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To alleviate the destructive alteration of the glass layer surface caused by gas evolution during the oxygen‐blocking process of the HfB2‐MoSi2‐SiC coating, CeO2 was incorporated to modify HfB2‐MoSi2‐SiC coating, and the anti‐oxidation mechanism at 1700°C in air was investigated. Compared with the unmodified HfB2‐MoSi2‐SiC coating, the addition of the refractory CeO2 to the Hf‐B‐Si‐O system leads to the formation of a stable Hf‐Ce‐B‐Si‐O complex phase glass, which substantially enhances the viscosity, stability, and self‐healing sealing properties of the glass layer. The introduction of 0.75 vol.% CeO2 significantly lowers the oxidative activity of the HfB2‐MoSi2‐SiC coating, boosting its average protective efficiency to 99.96% and reducing the maximal oxygen permeability by 43.48%, thus exhibiting superior oxygen‐blocking performance. However, excessive addition of CeO2 leads to an overabundance of oxygen release through its distinctive oxygen vacancy mechanism, which accelerates the formation of Hf‐oxides, resulting in excessive viscosity on the coating surface and leaving oxidation defects unrepaired. [ABSTRACT FROM AUTHOR]

Ce 0.8 Sm 0.2 O 2-δ (wt.70 %)-Sm 0.6 Sr 0.4 Fe 1- x Cu x O 3-δ (wt.30 %) (SDC-SSFC) dual-phase oxygen permeable membranes were prepared by one-pot EDTA-citric acid combined complexing method. Effects of copper doping content on crystallographic phase, microstructure and oxygen permeability were deeply investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDXS). Systematic studies reveal that SDC as oxygen ion conductors and SSFC as electron conductor display an excellent synergistic effect only if a suitable doping content of copper was adopted. It can be found that Ce 0.8 Sm 0.2 O 2-δ -Sm 0.6 Sr 0.4 Fe 0.9 Cu 0.1 O 3-δ exhibits the highest oxygen permeation flux of up to about 0.61 ml cm−2 at 950 °C and lower oxygen permeation activation energy, which displays nearly a two-fold increase in oxygen permeability compared with the sample without any copper doping. If the copper doping content in B-site of SSFC perovskite exceeds about 30 %, a third phase, i.e., CuO, would appear in the bulk of SDC-SSFC dual-phase membrane and the grain size of CuO tend to gradually increase which would degrade the oxygen permeability of SDC-SSFC dual-phase membrane. Kinetical analysis showed that the critical membrane thickness (L c) of Ce 0.8 Sm 0.2 O 2-δ -Sm 0.6 Sr 0.4 Fe 0.9 Cu 0.1 O 3-δ membrane is close to approximately 0.6 mm, i.e., if the membrane thickness is larger than 0.6 mm, its rate-determining step would transform into the bulk-diffusion exchange from surface exchange. Meanwhile, Ce 0.8 Sm 0.2 O 2-δ -Sm 0.6 Sr 0.4 Fe 0.9 Cu 0.1 O 3-δ membrane exhibits a stable oxygen permeation flux of up to 0.32 ml cm−2·min−1 in pure CO 2 atmosphere for more than 120 h without any degradation. [ABSTRACT FROM AUTHOR]

The main weakness of non-silicone hydrogel contact lenses is their low oxygen permeability (Dk). Hence, we have tried to optimize their Dk using various concentrations and lengths of the poly (ethylene glycol) dimethacrylate crosslinker in a mixture of N,N-Dimethylacrylamide and Cyclohexyl methacrylate monomers. After synthesizing the different contact lenses, we evaluated their chemical, optical, and mechanical properties. The resultant non-silicone hydrogel contact lenses presented similar high water contents (75.69–80.60%) and adequate optical (e.g., a transmittance ranging from 85.91% to 99.91% and a refractive index between 1.3630 and 1.3740) and elongation at break (178.95–356.05%) characteristics for clinical applications. Conversely, they presented high contact angles (81.00–100.00°) and a low Young's modulus (0.066–0.167 MPa). Regarding the impact of the crosslinking modifications, the water content, contact angle, refractive index, transmittance, and Young's modulus of the synthesized lenses were slightly affected by crosslinker conditions. In contrast, the elongation at break (178.95–356.05%) and, more importantly, the oxygen permeability, which reached values of up to 73.90 Fatt units, were considerably impacted by the crosslinker conditions. To our knowledge, this study demonstrates for the first time that, in addition to water, other usual hydrogel components, like crosslinkers, can modulate the Dk of non-silicone contact lenses. It also provides a simple and scalable method to fabricate more permeable non-silicone lenses. [ABSTRACT FROM AUTHOR]

Abstract Green tea is renowned for its exceptional freshness; nevertheless, preserving its freshness poses a formidable challenge during storage due to its susceptibility to environmental factors. However, the effect of storage factors on freshness quality of green tea remains unclear, particularly with a lack of research studies regarding aroma quality and associated volatiles. In this study, we investigated the effects of oxygen scavenger, temperature, and packaging materials on freshness quality of packaged green teas during storage. The sensory freshness and corresponding volatile metabolites of the samples were investigated; the sensory‐chemical changes among packaged green teas during storage under different treatments were further explored. The freshness preservation in packaged green teas can be effectively achieved through the implementation of low‐temperature storage, packaging with oxygen scavenger and utilizing packaging with minimal oxygen permeability. A total of 151 volatile compounds were detected in all samples, among which 104 volatiles were identified as key contributors for distinguishing sample groups under 3 different treatments. The presence of volatiles with green, spicy, minty, and vegetable notes was found to be positively correlated with high freshness quality observed in packaged green tea. Conversely, an increase in volatiles characterized by fruity, sweet, fatty, and alkane notes was associated with the freshness deterioration. The volatiles changes that lead to freshness deterioration occurred especially under conditions of elevated temperature and increased oxygen levels, predominantly involving fat degradation, lipid oxidation, the Maillard reaction, carotenoids degradation, and dehydration reactions. The findings provide a theoretical foundation for the advancement of storage technology in packaged green teas.

