Oxygen Vapor Research Articles

(Bio)polymer/ZnO Nanocomposites for Packaging Applications: A Review of Gas Barrier and Mechanical Properties.

Nanotechnology is playing a pivotal role in improving quality of life due to its versatile applications in many areas of research. In this regard, nanoparticles have gained significant importance. Zinc oxide nanoparticles (ZnO NPs) amongst other nanoparticles are being used in producing nanocomposites. Methods like solvent casting, solution casting, solvent volatilization, twin-screw extrusion, melt compounding and extrusion blow molding have been applied to produce ZnO NPs based (bio)polymer composites. These composites are of great interest in the research area of food packaging materials due to their improved multifunctional characteristics like their mechanical, barrier and antimicrobial properties. This paper gives an overview of the main methods to synthesize ZnO NPs, methods to incorporate ZnO NPs in (bio)polymers, and finally, the gas barrier and mechanical properties of the nanocomposites. As a conclusion, a maximum decline in oxygen, carbon dioxide and water vapor permeability was reported as 66%, 17% and 38% respectively, while tensile strength and young’s modulus were observed to increase by 32% and 57% respectively, for different (bio)polymer/ZnO nanocomposites.

Accurate Predictions of Volatile Plutonium Thermodynamic Properties.

The ability to predict the nature and amounts of plutonium emissions in industrial accidents, such as in solvent fires at PUREX nuclear reprocessing facilities, is a key concern of nuclear safety agencies. In accident conditions and in the presence of oxygen and water vapor, plutonium is expected to form the three major volatile species PuO2, PuO3, and PuO2(OH)2, for which the thermodynamic data necessary for predictions (enthalpies of formation and heat capacities) presently show either large uncertainties or are lacking. In this work we aim to alleviate such shortcomings by obtaining the aforementioned data via relativistic correlated electronic structure calculations employing the multi-state complete active space with second-order perturbation theory (MS-CASPT2) with a state-interaction RASSI spin-orbit coupling approach, which is able to describe the multireference character of the ground-state wave functions of PuO3 and PuO2(OH2). We benchmark this approach by comparing it to relativistic coupled cluster calculations for the ground, ionized, and excited states of PuO2. Our results allow us to predict enthalpies of formation ΔfH⊖(298.15 K) of PuO2, PuO3, and PuO2(OH)2 to be -449.5 ± 8.8, -553.2 ± 27.5, and -1012.6 ± 38.1 kJ mol-1, respectively, which confirm the predominance of plutonium dioxide but also reveal the existence of plutonium trioxide in the gaseous phase under oxidative conditions, though the partial pressures of PuO3 and PuO2(OH)2 are nonetheless always rather low under a wet atmosphere. Our calculations also permit us to reassess prior results for PuO2, establishing that the ground state of the PuO2 molecule is mainly of 5Σg+ character, as well as to confirm the experimental value for the adiabatic ionization energy of PuO2.

Decomposition of Nitrous Oxide over Cu/TiO2 Catalysts: The Effect of Cu Loading, TiO2 Structure, and Reaction Conditions

Decomposition of nitrous oxide (N2O) over titania (TiO2) supported copper (Cu) catalyst was investigated with the existence of oxygen and water vapor. The catalytic activity of TiO2 was promoted by copper loading. It was found that there are optimum levels of copper loading on TiO2, and these values are correlated to the specific surface area of TiO2 support being used. The relationship between the catalytic activity for decomposition of N2O and the crystal structure of TiO2 was also investigated. The result revealed that Cu/TiO2 catalysts with the rutile structure has a higher activity toward N2O decomposition than those with the anatase structure. In this research, Cu(5wt%)/TiO2 prepared from TiO2 JRC-TIO-4 (reference catalyst provided by Catalysis Society of Japan) which was mainly constituted of rutile showed the highest activity for N2O decomposition and it could decompose N2O completely at 650℃. The catalytic activity was inhibited by the existence of oxygen. However, there was no influence of water vapor to the catalytic activity of Cu/TiO2 for N2O decomposition.

