when taken up by macrophages and can serve as a multimodal imaging probe for MRI and OCT to improve macrophage detection in atherosclerotic plaques by OCT in the future.

Preparation of NiO nanoparticles in mesoporous silica via eutectic freezing and freeze-drying of aqueous precursor salts

Abstract Immobilization of small metal oxide particles on a solid support by impregnation with solutions of metal salts is a common route of catalyst preparation. Here we explore a modification of this route, based on eutectic freezing of the aqueous precursor salts in the pores of SBA-15, and removal of water/ice by freeze-drying. The two-solvents method was used to selectively fill the pore space of SBA-15 with precursor salts (nickel acetate or nitrate). A morphological and structural analysis of the nickel oxide formed in the pores after thermal decomposition of the salts was performed and compared to samples obtained via conventional solvent evaporation. Immobilized NiO nanocrystallites prepared via eutectic freezing appeared in two morphologies: (a) rodlike particles of ca 5 nm diameter, i.e., somewhat smaller than the pore diameter of SBA-15 (7 nm); (b) species detectable by powder XRD and energy-dispersive X-ray spectroscopy (EDXS), but not by TEM. Nitrogen adsorption isotherms are sensitive to the distribution of NiO in the pores: Pore blocking effects appear in the desorption branch for samples containing rodlike NiO particles, but not in samples in which no particles are detectable by TEM.

Self-cleaning mechanisms in ultrasonic bonding of Al wire

Real-time observations of the artificially increased oxide layer during the ultrasonic (US) bonding process were carried out to reveal the self-cleaning mechanisms. After the normal force loading, cracks occurred in the Al2O3 layer at the peripheral region of the wire/substrate interface and were perpendicular to the wire direction. As the US vibration started, the oxides started to detach from the pure metal surface and moved towards the middle of the contact area. With further vibration cycles, these detached oxides were milled from flakes into small particles. Due to three mechanisms including penetration, oxide flow and pushing, the small oxide particles were transported to the peripheral contact region or the outside of the contact area. When a metal splash existed, the flowing out of large amounts of oxides was facilitated. Pre-deformation originates cracks; vibration plays a significant role in detachment, milling, penetration and oxide flow; while the plastic deformation induced material flow is more critical on removing the oxides from the substrate by pushing. The shear tests showed that a 50 nm oxide coating could significantly enhance the Al-glass bonding strength by 2∼3 times.

The effect of NH3·H2O addition in Ni/SBA-15 catalyst preparation on its performance for carbon dioxide reforming of methane to produce H2

Three kinds of Ni catalysts loaded on SBA-15 were prepared by impregnation method, adding NH3·H2O or C2H2O4 in the impregnant, and applied to CO2 reforming (DRM) of methane to generate hydrogen at 750 °C. The results showed that the catalyst prepared with NH3·H2O addition exhibited high activity and stability. TEM, H2-TPR, XPS, XRD, and TG-MS characterization indicated that with addition of NH3·H2O (0.1 mol L−1) in the preparation process, small nickel oxide particles, with average size of about 7 nm, were obtained on the catalyst, and the strong association between support and Ni species made them uniformly dispersed, enabling the capacity to resist carbon deposition and metal sintering, which contributed to the excellent activity, stability and selectivity for the DRM to H2 production.

Application of Europium-Doped Very Small Iron Oxide Nanoparticles to Visualize Neuroinflammation with MRI and Fluorescence Microscopy

Our recent studies demonstrated that electrostatically stabilized very small superparamagnetic iron oxide particles (VSOPs) are promising MRI probes for detecting various pathological aspects of autoimmunity in the central nervous system (CNS). However, investigation of the precise tissue and cellular distribution of VSOP has been technically limited due to the need to use iron detection methods for VSOP visualization. Therefore, we assessed here the utility of europium (Eu)-doped VSOP as an MRI tool for in vivo investigations in the animal model experimental autoimmune encephalomyelitis (EAE), and as a tool to investigate histopathological processes in the CNS using fluorescence microscopy.We demonstrated that Eu-VSOP display the same properties as VSOP in terms of revealing inflammation-mediated changes by binding to brain endothelium in vitro, and in terms of visualizing brain lesions in EAE in vivo. MRI examinations with Eu-VSOP confirm that at peak disease particles accumulated inside the choroid plexus, and in cerebellar and meningeal lesions. Importantly, Eu-VSOP-based MRI showed for the first time in a longitudinal setup that particles were absent from the choroid plexus in mice during remission of EAE, but accumulated again during subsequent relapse. Within the choroid plexus, Eu-VSOP were associated both with monocytes/macrophages present in the plexus stroma, and associated with epithelial cells.Using Eu-VSOP, we demonstrated for the first time the involvement of the choroid plexus in relapses. Thus, Eu-VSOP have the potential to reveal various aspects of choroid plexus involvement in neuroinflammation, including monocyte recruitment from the blood and alterations of the choroid plexus epithelium.