High-entropy perovskite materials (HEPMs), characterized by their multi-element composition and highly disordered structure, can incorporate multiple rare earth elements at the A-site, producing perovskites with enhanced CO2 resistance, making them stay high performance and structurally stable in the CO2 atmosphere. However, this modification may result in reduced oxygen permeability. In this study, we investigated La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.8Fe0.2O3-δ (L0.2M1.8) high-entropy perovskite materials, focusing on enhancing their oxygen permeability in both air and CO2 atmospheres through strategic design modifications at the B-sites and A/B-sites. We prepared Ni-substituted La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.7Fe0.2Ni0.1O3-δ (L0.2M1.7N0.1) HEPMs by introducing Ni elements at the B-site, and further innovatively introduced A-site defects to prepare La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.7Fe0.2Ni0.1O3-δ (L0.1M1.7N0.1) materials. In a pure CO2 atmosphere, the oxygen permeation flux of the L0.1M1.7N0.1 membrane can reach 0.29 mL·cm−2·min−1. Notably, the L0.1M1.7N0.1 membrane maintained a good perovskite structure after stability tests extending up to 120 h under 20% CO2/80% He atmosphere. These findings suggest that A-site-defect high-entropy perovskites hold great promise for applications in CO2 capture, storage, and utilization. [ABSTRACT FROM AUTHOR]

This study focuses on mixed‐conducting perovskite membranes for efficient oxygen supply, aiming to replace energy‐intensive cryogenic distillation with a more practical alternative. A La and Nb co‐doped BaCoO3−δ perovskite is introduced, Ba0.95La0.05Co0.8Fe0.12Nb0.08O3−δ (BLCFN) with a record‐breaking oxygen permeation flux, surpassing all known single‐phase perovskite membranes. To elucidate its superior membrane performance, the mass/charge transport properties and equilibrium bulk properties are investigated and quantitative indicators (DO = 5.8 × 10−6 cm2 s−1, kO = 1.0 × 10−4 cm s−1, σion = 0.93 S cm−1 at 900 °C) reveal fast diffusion and excellent surface gas‐exchange kinetics. The oxygen permeability of 12.4 mL cm−2 min−1 and over 200 h of long‐term stability is achieved in an air/He atmosphere at 900 °C. By presenting a material that demonstrates higher performance than Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF), currently known for its highest permeability, it is believed that this marks a significant step toward innovative performance enhancement of perovskite oxide‐based membranes. [ABSTRACT FROM AUTHOR]

This study examines the preparation and characterization of Poly lactic acid (PLA)/Poly(ε-caprolactone) (PCL) blends with the addition of glycidyl methacrylate (GMA) as a chain extender, as well as nanocomposites of compatibilized and uncompatibilized PLA/PCL with nanocalcium carbonate (NCC). The blend compositions included 2 and 3 phr of GMA, while the nanocomposites contained 7 and 9 phr of NCC. The samples were processed via melt mixing, and their crystallinity, tensile properties, morphology, permeability, migration, and rheology were analyzed. The addition of 3 phr of GMA and 9 phr of NCC resulted in a significant increase in the tensile modulus of the PLA/PCL (75/25) blend from 1800 MPa (for neat PLA) to 3400 MPa. AFM analysis revealed that GMA improved the barrier properties of the PLA/PCL nanocomposite by reducing the roughness of the material. Furthermore, GMA and NCC promoted a higher degree of network formation within the polymer blend, as evidenced by a 4.5% increase in gel content. The incorporation of 9 phr of NCC increased the crystallinity of the PLA/PCL blend from 1.2% to 4.85%, although this effect was mitigated when GMA was also present. Interestingly, the simultaneous use of GMA and NCC significantly reduced the total migration of the material, resulting in a weight loss percentage of only 1.2%, compared to samples containing only one additive. Ultimately, the oxygen permeability of the compatibilized nanocomposite with 9 phr of NCC was measured at 60 ( cm 3 mm m 2 day atm) , a value comparable to that of commonly used oil-based polymers such as PE and PP. [ABSTRACT FROM AUTHOR]

This study explores the use of secondary gold tailings (SGTs) in concrete production to solve sand sustainability issues. This approach addresses waste issues and presents a sustainable material alternative to conventional sand, investigating different SGT proportions (ranging from 0% to 100%) to replace fine aggregate in structural concrete. This study examined the fresh, mechanical, and durability properties of concrete containing SGTs. Incorporating SGTs reduced the concrete's workability, but up to a 75% replacement level resulted in a high fresh concrete density compared with the reference concrete. The results indicated that up to 25% replacement level increased the compressive strength and up to 50% replacement level improved the splitting tensile strength compared with reference concrete. However, all concretes containing SGTs exhibited satisfactory strengths. The statistical analysis confirmed the significant influence of SGTs on concrete strength. In addition, the durability results of the concrete demonstrated good resistance to oxygen, water, and chloride penetration, indicating good concrete quality. SGTs are recommended as a substitute for crusher sand to reduce production costs, conserve natural resources, and promote a sustainable and greener environment. [ABSTRACT FROM AUTHOR]

Metal cans, while boasting excellent barrier properties, raise concerns about leaching and environmental impacts. This study explored plastic trays, a potential alternative for canned food packaging. First we delved into the plastic tray's characteristics, including its composition and permeability to oxygen and water vapor. Secondly, we conducted a comparison between the newly introduced plastic packaging and traditional metal cans, focusing on their interactions with food during the sterilization process and their effects on the quality of Tunisian pea sauce. The composition analysis revealed that the plastic tray was composed of polypropylene (PP) (with a single endothermic peak at 168 °C), while the film was found to have a mixture of PP internally and polyethylene terephthalate (PET) externally (with two endothermic peaks at 161.96 °C and 243.81 °C). Plastic trays showed good results in water vapor permeability (0.832 g/m2.d) but exhibited higher oxygen permeability (190 g/m2.d), raising oxidation concerns. Migration testing confirmed plastic packaging safety (<10 mg/dm2), while some simulants exceeded limits in metal cans. pH levels remained consistent between both packaging types, but varied significantly over a 28-day storage. Total Volatile Basic Nitrogen (TVBN) levels differed significantly between plastic and metal packaging, with notable variations observed over time with maximums of 0.3 mg/100 g for plastic trays and 0.17 mg/100 g for metal cans. Sensory evaluation revealed that tasters were adept at differentiating between canned pea sauce in plastic trays and metal cans (83%, 10/12), with taste and color exhibiting significant differences (p < 0.05). This underlines the impact of packaging material on canned food quality and consumer preference, with minimal influence on other sensory aspects. This data empowers manufacturers to make informed packaging decisions for a diverse range of canned foods. [ABSTRACT FROM AUTHOR]

This study focuses on developing compostable nanocomposite blown films, aiming to enhance oxygen barrier properties while maintaining good mechanical performance. Polybutylene succinate (PBS) and its blend with polylactic acid (PLA) were selected as matrices for the films. Organo‐montmorillonite Delite®43B (D43B) clay was incorporated to improve oxygen barrier, and random ethylene‐methyl acrylate‐glycidyl methacrylate terpolymer served as a plasticizer and reactive compatibilizer. Different blending sequences were examined to determine the optimal one that led to significant enhancements in both the barrier and mechanical properties of the final nanocomposite blown film. Various techniques, including SEM, TEM, XRD, DSC, oxygen permeability, and tensile testing were employed to characterize the morphology of the compounds and blown films. The results reveal greater oxygen barrier properties depending on the blending sequence. Indeed, a reduction in oxygen permeability exceeding 50% was observed following the addition of 3 wt% of D43B to the PBS/PLA film, selectively localized in the PLA phase. This enhancement further intensified after the addition of 5 wt% of the epoxy functionalized compatibilizer. Highlights: Enhancing PLA‐PBS compatibility with the epoxy functionalized compatibilizer led to a reduction in the final film's oxygen permeability.Achieving ideal ductility and barrier balance in films requires a synergistic blend of components: D43B, PLA, PBS, and compatibilizer.Optimizing balanced synergistic effects among compounds depends on the blending sequence method. [ABSTRACT FROM AUTHOR]