Dynamic Enhancement of Nitric Oxide Radioluminescence with Nitrogen Purge

Remote detection of alpha radiation is commonly realised by collecting the light, the radioluminescence, that is produced when alpha particles are stopped in air. Radioluminescence of nitric oxide (NO) is primarily emitted between 200 nm and 300 nm, which makes it possible to use it for remote detection under daylight conditions. Quenching by ambient oxygen and water vapour, however, makes it generally difficult to effectively create NO radioluminescence. We present the detection of intense NO radioluminescence in ambient air under standard indoor lighting conditions using a nitrogen purge. The nitrogen contained NO impurities that were intrinsic to the gas and had not explicitly been added. We study the mechanisms that govern the NO radioluminescence production and introduce a model to describe the dynamics of the process. The level of NO contained in the gas was found to determine how successful a purge can be. We conclude by discussing possible applications of the technique in nitrogen-flushed gloveboxes at nuclear facilities where NO concentration of 100 ppb–1 ppm would be sufficient for efficient optical alpha radiation detection in standard lighting conditions.

Nanoparticles of zinc stannates (ZTO): Synthesis, characterization and electrical behavior in oxygen and acetone vapors

Zinc stannate (ZTO) ceramic powders were synthesized by a modified Pechini method. The nanoparticles synthesized at 900 °C were characterized using thermal analysis (TGA/DTA), infrared (IR), UV–Vis absorption and Raman spectroscopies, photoluminescence (PL), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Characterization revealed a mixture of phases of perovskite-type ZnSnO3 and spinel cubic Zn2SnO4, with a primary particle size of <50 nm, and a gap energy of ~4.10 eV. Using the obtained ceramic powders, green pieces were formed by slip casting and sintered at 1200 °C and 1400 °C. Finally, the effect of the presence of oxygen and acetone atmospheres on the electrical response of the sintered ZTO pieces at 1200 °C was evaluated. The tests showed an appreciable variation in the resistance of the samples on altering the nature of the atmosphere of the gas surrounding the piece, indicating good sensory capacity of the ZTO pieces to these gases.

Permeation characterization and modelling of polyethylene/clay nanocomposites for packaging

The approach of upgrading barrier properties of polymer with nanofillers is effectual and well established now-a-days to manufacture films and quality packaging. This research deals with enhancement of barrier attributes of clay-based high density polyethylene nanocomposites against oxygen and water permeability. Na-Montmorillonite and two grades of kaolin clays were used for HDPE/clay nanocomposites preparation in twin-screw extruder with temperature profile of 160, 170, 180, 190 and 200 °C along the extruder at 110 rpm with clay loading up to 10 wt%. The extent of maximum reduction in water and oxygen vapors permeation was more prominent at 5 wt% sample of each clay. XRD analysis revealed no exfoliation in kaolin clay samples but indicated presence of exfoliation in Na-MMT samples. SEM and TEM micrographs revealed nano-level dispersion for both kaolin clays and Na-MMT and agglomerate formation at high wt% of clays. Experimental data for oxygen and water vapors permeation through nanocomposites were fitted on Nielsen, Cussler and Gusev–Lutsi models. Modelling of barrier performance was utilized for acquiring aspect ratio of filler for nanocomposites. Maximum and average aspect ratio of fillers and third-degree polynomial equation for nanocomposite, through curve fitting, were determined to predict improved barrier properties of nanocomposites.

Experimental investigations on the effects of water vapor and oxygen concentrations in the ambience on the burning constant, lifetime and residuals of single isolated xylene, isobutanol and ethanol droplets

During spray combustion, the complex oxidizing atmosphere makes the direct experimental investigation of droplet evaporation and combustion challenging. Within this study, the effects of water vapor as well as the concentrations of oxygen and nitrogen in the atmosphere on the single isolated droplet combustion were experimentally investigated using a high-speed digital camera. An in-house made piezoelectric droplet-on-demand generator was employed to reproducibly generate single isolated monodispersed droplets with the diameter of around 100 µm. Three fuels with different boiling points and solubility in water were used. The results indicate that, increasing oxygen concentration promotes droplet combustion, and water vapor alters the droplet combustion depending on the fuel properties. The experimental values of the burning constant during the quasi-steady period were in agreement with the d2-law based theoretical calculations. The residuals from ethanol droplet combustion can be clearly observed, whose formation can be affected by the oxygen and water vapor in the atmosphere.