Feasibility of application of iron zeolites for high-temperature decomposition of N2O under real conditions of the technology for nitric acid production

The long-term stabilities of a group of iron zeolites with MFI, *BEA, and FER structures and similar Fe/Al ratios were evaluated to assess their performance as catalysts for N2O decomposition. Conditions relevant for the application of the catalyst at the secondary level for N2O elimination, i.e., directly after the NH3 oxidation step of the process of nitric acid production, were investigated. These conditions included reaction temperatures of up to 900°C and the presence of high concentrations of water vapour, oxygen, and NO. The focus of the study was the comparison of the MFI and *BEA zeolites with the FER-based zeolite, a catalyst established as relatively stable under such conditions. The structural analysis of the individual zeolite frameworks and iron species involved a combination of several methods, and provided insight into the framework modification as well as identification and semiquantitative determination of the individual iron species. In the zeolite catalysts, these iron species were in the form of either isolated Fe(II) and Fe(III)-oxo ions, polynuclear Fe(III)-oxo complexes, or small Fe oxide particles. None of the zeolite structures displayed a high extent of structural collapse of the framework; thus, structural collapse does not explain the observed decrease in activity. An investigation of the kinetics of the N2O decomposition, both before and after ageing under relevant reaction conditions, proved the dominant role of isolated Fe(II) ions that were accessible to the reacting gas-phase molecules. The kinetic study also identified the differences in the ability of the three zeolites to stabilize the active sites in individual framework types during long-term exposure to challenging reaction conditions. It has been shown that, while the isolated Fe(II) ions were present in adequate concentration for N2O decomposition activity at the relevant temperature region in all three zeolite-based catalysts, the MFI and *BEA zeolites were not able to effectively stabilize the active iron structure during ageing for over 12days. In contrast, the FER framework survived a test for over 24days. The iron species formed in MFI and *BEA zeolites during ageing were mostly large FeOx species and displayed very low activity that approached the activity of FeOx clusters supported on SiO2.

MULTILAYER COMPOSITE PLASMA COATINGS ON SCREEN PROTECTION ELEMENTS BASED ON ZIRCONIUM DIOXIDE

The paper contains results of investigations pertaining to an influence of plasma jet parameters (current, spraying distance, consumption of plasma formation gas (nitrogen)), fractional composition of initial powder and degree of cooling with compressed air on anti-meteoric coating characteristics. Optimum modes (arc current 600 A; spray distance of 110 mm; consumption of plasma formation gas (nitrogen) – 50 l/min; fractional composition of zirconium dioxide powder &lt;50 μm; compressed air consumption for cooling – 1 m3/min; p = 4 bar) make it possible to obtain anti-meteoric coatings based on zirconium dioxide with material utilization rate of 62 %, total ceramic layer porosity of 6 %. After exposure of compression plasma flows on a coating in the nitrogen atmosphere a cubic modification of zirconium oxide is considered as the main phase being present in the coating. The lattice parameter of cubic zirconium oxide modification is equal to 0.5174 nm. Taking into consideration usage of nitrogen as plasma formation substance its interaction with zirconium coating atoms occurs and zirconium nitride (ZrN) is formed with a cubic crystal lattice (lattice parameter 0.4580 nm). Melting of pre-surface layer takes place and a depth of the melted layer is about 8 μm according to the results of a scanning electron microscopy. Pre-surface layer being crystallized after exposure to compression plasma flows is characterized by a homogeneous distribution of ele-ments and absence of pores formed in the process of coating formation. The coating structure is represented by a set of lar- ge (5–7 μm) and small (1–2 μm) zirconium oxide particles sintered against each other. Melting of coating surface layer and speed crystallization occur after the impact of compression plasma flows on the formed coating. Cracking of the surface layer arises due to origination of internal mechanical stresses in the crystallized part. While using a scanning electron microscopy a detailed analysis of the surface structure has permitted to reveal a formation of a cellular structure with an average cell size of less than 1 μm in the crystallized portion and formation of the cells can be caused by speed crystallization of the melted layer.

SnO2 decorated SiO2 chemical sensors: Enhanced sensing performance toward ethanol and acetone

SnO2 decorated SiO2 chemical sensors with different Sn/Si ratios were synthesized by micro-emulsion followed by ultrasonic-assisted deposition-precipitation method and used for highly sensitive and selective detection of ethanol and acetone. XRD, EDS, SEM, and TEM were used to characterize the samples. The results confirm deposition of small crystalline tin oxide particles on the surface of silica particles. Using these formed materials for detection of ethanol and acetone resulted in significant enhancement of the sensitivity and reducing temperature of maximum response in comparison to the pure SnO2. The selectivity of the sample with the highest sensitivity to ethanol and acetone, i.e. 80wt% SnO2/SiO2, was examined by measuring its sensitivity to some interfering gases including carbon monoxide, methane, toluene, Trichloroethylene (TCE) and propane; the results showed very high selectivity of the sensor to ethanol and acetone, especially at low temperatures. The sensor responses to traces of acetone in the air with the concentration ranging from 0.5 to 5ppm at different temperatures of 70, 170 and 270, and 370°C were measured to evaluate the capability of the sensor for detection of acetone in the breath of human, which is helpful in the diabetes diagnosis. The sensor could effectively show high enough sensitivity even to these very low concentrations of acetone which reveals its high potential for being used in acetone detection devices. Finally, the effect of humidity on the sensitivity of sensor to acetone was investigated. Increasing the humidity of background air, caused the sensor response to decrease and the operating temperature of maximum response of the sensor to increase.