Soy protein isolate (SPI) and its mixture with other biopolymers, such as linear polysaccharides, have been considered as potential components to form biodegradable packaging. Films based on SPI (5% m/m film-forming solution) were prepared with the addition of sodium alginate (ALG) at different concentrations and pH values. The mechanical properties and oxygen permeability were studied and correlated with the crystallinity (X-ray), Fourier transform infrared (FT-IR) spectroscopy and the microstructure (scanning electron microscopy - SEM) of the films. The addition of ALG caused expressive changes in the structural arrangement of the SPI films, especially at pH 6 and 8. The FT-IR spectra of the films also showed the effects of the pH and ALG concentration on the relative intensity of the protein absorption bands, indicating stronger interaction between SPI and ALG at pH 11 than at pH 6 and 8. The resistance of the films was improved with the increasing addition of the polysaccharide, and with the highest alkalinity. Oxygen permeability evaluation of the films formed at pH 11 showed a significant decrease in permeability with increasing incorporation of ALG into the film matrix. The results indicate that the structure and the properties of the SPI-based films were modified and improved with ALG. It was concluded that alginate incorporation in SPI-based films with pH 11 improves mechanical and oxygen barrier properties. [ABSTRACT FROM AUTHOR]

The relationship between the characteristics of concrete pore structures and intrinsic permeability was investigated. The concrete pore structure incorporating fly ash was characterized by parameters including total porosity, pore size distribution (PSD), tortuosity, and characteristic pore sizes. The results indicate that: (1) there is a weak correlation between total porosity and critical pore size concerning oxygen permeability as interpreted by the Katz–Thompson model; (2) pores with diameters exceeding 100 nm serve as the primary tunnel for oxygen percolation in fly ash concrete; and (3) the porosity of pores larger than 100 nm and the average pore diameter exhibit the strongest correlation with oxygen permeability in fly ash concrete, as interpreted by the Katz–Thompson model. [ABSTRACT FROM AUTHOR]

Nanocomposites (NC) of polypropylene (PP) and organophilic montmorillonite (oMt) are produced by reactive mixing with simultaneous grafting of maleic anhydride (MA) onto PP using organic peroxide as initiator. Five different strategies of incorporating reactants and clay into a laboratory mixer are used. The structure of composites is examined by FT‐IR spectroscopy, x‐ray diffraction and scanning electron microscopy. Rotational rheometry, thermogravimetry and oxygen permeability are used to evaluate properties. The preparation method has a remarkable influence on NC's structure. Simultaneous addition of peroxide and MA to molten PP followed by incorporation of clay 20 minutes later produces the best degree of clay exfoliation/disaggregation. The NCs obtained using this procedure are highly transparent and have very thin tactoids with interlayer spacing more than 50% larger than the original oMt. The incorporation of just 2 wt% of clay gives place to more than 30% reduction in PP oxygen permeability. Additionally, the temperature at the maximum thermal degradation rate in nitrogen reduces in about 60°C while the temperature at which the thermal degradation process begins is not affected. Highlights: Highly intercalated/exfoliated PP/oMt nanocomposites are synthesizedReactive mixing procedure affects the quality of nanocomposite's structureA initial period of grafting before clay addition is the most effective methodHighly transparent materials with small tactoids of d001>4 nm is generatedPP oxygen permeability is highly reduced by the use of just 2 wt% of nanoclay [ABSTRACT FROM AUTHOR]

The plasma membrane forms the boundary between a living entity and its environment and acts as a barrier to permeation and flow of substances. Several computational means of calculating permeability have been implemented for molecular dynamics (MD) simulations-based approaches. Except for double bilayer systems, most permeability studies have been performed under equilibrium conditions, in large part due to the challenges associated with creating concentration gradients in simulations utilizing periodic boundary conditions. To enhance the scientific understanding of permeation and complement the existing computational means of characterizing membrane permeability, we developed a non-equilibrium method that enables the generation and maintenance of steady-state gradients in MD simulations. We utilize PBCs advantageously by imposing a directional bias to the motion of permeants so that their crossing of the boundary replenishes the gradient, like a previous study on ions. Under these conditions, a net flow of permeants across membranes may be observed to determine bulk permeability by a direct application of J = P Δ c . In the present study, we explore the results of its application to an exemplary O 2 and POPC bilayer system, demonstrating accurate and precise permeability measurements. In addition, we illustrate the impact of permeant concentration and the choice of thermostat on the permeability. Moreover, we demonstrate that energetics of permeation can be closely examined by the dissipation of the gradient across the membrane to gain nuanced insights into the thermodynamics of permeability. [ABSTRACT FROM AUTHOR]

This study focuses on mixed‐conducting perovskite membranes for efficient oxygen supply, aiming to replace energy‐intensive cryogenic distillation with a more practical alternative. A La and Nb co‐doped BaCoO3−δ perovskite is introduced, Ba0.95La0.05Co0.8Fe0.12Nb0.08O3−δ (BLCFN) with a record‐breaking oxygen permeation flux, surpassing all known single‐phase perovskite membranes. To elucidate its superior membrane performance, the mass/charge transport properties and equilibrium bulk properties are investigated and quantitative indicators (DO = 5.8 × 10−6 cm2 s−1, kO = 1.0 × 10−4 cm s−1, σion = 0.93 S cm−1 at 900 °C) reveal fast diffusion and excellent surface gas‐exchange kinetics. The oxygen permeability of 12.4 mL cm−2 min−1 and over 200 h of long‐term stability is achieved in an air/He atmosphere at 900 °C. By presenting a material that demonstrates higher performance than Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF), currently known for its highest permeability, it is believed that this marks a significant step toward innovative performance enhancement of perovskite oxide‐based membranes.

The main weakness of non-silicone hydrogel contact lenses is their low oxygen permeability (Dk). Hence, we have tried to optimize their Dk using various concentrations and lengths of the poly (ethylene glycol) dimethacrylate crosslinker in a mixture of N,N-Dimethylacrylamide and Cyclohexyl methacrylate monomers. After synthesizing the different contact lenses, we evaluated their chemical, optical, and mechanical properties. The resultant non-silicone hydrogel contact lenses presented similar high water contents (75.69–80.60%) and adequate optical (e.g., a transmittance ranging from 85.91% to 99.91% and a refractive index between 1.3630 and 1.3740) and elongation at break (178.95–356.05%) characteristics for clinical applications. Conversely, they presented high contact angles (81.00–100.00°) and a low Young’s modulus (0.066–0.167 MPa). Regarding the impact of the crosslinking modifications, the water content, contact angle, refractive index, transmittance, and Young’s modulus of the synthesized lenses were slightly affected by crosslinker conditions. In contrast, the elongation at break (178.95–356.05%) and, more importantly, the oxygen permeability, which reached values of up to 73.90 Fatt units, were considerably impacted by the crosslinker conditions. To our knowledge, this study demonstrates for the first time that, in addition to water, other usual hydrogel components, like crosslinkers, can modulate the Dk of non-silicone contact lenses. It also provides a simple and scalable method to fabricate more permeable non-silicone lenses.