Modeling Proton Exchange Membrane Fuel Cell Cathode Catalyst Layers with the Lattice-Boltzmann-Method Framework

In this work, a coupled Lattice-Boltzmann-Method and electrochemistry Direct-Numerical-Simulation model for a proton exchange membrane (PEMFC) electrode has been presented. One of the main challenges affecting study of the cathode catalyst layer (CCL) in PEMFCs is the lack of detailed understanding of species transport and how it affects electrochemical performance. Researchers have typically used high level approximations that oversimplify the microstructure of the CCL—these are known as macrohomogenous models. However, as the field has progressed, these idealizations have begun to show their flaws, especially in areas of improving catalytic performance with lower Pt-loadings and non-noble metal catalysts. Previously, the microstructure details needed to build an accurate mesoscale model have eluded researchers; however, with advances in tomography and focused-ion-beam scanning-electron-microscopy (FIB-SEM), creating these representations has become possible. Mesoscale modeling in the CCL has been traditionally approached through either the Lattice-Boltzmann-Method (LBM) or electrochemistry coupled Direct-Numerical-Simulation (DNS). These models have been underutilized in the fuel cell community due to their complexity and resource intensiveness; however, with advances in parallel computing, this has become not only a possibility, but a necessity for modeling phenomena such as low platinum loadings and interfacial effects. With these new advances, a synergistic modeling approach can be taken that combines the advantages of each method. This can shed light on the transport and degradation phenomena in PEMFCs, particularly catalyst layer considerations and carbon support corrosion. Here, the liquid water as well as gaseous oxygen, nitrogen, and water vapor profiles through segmented geometries made of tomography measurements from FIB-SEM were shown through LBM. This is shown in Figure 1, where the capillary pressure is varied in six stages from 1.8 MPa to 20 MPa, which shows a saturation increase from 5% to 60%, respectively. This diagram shows the capillary fingering regime we should expect through the porous media. Additionally, these same geometries were used to simulate electrochemical phenomena, such as reaction profiles, polarization curves, ionomer thickness, and many others. Additionally, to examine the effects of ionomer coverage on different interfaces, a physics-based model using erosion was used to add in the ionomer, as FIB-SEM is unable to differentiate between ionomer, Pt, or carbon support. Once in, on the LBM side, we can model the ionomer by changing its contact angle compared to the carbon support (hydrophilic or around 10° for the ionomer compared to hydrophobic or 110° to 140° for the support), whereas for DNS, it is taken into account by considering Henry’s law and other transport phenomena. Finally, to account for accurate liquid formation throughout the geometry according to the Pt distribution, a source term was included in the LBM model and then transferred to DNS to create one of the first numerically intensive frameworks for a PEMFC electrode available. Figure 1

Development of an Oxygen Sensitive Model Gel System to Detect Defects in Metal Oxide Coated Multilayer Polymeric Films

Metal oxide coated multilayered polymeric pouches provide a suitable alternative to foil-based packaging for shelf-stable products with extended shelf-life. The barrier performance of these films depends upon the integrity of the metal oxide coating which can develop defects as a result of thermal processing and improper handling. In this work, we developed a methodology to visually identify these defects using an oxygen-sensitive model gel system. Four pouches with different metal oxide coatings: MOA (Coated PET), MOB (SiOx -coated PET), MOC (Overlayer-AlOx -Organic-coated PET), MOD (Overlayer-SiOx -coated PET) were filled with water and retort-processed for 30 and 40 min at 121 °C. After processing, the pouches were cut open, dried and subsequently filled with a gel containing methylene blue that changes color in the presence of oxygen. The pouches were then stored at 23 and 40 °C for 180 and 90 days, respectively. Defects were identified by observing the localized color change from yellow to blue in the packaged gel. These observations were confirmed through measurement of oxygen and water vapor transmission rates, as well as SEM and CLSM analyses. The MOC pouches showed the least change in barrier properties after thermal processing. This was due to crosslinking in the organic coating and protection provided by the overlayer. The melting enthalpy of all films increased significantly (P < 0.05) after sterilization. This may increase the brittleness of the substrates after processing. Findings may be used to improve the barrier performance of metal oxide coated polymeric films intended for food packaging applications. PRACTICAL APPLICATION: In this study, we developed a methylene blue-based, oxygen-sensitive model gel system to identify defects in metal oxide coated polymeric structures induced by thermal processing and mechanical stresses. We also performed a comprehensive analysis of these defects through CLSM and SEM. The gel system and methodology developed may be useful in the design and development of high barrier metal oxide coated films.