Polylactide (PLA)‐based biodegradable three‐layer packaging film was fabricated using PLA, PLA/cinnamon oil (CEO), and PLA/graphene nanoplatelets (GNP). The central layer allows control over the release of antimicrobes, and the outer layer adds mechanical strength to the films. A comparison has been made on barrier, thermal, rheological, microstructural, and microbiological properties between single‐layer and multilayer films (MLF). The water vapor and oxygen barrier properties of MLF showed little reduction compared with those of neat PLA. The tensile stress of the neat PLA increased significantly from 23.31 to 35.91 MPa for the MLF. Thermal analysis data showed improvements in the thermal stability of the MLF film, with onset and peak temperatures of 331.5 and 357.1°C, respectively. The dispersion of GNP in the PLA matrix and in MLF was assessed by XRD analysis and rheological measurement. The AFM roughness parameters Sa and Sq of those films varied widely, with the highest (13.9 and 20.9 μm) and the lowest (0.08 and 0.11 μm) magnitudes recorded for PLA/GNP and PLA/CEO films, respectively. Antibacterial assays of the film confirmed a strong bactericidal effect against Listeria monocytogenes and Salmonella typhimurium, maintaining this activity for 21 days. Highlights: Polylactide/cinnamon oil/ graphene nanoplatelet multilayer films were coextruded.X‐ray diffraction and rheology confirm the dispersion of graphene into PLA.Tensile stress and thermal stability improved in the multilayer films.AFM roughness parameters varied significantly between single‐ and multilayer films.Antibacterial assays confirmed the strong bactericidal effect of films against pathogens. [ABSTRACT FROM AUTHOR]

Perovskite-like oxides based on lanthanum–strontium ferrites are considered to be promising electrode materials for use in various types of fuel cells, and the strategy of modifying these materials by partial substitution of iron with highly charged ferroactive cations has proved to be an efficient way to increase their chemical stability. In this work, the results of a study of the permeability of microtubular oxygen membranes based on La0.5Sr0.5Fe1 –xNbxO3 – δ are presented for the first time. The activation energy of oxide bulk diffusion was found (20 ± 4 kJ/mol). [ABSTRACT FROM AUTHOR]

Perovskite-like oxides based on lanthanum–strontium ferrites are considered to be promising electrode materials for use in various types of fuel cells, and the strategy of modifying these materials by partial substitution of iron with highly charged ferroactive cations has proved to be an efficient way to increase their chemical stability. In this work, the results of a study of the permeability of microtubular oxygen membranes based on La0.5Sr0.5Fe1 –xNbxO3 – δ are presented for the first time. The activation energy of oxide bulk diffusion was found (20 ± 4 kJ/mol). [ABSTRACT FROM AUTHOR]

Oxide-ion conductors have been widely used as catalytic, conductive, detecting and other materials under oxidizing, reducing, inert, mixed environments and the like. However, so far the evaluation of their oxygen-ion transport (such as oxide-ion conductivity and oxygen permeability) either is extrinsic or is limited only in oxidizing or inert environment. Herein, the evaluation of intrinsic oxygen-ion transport for oxide-ion conductors in all environments seems especially important. In this work, a new test system was designed to enable the oxide-ion conductors placing in single oxidizing, reducing, inert or mixed environment separately, which also realized all the oxygen-vacancy concentrations of oxide-ion conductors are in equilibrium in all environments. The intrinsic oxide-ion conductivity and oxygen permeability were evaluated in all environments, and the influencing factors regulated by environments also were analyzed to correlate the variation of oxygen-ion transport.

To suppress the oxidation loosening of HfB 2 -SiC coating, the HfB 2 was alloyed with HfSi 2 in the form of composite powders through self-propagating high-temperature synthesis (SHS) technique, which was then used to prepare HfB 2 -HfSi 2 -SiC coatings. Compared to the 60HfB 2 -SiC coating, the 60(HfB 2 -HfSi 2) SHS -SiC coating exhibited lower oxidation activity and better inert oxygen blocking at 1700 °C. The addition of HfSi 2 promoted the homogenization of the Hf-oxides distribution on the glass layer and the formation of the protective phase HfSiO 4 , further inhibiting oxygen diffusion. The 60(80HfB 2 -20HfSi 2) SHS -SiC coating exhibited optimal oxygen blocking protection after oxidation at 1700 °C, with 87.96% and 92.33% reductions in oxygen permeability and carbon loss rate, respectively. [ABSTRACT FROM AUTHOR]

The spent MoSi 2 modified ZrB 2 –SiC–MoSi 2 coatings were prepared on carbon matrixes by spark plasma sintering. A continuous metallurgical bonding was formed at the interface between the coating and matrix, and no obvious defects such as pores and cracks were observed inside. The effects of spent MoSi 2 content and trace doping in the spent powder on the oxidation behavior of the coatings in air at 1700 °C were investigated. During the active oxidation stage, the spent MoSi 2 promoted the densification of the coating and enhanced the structural oxygen barrier properties. With the increase of service time, during the inert oxidation stage, doping an appropriate amount of spent MoSi 2 helped to increase the fluidity of the rich-SiO 2 protective layer so that the Zr oxides fully dispersed in the generated Zr–B–Si–O–Al multiphase glass layer, which could impede the penetration of oxygen and enhance the oxidation protection efficiency. However, excessive spent MoSi 2 exacerbated the volatilization of gas by-products, forming pores and cracks in the glass layer and rising the oxidation loss. When the content of spent MoSi 2 was 20 vol%, the glass layer is dense and uniform, with few defects and the best oxygen resistance property. Moreover, compared with commercial powders, spent MoSi 2 contained Al 2 O 3 and SiO 2. Al 2 O 3 had an excellent modification effect, while SiO 2 glass can promote liquid phase sintering and seal the defects in the coatings. By adding spent MoSi 2 , the modified ZrB 2 –SiC–MoSi 2 composite coatings could inhibit the formation of defects and improve the dynamic stability of the coatings effectively. [ABSTRACT FROM AUTHOR]