Determining Shelf Life of Ready-to-Eat Macaroni and Cheese in High Barrier and Oxygen Scavenger Packaging Sterilized via Microwave-Assisted Thermal Sterilization

Ready-to-eat macaroni and cheese filled in novel oxygen scavenger and metal oxide–coated high-barrier polymer packages were processed in pilot scale 915-MHz microwave-assisted thermal sterilization system (MATS). Also, aluminum foil packages were processed in Allpax retort system to compare packaging performance. Physicochemical and sensory attributes of macaroni and cheese packaged in different oxygen and water vapor transmission rates were evaluated and stored for 6 months at 37.8 °C. Findings showed oxygen transmission rate (OTR) increase by 2–7 times and water vapor transmission rate (WVTR) increase by 2.5–24 times after MATS processing. OTR of polymeric packaging had no significant effect on vitamin A and vitamin E, shear force, and food color. Comparable results between polymeric and aluminum foil packaging were observed throughout the shelf life. This indicates that oxygen scavenger and high-barrier packaging with OTRs ~ 0.03–0.34 cc/m2 day and WVTRs ~ 0.62–7.19 g/m2 day can be used for ready-to-eat meals with extended shelf life for soldiers and astronauts.

Development of blown polylactic acid-MgO nanocomposite films for food packaging

Hitherto the unreported development of blown PLA/MgO nanocomposite (NC) food packaging films, employing an industrial level melt-processing setup is presented. 5 wt% reinforced PLA/MgO NC extrudates are prepared at first, to assess the feasibility of production of large quantity of blown films by the extrusion method. Based on successful outcomes of the preliminary trials, up to 3 wt% PLA/MgO NC films are eventually prepared for testing and characterization of key mechanical, barrier, optical, thermal and anti-bacterial properties. The tensile strength and plasticity are found to improved by nearly 22% and 146% respectively for the 2 wt% MgO reinforced films. The oxygen and water vapour barrier properties improve by nearly 65% and 57% respectively for the 1% formulation. For the 1 wt% NC films around 44% E. coli bacteria are killed after 24 h treatment. Overall, this research establishes the successful production of large scale, sustainable, blown PLA/MgO NC food packaging films.

Electrochromic properties of rhodium oxide thin films prepared by reactive sputtering under an O2 or H2O vapor atmosphere

Rhodium (Rh) oxide thin films were prepared by reactive sputtering at different substrate temperatures under an oxygen or water (H2O) vapor atmosphere, and their crystal structure, density, optical properties, and electrochromic properties were investigated. The film density decreased with decreasing substrate temperature, and the lowest density of 4.2 g/cm3 was obtained for the film deposited at −20 °C under a H2O vapor atmosphere. The Rh oxide films deposited at −20 °C under a H2O vapor atmosphere showed anodic electrochromism between light yellow and olive i.e., bleached and colored states, respectively using an aqueous 1 M potassium hydroxide as the electrolyte; these films also exhibited the largest transmittance change, of 26%, at a wavelength of 600 nm.

Administering Anesthesia to Mice, Rats, and Hamsters.

Anesthesia is used to sedate animals during injections or during operations where unexpected or rapid movements would endanger the animal. Inhalant anesthetics are often the most appropriate choice to achieve anesthesia that meets the clinical and humane needs without interfering with the scientific goals of the research protocol. Isoflurane (i.e., halogenated ether)-the preferred inhalant anesthetic for small animals-is administered either by placing the animals in a closed container permeated with a mixture of isoflurane and oxygen vapor, or by using a mask (for larger animals). The depth of anesthesia is easy to assess and to control. Animals sedated by isoflurane can be handled for injections or simple operations.

Effect of crystallinity, crystal polymorphism, and graphene oxide nanosheets on the barrier properties of poly (l-lactic acid)

In this study, the effects of crystallinity, crystal polymorphism, and graphene oxide nanosheets (GONS) on the oxygen and water vapor permeability of PLLA were investigated. It was revealed that for the pristine PLLA with a crystallinity degree of 40%, the oxygen and water vapor permeability decreased by about 48% and 30%, respectively. Also, by changing the crystal form from α′ to α in a constant crystallinity ratio, the oxygen and water vapor permeability decreased by about 10% and 28%, respectively. PLLA/GO nanocomposites with various compositions were prepared by solution coagulation. Results of the permeability analysis on nanocomposites showed that in the presence of 1 wt% GONS, the oxygen and water vapor permeability of PLLA films decreased by about 80% and 30% respectively. In addition, the simultaneous effect of crystallinity and the presence of GONS was investigated, demonstrating that the simultaneous presence of crystalline structures with nanosheets caused the gas pathways to prolong immensely, and for the sample containing 1 wt% nanosheets with about 35% of crystallinity, the rate of oxygen permeation and water vapor transmission decreases by about 90% and 60%, respectively. The Nielsen, Bharadwaj, Duan & Thomas, and Tan & Thomas models were used for comparing these results.