Addition of copper oxide nanoparticles (CuONPs) to poly (butylene‐adipate‐co‐terephthalate) (PBAT)/thermoplastic starch (TPS) biopolymer blend produced bionanocomposite films with improved mechanical and oxygen barrier properties, as well as enhanced other benefits including antimicrobial activity. In this study, the PBAT/TPS‐CuO bionanocomposite films with varying CuONPs contents (0.05%, 0.5%, 1%, and 2%) were challenged by food simulants (10% ethanol represented to aqueous food and 3% acetic acid represented to acidic food) in accordance with European Regulation 10/2011. CuONPs in the bionanocomposite films demonstrated good stability when exposed to 10% ethanol; however, it was dissolved in 3% acetic acid. The X‐ray diffraction and the energy dispersive spectroscopy results showed that CuONPs in the film were completely lost after acid exposure, whereas CuONPs in the films exposed to 10% EtOH were preserved. The maximum overall migration value was 5.0 mg/dm2. Inductively coupled plasma optical emission spectroscopy was used to confirm the presence of Cu in the simulants. The highest soluble Cu value of 12.39 mg/kg was detected from PBAT/TPS‐CuO2%, while migration value decreased as concentration ratio in film decreased. Although both values were within the threshold limits established by current legislation for non‐specific migration limit substances in food contact materials, the properties of bionanocomposite were altered. The mechanical properties of a post‐migrated PBAT‐TPS/CuO films taken from acidic conditions were reduced by 22% in tensile strength and 53% in elongation at break due to holes and microcracks on the film surface observed by scanning electron microscope. The average sealing strength of all bionanocomposite films decreased by about 25% after acid exposure. The oxygen permeability, on the other hand, was significantly improved, with a 16.3% reduction. Because the film had lost all of its active agent, film was unable to inhibit Escherichia coli growth. While 3% acetic acid caused dissolution of CuONPs and significant changes in properties of PBAT/TPS‐CuO film, 10% ethanol caused very minor to no changes in bionanocomposite film properties. [ABSTRACT FROM AUTHOR]

The integration of platelet-shaped montmorillonite particles to improve the oxygen barrier of polyvinyl-alcohol-based barrier layers is state-of-the-art, but research on roll-to-roll coatings of such composite barrier lacquers has not been widely published. In this study, two different coating techniques, slot-die and reverse gravure, were used on a roll-to-roll scale to apply barrier lacquers comprising polyvinyl alcohol and montmorillonite. The lacquers were analyzed regarding viscosity at certain shear rates and surface energy and the dried coating layers regarding oxygen barrier, surface morphology, and particle orientation. Low permeability coefficients delivering a high oxygen barrier of 0.14 and 0.12 cm 3   (STP)   1   μ m m 2   d   bar   were achieved for the coating layers with slot-die and reverse gravure coating, respectively. It turned out that the properties of the barrier lacquer need to be adjusted to the coating technique to achieve high oxygen barrier performance. By tailoring the barrier lacquer formulation, the orientation of the platelet-shaped montmorillonite particles can be achieved using both techniques. A low solid content of down to 3   wt % is preferable for the premetered slot-die coating, because it results in low agglomeration quantity in the coating layer. A high solid content of up to 9   wt % is preferable for the self-metered reverse gravure coating to assure a homogeneously coated layer. [ABSTRACT FROM AUTHOR]

Fluorine free analogues of three commercially available rigid contact lens materials were prepared by replacing the fluorinated component, hexafluoroisopropyl methacrylate (HFPM), with the widely used, non-fluorinated monomers methyl methacrylate (MMA) and 3-methacryloxypropyltris-(trimethylsiloxy)silane (TRIS). The properties of the commercial materials and analogues were measured and compared. The oxygen permeabilities of the MMA analogues were found to be significantly lower than those of the commercial materials, decreasing by 87 % on average, while the TRIS analogues lacked sufficient hardness, dimensional stability and lipid deposit resistance to be viable for use in rigid contact lenses. Analogues prepared using a 1:1 mixture of MMA and TRIS had the best overall combination of properties, but were still on average 47 % less permeable to oxygen and also significantly less resistant to lipid deposition. The analogues prepared in this study did not adequately replicate the performance of marketed, fluorine containing rigid contact lens materials. These observations give an indication of the challenges that would face contact lens material manufacturers in preparing rigid lens polymers without the use of fluorinated species. A reduction in effectiveness would be almost inevitable, and would be expected to have a negative impact on the safety and eye health of rigid contact lens patients. [ABSTRACT FROM AUTHOR]

PLA (polylactic acid) is one of the three major biopolymers available on the market for food packaging, which is both bio-based and biodegradable. However, its performance as a barrier to gases remains too weak to be used for most types of food, particularly oxygen-sensitive foods. A surface treatment, such as coating, is a potential route for improving the barrier properties and/or providing bioactive properties such as antioxidants. Gelatin-based coating is a biodegradable and food-contact-friendly solution for improving PLA properties. The initial adhesion of gelatin to the film is successful, both over time and during production, however, the coating often delaminates. Corona processing (cold air plasma) is a new tool that requires low energy and no solvents or chemicals. It has been recently applied to the food industry to modify surface properties and has the potential to significantly improve gelatin crosslinking. The effect of this process on the functional properties of the coating, and the integrity of the incorporated active compounds were investigated. Two coatings have been studied, a control fish gelatin-glycerol, and an active one containing gallic acid (GA) as a natural antioxidant. Three powers of the corona process were applied on wet coatings. In the test conditions, there were no improvements in the gelatin crosslinking, but the corona did not cause any structural changes. However, when the corona and gallic acid were combined, the oxygen permeability was significantly reduced, while free radical scavenging, reduction, and chelating properties remained unaffected or slightly improved. [ABSTRACT FROM AUTHOR]

To inhibit the destructive evolution of the HfB2‐SiC coating during oxidation, La2O3 was added to modify the oxygen‐blocking capability of the HfB2‐SiC coating. The effect of La2O3 content on the oxygen barrier capacity of HfB2‐SiC was investigated. The addition of 5 vol.% La2O3 lowered the oxidation activity and strengthened the inert oxygen barrier capacity of the HfB2‐SiC coating, which made the oxygen permeability and maximum weight change rate of the coating decrease by 30.32% and 73.97%, respectively. Due to the solid solution reaction of the dispersed La2O3, HfO2, and SiO2 nanoparticles, a stable Hf‐B‐La‐Si‐O multiphase glass was formed on the surface of the coating. Besides, the high‐melting‐point particles, such as HfO2, La2Hf2O7, and HfSiO4, dispersed in the glass layer as hard particles and formed a mosaic structure based on the Hf‐B‐La‐Si‐O compound, which increased the cumulative protection efficiency of the HfB2‐SiC coating to 98.5% and reduced the inert factor value by 84.57%. However, the excessive consumption of SiO2 glass by La2O3 results in dendritization of the generated glass when the La2O3 content is above 10 vol.%, which reduced the self‐healing capability of the generated glass and instead weakened the oxygen barrier properties of the HfB2‐SiC‐La2O3 coatings. [ABSTRACT FROM AUTHOR]

Polyamide 6 (PA6) and PA6/ethylene vinyl alcohol copolymer (EVOH) films were prepared through extrusion casting process, followed by uniaxial and biaxial stretching on a laboratory biaxial stretcher. The crystallization properties, mechanical properties, and barrier properties of PA6/EVOH films before/after stretching were investigated. It is found that the crystallinity of the stretched PA6/EVOH film is increased with the increase in EVOH content and stretching ratio. Notably, the oxygen barrier property of biaxially stretched PA6/EVOH films is 3 times higher than that of neat PA6 due to the strong interaction of two polymers and increased crystallinity. The modulus, tensile strength, and elongation at break of biaxially stretched PA6 films are also enhanced with the incorporation of EVOH. The crystal orientation of stretched PA6/EVOH films was investigated according to the wide-angle X-ray scattering analysis. The degree of orientation is increased with the stretching ratio. With the increase in the orientation degree, the stretched films show increased tensile strength whereas decreased toughness. Furthermore, the biaxially stretched films present balanced mechanical properties, and the stretching ratio of 3 × 3 shows excellent comprehensive mechanical properties. [ABSTRACT FROM AUTHOR]