Application of clay-TiO2 nanocomposite packaging films on pears (Prunus communis L. cv. Williams) under cold storage

Today, nanomaterials are presenting novel characteristics can be applied in developing new packaging with modified preferred properties. These are including the development of packaging with improved barrier characteristics which will extend the storage life of a product. In the present study, the effect of three types of developed low-density polyethylene nanocomposite films with two types of TiO2 (anatase and rutile) and clay (Closite 20A) nanoparticles were evaluated on the quality parameters of pear fruit (cv. ‘Williams’) during 48 days of storage at 4 °C. The Mechanical test revealed that the reinforcement in the presence of the nanocomposites was more than that with their conventional counterparts. The barrier properties against oxygen, carbon dioxide and water vapor of nanocomposite films were significantly decreased. The results showed that nanocomposite packaging film (NPFs) was a promising oxygen, carbon dioxide and water vapor barrier. Weight loss, firmness and the total solids content of pear in clay/TiO2-nanocomposite film decreased at the rates of 50%, 39% and 13%, respectively due to the modified atmosphere. Higher ascorbic acid content, lower ethylene production, reducing sugar content and PPO activity and higher POD of the packed fruits were observed in clay/TiO2-nanocomposite film. The single use of clay and TiO2 nanoparticles was not as effective as both of them in increasing durability of pear fruits. So, clay/TiO2-nanocomposite film can be considered as a practical approach to reduce the risk of pathogens, contamination and to improve the maintenance quality of pear fruit during the storage.

Use of poly(ε-caprolactone)-based films for equilibrium-modified atmosphere packaging to extend the postharvest shelf life of garland chrysanthemum.

A uniaxial‐stretched poly(ε‐caprolactone)/poly(propylene carbonate; PCL/PPC) composite film was prepared using a twin‐screw extruder, and its utility as an equilibrium‐modified atmosphere packaging (EMAP) film extending the shelf life of garland chrysanthemums stored at 2~4°C was explored. The oxygen, carbon dioxide, and water vapor penetration properties, mechanical properties, and gas permselectivity of PCL/PPC film used to package garland chrysanthemums were determined and compared to those of controlled low‐density polyethylene (LDPE) and PCL films. Physicochemical properties such as package headspace gas composition, weight loss, leaf color, total chlorophyll content, ascorbic acid content, lipid peroxidation extent, and the sensory traits of garland chrysanthemums were investigated over a storage period of 14 days to compare the preservative effects of the various packages. PPC blending decreased the PCL gas and water vapor permeability and slightly increased the CO 2 permselectivity. These effects on gas and water vapor permeability, combined with the effects on gas permselectivity, enhanced preservation of packed garland chrysanthemums. Furthermore, an O2 inner atmosphere level of 2%~5%, and a CO 2 concentration not greater than 8%, was established by the PCL/PPC film in the absence of condensation. The results thus suggest that biodegradable film can be used as an EMAP film to better maintain the quality of freshly harvested garland chrysanthemums and to afford a longer shelf life during cold storage compared to LDPE film. Sensory evaluation indicated that the garland chrysanthemums were market‐acceptable after 14 days of storage; LDPE‐packed chrysanthemums were acceptable only up to 8 days of storage. The film thus improved storage life compared to that afforded by LDPE.

Hydrogen-Assisted Sputtering Growth of TiN on Ceramic Substrates

Titanium nitride (TiN) has mechanical and electrical characteristics applicable for very large scale integration (VLSI) and discrete electronic devices. This study assessed the effect of hydrogen on sputtering growth of TiN on ceramic substrates. Although ceramic substrate is used in discrete device applications due to its insulating property, ceramic is also porous and contains oxygen and water vapor gases, which can be incorporated into TiN films during growth. In addition, discrete devices are usually packaged in glass sealing at 700 °C, and reaction with the trapped gases can significantly degrade the quality of the TiN film. In order to evaluate ways to minimize the effects of these gases on TiN, hydrogen gas was introduced during sputtering growth. The main hypothesis was that the hydrogen gas would react with oxygen to lower the oxygen density in the vacuum chamber, which would suppress the effects of the trapped gases in the ceramic and ultimately improve the quality of the TiN film. Improvements in TiN quality were confirmed by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and resistance measurements. During the glass-sealing process, N2-purging at 400 °C was effective at keeping the TiN in a low resistance state. These results show that introducing hydrogen gas during sputtering growth could solve the problems caused by ceramic substrates.