Recently, packaging industry has turned to biodegradable packaging, and poly(lactic acid) has become the most remarkable polymer. However, the high oxygen permeability of PLA films significantly limits their use. Therefore, this study, it was aimed to improve the oxygen barrier properties of PLA films without adversely affecting the mechanical and water vapor barrier properties. Biodegradable PLA-Zein bi-layer films were produced by changing PLA and zein thickness. Transparent and UV barrier bi-layer films were obtained. Mechanical properties of PLA films were improved by the production of bi-layer films. Water vapor permeability of bi-layer films increased whereas the permeance decreased with zein coating of PLA. Multi-criteria decision hierarchy was used to select the best bi-layer films based on mechanical, permeance, and opacity results. Oxygen barrier properties of PLA film significantly improved by zein coating, and hydrophobicity of PLA film was not affected by zein coating. The crystallization and melting temperatures of films decreased when compared to PLA films, supporting the mechanical results. Homogeneous, non-porous, and smooth film surface was obtained and zein layer was in good compatibility with PLA layer. These results suggest that zein coatings could be used to decrease oxygen permeability of PLA films without negatively affecting other properties. • Biodegradable bi-layer films were produced from PLA and zein. • PLA was used as first layer, while zein films were second layer. • Mechanical properties of neat PLA films were improved by zein coating. • Oxygen permeability of neat PLA film was significantly decreased by zein coating. • PLA-zein bi-layer films can be useful with high oxygen barrier properties in food packaging. [ABSTRACT FROM AUTHOR]

• High water content and oxygen permeability of silicone hydrogels were prepared. • Incorporation of carboxylic groups increase water content. • Water content varies with freeable free water and bound water. • Surfactant incorporation improves the connectivity of the silicone network. • Oxygen permeability and water content reach 100.4 barrer and 58.4 %, respectively. Silicone hydrogels are vital materials in fields like contact lenses, biomedicine, and electronic devices, prized for their unique properties including oxygen permeability and equilibrium water content (EWC). These features make them ideal for applications that require both breathability and moisture retention, enhancing their performance and comfort in various uses. Typically, enhancing the silicone content increases oxygen permeability but reduces EWC, creating a significant trade-off. This study introduces an innovative approach using carboxylic acid and surfactant to address this challenge. The addition of carboxylic acid markedly boosts the EWC by increasing both freezable free water and bound water. Simultaneously, the surfactant enhances the connectivity within the silicone structure, mitigating the reduction in oxygen permeability and improving the material's ductility, which is often compromised by water absorption that restricts the motion of the silicone chains. With these modifications, the silicone hydrogel achieves approximately 97 % transmittance at 550 nm, with oxygen permeability reaching 100.4 barrer and EWC at 58.4 %, representing improvements of 11.3 % and 61.3 %, respectively, compared to the original material. These results exceed many of the enhancements in silicone hydrogels previously reported in the literature. [Display omitted] [ABSTRACT FROM AUTHOR]

• Hydroxyethyl lignin derivatives used for direct esterification of technical lignin. • Lignin cinnamate derivatives were melt-processable forming blends with PBAT. • Mechanical properties, oxygen barrier, WVTR, and antioxidant properties improved. • Shelf life of fresh fruit was enhanced by the presence of lignin cinnamates in PBAT packaging. In this study, a two-step chemical modification method was applied to lignin, enabling the thermal blending of lignin and Ecoflex® (PBAT) to produce films for food packaging applications. In the first step, 90 % of phenolic and carboxylic acid groups were converted into aliphatic hydroxy groups via hydroxyethylation, and in the second step, the aliphatic hydroxy groups were esterified with cinnamic acid, introducing abundant phenyl rings as well as unsaturated groups to the polymer. The modified lignin possessed an aliphatic–aromatic structure, similar to Ecoflex®, thereby enhancing the potential miscibility between these two materials. Subsequent experiments revealed that adding 20 % of modified lignin into Ecoflex® film resulted in the most significant improvement in mechanical properties, tripling the stiffness and doubling the strength. The addition of 30 % of modified lignin showed the best outcomes in UV absorption, barrier properties against oxygen and water vapor, and anti-oxidation ability. A strawberry ripening test indicated that the Ecoflex® film containing 30 % of modified lignin extended the shelf-life of strawberries from 2 days to 7 days, with better performance than the results of polyethylene bags and pure Ecoflex® films. [ABSTRACT FROM AUTHOR]

Ceramic oxygen transport hollow fiber La 0.4 Sr 0.6 Fe 0.95 Mo 0.05 O 3-δ (LSFM5) membranes were fabricated via combined phase inversion and sintering technique. High-temperature X-ray diffraction experiments indicated that LSFM5 oxide undergoes second order phase transition at temperature above 300 °C from rhombohedral to cubic structure. The inner and outer surfaces of LSFM5 membranes were modified by acid etching and by depositing a surface decoration layer. For both kinds of membranes with modified surfaces, the enhancement of oxygen fluxes was observed at operating temperature range 860–980 °C, which indicates that the surface oxygen exchange reactions play a decisive role in the control of the oxygen transport. Catalytic experiments of methane partial oxidation (POM) by Ni/LSFM5 based oxygen-permeable membrane reactor exhibited good performance both in the mode with synthetic air on the supply side, and in the mode of POM coupled with CO 2 splitting on the supply side. • LSFM5 oxide undergoes second order phase transition. • LSFM5 HF membranes with unique wall structure were fabricated by phase inversion technique. • The effect of surface modification on membrane performance was studied. • CO 2 splitting and partial oxidation of CH 4 was coupled in catalytic Ni/LSFM5 membrane reactor. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) were produced from bleached eucalyptus kraft pulp using microfluidization varying the number of passes through the microfluidizer. CNFs were processed into dry films to elucidate the effect of CNFs morphology on the physical, optical and barrier properties of the films. As the number of passes through the microfluidizer increased, the fibril diameter and degree of polymerization decreased. A higher number of passes produced CNFs with smaller diameter resulting in CNF films with smaller root mean surface (RMS) roughness, higher tensile strength and Young's modulus, and higher transparency. CNF films with lower porosity had lower water vapor permeability (WVP) at 50% RH (better barrier properties), but the number of passes did not significantly affect water vapor permeability at 90% RH or oxygen permeability at 50% RH or 90% RH. Increasing the number of microfluidization passes resulted in CNF films with higher density, lower crystallinity, and higher water accessibility. The results suggest that the physical properties, such as density, of the film were more dominant for the mechanism of WVP compared with crystallinity and water accessibility. A model of water vapor transmission through the CNF film was proposed. By establishing a relationship between CNFs morphology and performance characteristics of corresponding films, especially for barrier properties, insights were obtained that would be beneficial for food packaging applications.