Comparison of protective supports and antioxidative capacity of two bio-based films with revalorised fruit pomaces extracted from blueberry and red grape skin

Abstract This work aimed to develop novel food packaging materials following eco-friendly concept. Chitosan (CS) and carboxymethyl cellulose (CMC) based films were developed with blueberry (B) and red grape skin pomace extracts (P) rich in antioxidants at different concentrations (1, 2 and 4% w/v). Physico-chemical (thickness, oxygen and water vapour permeability, solubility and moisture content) and antioxidant film properties and activities were determined. Adjustments in film formulations and quantity of plasticizer were done in order to obtain smooth films that are easy to manipulate and without cracks and mechanical failures. The extract of blueberry had higher levels of total phenolics, however films had lower antioxidant activity compared to red grape skin extracts, and the CMC resulted in more active films in the three concentrations of bioactives incorporation tested. On the other hand, with the extract of grape skin that had lower content of total phenolics, the films presented greater antioxidant activity, and the CS matrix, in general, showed more active efficacy. Both matrices showed antioxidant activities directly proportional to total phenolic contents incorporated into the films, being more effective those of CS containing 4% red grape skin pomace extract. The addition of red grape skin extracts increased oxygen permeability for 3 orders of magnitude in CMC films while it didn’t influence OTR in CS films expect for 4% extract. Similarly, addition of blueberry extract significantly increased OTR only in 4% CMC films and one order of magnitude in CS films. The addition of extracts slightly changed WVP of control films.

Efficient gas-phase purification using chloroform for metal-free multi-walled carbon nanotubes

Gas-phase treatments using chloroform (CHCl3) and water vapor were used to remove metal impurities (MIs) from as-prepared multi-walled carbon nanotubes (AP-MWCNTs), which is a non-destructive way to produce highly pure CNTs with extremely low MI content and with retention of CNT properties. After purification using CHCl3, the MIs in the AP-MWCNTs had significantly decreased to 12 ppm, representing a purification efficiency of 99.8%. This purification method, applicable to various AP-MWCNTs with high contents and different compositions of MIs, is more effective than liquid-phase purification using acids and does not damage the CNT structure and morphology. This moderate purification is due to a combination of factors. Chlorine radicals and hydrochloric acid from the thermal decomposition of CHCl3 react with MIs encased by graphitic carbon layers to form metal chlorides that sublime at high temperature. Hydrogen, oxygen, and water vapor generated during the formation of the metal chlorides etch graphitic carbon layers and lead to the formation of new pores and cracks, which provide fast reaction and diffusion paths. During metal purification, the MWCNT surface becomes lightly coated with chlorine or chlorinated carbon, which are eliminated from the surface post-treatment using water vapor.

Selectivity improvement towards hydrogen and oxygen of solid electrolyte sensors by dynamic electrochemical methods

Solid electrolyte sensors (SES) based on yttria-stabilized zirconia (YSZ) can exhibit improved selectivity to redox active gases when they are operated with dynamic electrochemical methods like cyclic voltammetry (CV) or impedance spectroscopy (IS). To clarify basic electrochemical processes at the measuring electrode, experiments in the temperature range 650–750 °C with precise control of hydrogen, oxygen, and water vapor concentrations in non-equilibrated gas mixtures have been conducted. The results show that it is possible to detect hydrogen and oxygen selectively in oxidizing and in reducing gas mixtures with SES operated with CV at different scan rates and polarization ranges.Hydrogen-related peaks appear during anodic scan direction at potentials between -0.4 and -0.2 V vs. Pt/air reference and scan rates between 10 and 100 mV/s. Their heights increase with H2-concentration, temperature, and negative shift of the negative CV limit, providing a lower limit of detection below 5 vol.-ppm and an upper limit of detection at around 100 vol.-ppm at 700 to 750 °C. Oxygen-related peaks arise in cathodic scan direction at potentials between -0.1 and -0.4 V and scan rates between 100 and 1000 mV/s. Their heights also increase with O2-concentration and temperature, providing a lower limit of detection below 5 vol.-ppm and an upper limit of detection above 200 vol.-ppm at 650 °C. Water vapor causes decreasing H2-related peak heights, suggesting an occupation of electrode surface places needed for H2 reaction. In contrast to that, additionally conducted impedance spectroscopy experiments in the frequency range from 0.2 to 105 Hz did not provide further information about the selective detection of hydrogen and oxygen in non-equilibrated gas mixtures.