For proton exchange membrane fuel cells to be cost‐competitive in light‐ and heavy‐duty vehicle applications, their Pt content in the catalyst layers needs to be lowered. However, lowering the Pt content results in voltage losses due to high local oxygen transport resistances at the ionomer–Pt interface. It is therefore crucial to use ionomers that have higher oxygen permeability than Nafion. In this work, novel high oxygen permeability ionomers (HOPIs) are presented, with up to five times higher oxygen permeability than Nafion, synthesized by copolymerization of perfluoro‐2,2‐dimethyl‐1,3‐dioxole (PDD) with perfluoro(4‐methyl‐3,6‐dioxaoct‐7‐ene) sulfonyl fluoride (PFSVE). PDD is the source of higher permeability due to its open ring structure, while PFSVE provides ionic conductivity. Optimization of PDD content and equivalent weight enables increased fuel cell performance, mainly at high current densities, where HOPIs can achieve power densities >1.25 W cm−2 and exceed the 0.8 A cm−2 U.S. Department of Energy durability target by losing only 4.5 mV, which is over six times less than 30 mV. The interactions between HOPI and SO3− groups with a PtCo/C catalyst are also elucidated here at a fundamental level. [ABSTRACT FROM AUTHOR]

Polyacrylate coating has been used for modifying Polyethylene terephthalate (PET) film to improve its oxygen barrier performance. However, comprehensive study on the oxygen barrier of polyacrylate coating is still underway. In this work, a series of polyacrylate coatings with different functional monomers such as maleic acid (MA), acrylic acid (AA), 2-hydroxyethyl acrylate (2-HEA), and 2-butene-1, 4-diol (1, 4-BED) were prepared by using Desmodur L75 (L75) and Erisys Ga240 (Ga240) as a curing agent. The polyacrylate coatings were characterized by Fourier Transform Infrared (FT-IR) spectrometer. The oxygen permeability (Po2) of the coatings was measured by Gas Permeability Tester. The results reveal that anhydride moiety produced by dehydration of carboxylic acid is the key structure for enhancing the oxygen barrier property of the polyacrylate coating. Moreover, when the anhydride coexists with other cross-linking structures, the oxygen barrier performance of the resulting coatings was not further enhanced. Compared with the pristine PET substrate, the anhydride-containing polyacrylate-coated PET film has reduced Po2 by 68%. This work provides a facile strategy for improving the oxygen barrier performance of PET film by coating amorphous polyacrylate. [ABSTRACT FROM AUTHOR]

Fully conjugated polyazomethines (PAZs) exhibit large amounts of micropores among their many short branches in relatively planar structures based on their fully conjugated configuration. However, these fully conjugated structures cause insolubility and non‐processability of the PAZs because they may have strong stacking interactions due to their planar structures. In this paper, to overcome this problem, three short lengths of oligodimethylsiloxane (ODMS) grafts (x = 9, 18 and 39) were introduced by end‐capping reaction of aldehydes at the end of insoluble PAZs with amino‐terminated ODMSs as end‐capping agents. As a result, the insoluble PAZs became almost soluble (solubility > 95–100%) and their molecular weight could be estimated using gel permeation chromatography (Mw = 15.9 × 103 g mol−1). PAZ‐embedded mixed‐matrix membranes (MMMs) were fabricated using blend solutions containing only small amounts (1.0 wt%) of the solubilized PAZs with ODMS grafts and crosslinked polydimethylsiloxane (PDMS). The PAZs/PDMS MMMs showed ultrahigh permeability to oxygen which achieved 8600 barrer without a decrease of the original permselectivity of PDMS. The excellent oxygen permeability of the PAZs/PDMS MMMs may be caused by an effective increase of porosity based on the fully conjugated PAZ nanosheet. © 2022 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

This research was conducted for the synthesis and application of ophthalmic lens materials with improved oxygen permeability and durability. Polyvinylpyrrolidone (PVP), N-vinyl-2-pyrrolidone (NVP), 3-(trifluoromethyl)styrene (3-TFMSt), and magnesium oxide nanoparticles were used as additives for the basic combination of 2-hydroxyethyl methacrylate (HEMA). Additionally, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent and azobisisobutyronitrile (AIBN) as the initiator. The addition of magnesium oxide nanoparticles was found to increase the tensile strength from 0.0631 to 0.0842 kgf/mm2. Copolymerization with a small amount of 3-TFMSt of about 1% increased the tensile strength to 0.1506 kgf/mm2 and the oxygen permeability from 6.00 to 9.64 (cm2/s)∙(mLO2/mL·mmHg)∙10−11. The contact lens material produced using N-vinyl-2-pyrrolidone and magnesium oxide nanoparticles as additives satisfied the basic physical properties required for hydrogel contact lenses and is expected to be used usefully as a material for fabricating high-performance hydrogel lenses. [ABSTRACT FROM AUTHOR]

Intrinsically stretchable organic electrochemical transistors (OECTs) are being pursued as the next‐generation tissue‐like bioelectronic technologies to improve the interfacing with the soft human body. However, the performance of current intrinsically stretchable OECTs is far inferior to their rigid counterparts. In this work, for the first time, the authors report intrinsically stretchable OECTs with overall performance benchmarkable to conventional rigid devices. In particular, oxygen level in the stretchable substrate is revealed to have a significant impact on the on/off ratio. By employing stretchable substrates with low oxygen permeabilities, the on/off ratio is elevated from ≈10 to a record‐high value of ≈104, which is on par with a rigid OECT. The device remained functional after cyclic stretching tests. This work demonstrates that intrinsically stretchable OECTs have the potential to serve as a new building block for emerging soft bioelectronic applications such as electronic skin, soft implantables, and soft neuromorphic computing. [ABSTRACT FROM AUTHOR]

Internal oxidation of Fe–2.25Cr has been studied in Fe/FeO Rhines pack (RP) and H2/H2O gas mixtures at 700–900 °C. A novel exposure technique allowing RP experiments in dual atmosphere conditions was developed. No measurable effect of hydrogen on lattice oxygen permeability in ferrite could be detected: neither in single nor in dual atmosphere conditions. The H2/H2O atmosphere was found to induce stronger oxidation attack at alloy grain boundaries resulting in a morphology similar to intergranular stress corrosion cracking often reported in nuclear technology. The intergranular oxidation attack was demonstrated to be independent of the dual atmosphere effect, i.e., hydrogen dissolved in the alloy. [ABSTRACT FROM AUTHOR]

To suppress the oxidation of TaB 2 -SiC coatings, the effects of pre-oxidation temperature on the oxygen hindering properties of TaB 2 -SiC coatings were investigated to prepare TaB 2 -SiC coatings with enhanced oxidation behavior. The addition of 40 wt% TaB 2 made the oxygen permeability of the coating decrease by 62.16%. However, excessive TaB 2 weakened the oxygen hindering ability of the coating due to the large ion complex ability of Ta5+. The pre-oxidation temperature at 1500 °C led to a homogeneous dispersion of Ta-oxide nanocrystal particles in the Ta-B-Si-O complex-phase glass layer. In contrast with the untreated samples, the active factor and inert factor values of the TaB 2 -SiC coating after pre-oxidation treatment at 1500 °C decreased by 43.12% and 17.33%, respectively, which improved the dynamic stability of the coating during oxidation. [ABSTRACT FROM AUTHOR]

Abstract Intrinsically stretchable organic electrochemical transistors (OECTs) are being pursued as the next‐generation tissue‐like bioelectronic technologies to improve the interfacing with the soft human body. However, the performance of current intrinsically stretchable OECTs is far inferior to their rigid counterparts. In this work, for the first time, the authors report intrinsically stretchable OECTs with overall performance benchmarkable to conventional rigid devices. In particular, oxygen level in the stretchable substrate is revealed to have a significant impact on the on/off ratio. By employing stretchable substrates with low oxygen permeabilities, the on/off ratio is elevated from ≈10 to a record‐high value of ≈104, which is on par with a rigid OECT. The device remained functional after cyclic stretching tests. This work demonstrates that intrinsically stretchable OECTs have the potential to serve as a new building block for emerging soft bioelectronic applications such as electronic skin, soft implantables, and soft neuromorphic computing.

To heighten the oxidation inhibition capacity of HfB 2 -SiC coating, film-forming regulation of the self-formed compound layer was utilized to enhance the dynamic stability and the oxygen hindering capacity of the coating. The oxidation process of the HfB 2 -SiC coating in air from room temperature to 1700 °C can be divided into the lower temperature oxidation zone, the medium temperature protection zone and the high temperature corrosion zone. The oxidation activity of the coatings was significantly weakened in the medium temperature oxidation protection zone from 1100 °C to 1400 °C, which was selected as the film-forming regulation temperature region to ensure the lower film-forming wastage of the coatings. When the film-forming temperature was 1200 °C, the coating was uniformly covered by the glass layer with fewer defects. The values of active factor and inerting factor of the HfB 2 -SiC coating after film-forming at 1200 °C were 0.151 and 0.953 × 10−6 g cm−2 s−1, respectively, which show the lowest film-forming wastage of the coating. With further ascending the film-forming temperature, a large number of pores and cracks generated on the glass layer owing to the evaporation and release of the gaseous byproducts, which destroyed the structure of the glass layer and aggravated the oxidation wastage of the coating. With increasing the film-forming time at 1200 °C for 360 min, the protection efficiency of the HfB 2 -SiC coating increased to 99.13%, the oxygen permeability and carbon loss rate decreased by 79.6% and 67.8%, respectively, which slowed down the oxidation activity and improved the dynamic stability of the coating during oxidation. [ABSTRACT FROM AUTHOR]

The characteristics of microtubular oxygen-permeable membranes fabricated with the use of a new method of low-temperature phase inversion are shown. As the membrane material, a modification of the well-known La0.6Sr0.4Co0.2Fe0.8O3 – δ composite doped with Mo cations at B site (Mo+6 = 0.05) is studied for the first time. [ABSTRACT FROM AUTHOR]

The membrane-based electrolysis of water is a growing topic of interest due to the advantages of employing membranes in hydrogen production efficiency and system safety over the traditional alkaline water electrolysis. Ion-exchange membranes with low gas permeability are highly desirable for stable and safe operation of membrane-based water-splitting technologies, hence gas permeability through ion-exchange membranes needs to be properly assessed with standardized methods. We addressed three methods to measure gas permeability of ion-exchange membranes, a pressure permeation cell, chronoamperometry microelectrodes, and in situ testing of the membrane electrode assembly, and provide a guideline for choosing the appropriate method for the targeted operating conditions of the water electrolyzers.

Simultaneous syngas and pure hydrogen production through partial oxidation of methane and water splitting, respectively, were demonstrated by using mixed ionic–electronic conductors. Tubular ceramic membranes prepared from La0.5Sr0.5FeO3 perovskite were successfully utilized in a 10 M lab scale reactor by applying a radial arrangement. The supply of methane to the middle area of the reaction zone was shown to provide a uniform distribution of the chemical load along the tubes’ length. A steady flow of steam feeding the inner part of the membranes was used as oxidative media. A described configuration was found to be favorable to maintaining oxygen permeability values exceeding 1.1 mL∙cm–2∙min–1 and long-term stability of related functional characteristics. Methane’s partial oxidation reaction assisted by 10%Ni@Al2O3 catalyst proceeded with selectivity values above 90% and conversion of almost 100%. The transition from a laboratory model of a reactor operating on one tubular membrane to a ten-tube one resulted in no losses in the specific performance. The optimized supply of gaseous fuel opens up the possibility of scaling up the reaction zone and creating a promising prototype of a multitubular reaction zone with a simplified sealing procedure.

Canola protein obtained from canola meal, a byproduct of the canola industry, is an economical biopolymer with promising film-forming properties. It has significant potential for use as a food packaging material, though it possesses some functional limitations that need improvement. Incorporating nanomaterials is an option to enhance functional properties. This study aims to produce canola protein films by integrating GO exfoliated at several oxidation times and weight ratios to optimize mechanical, thermal, and barrier properties. Oxidation alters the C/O ratio and adds functional groups that bond with the amino/carboxyl groups of protein, enhancing the film properties. Significant improvement was obtained in GO at 60 and 120 min oxidation time and 3% addition level. Tensile strength and elastic modulus increased 200% and 481.72%, respectively, compared to control. Control films showed a 37.57 × 10−3 cm3m/m2/day/Pa oxygen permeability, and it was significantly reduced to 5.65 × 10−3 cm3m/m2/day/Pa representing a 665% reduction. [Display omitted] • Oxygen functional groups were created by oxidizing graphite oxide. • Tensile strength and elongation at break percentage improved with graphite oxide. • Adding graphite oxide with 60 min or more oxidation reduced water vapor permeability. • Oxygen permeability was reduced by 665% when graphite oxide was oxidized to 120 min. • Thermal stability was improved by adding graphite oxide with more oxidation time. [ABSTRACT FROM AUTHOR]

PLA (polylactic acid) is one of the three major biopolymers available on the market for food packaging, which is both bio-based and biodegradable. However, its performance as a barrier to gases remains too weak to be used for most types of food, particularly oxygen-sensitive foods. A surface treatment, such as coating, is a potential route for improving the barrier properties and/or providing bioactive properties such as antioxidants. Gelatin-based coating is a biodegradable and food-contact-friendly solution for improving PLA properties. The initial adhesion of gelatin to the film is successful, both over time and during production, however, the coating often delaminates. Corona processing (cold air plasma) is a new tool that requires low energy and no solvents or chemicals. It has been recently applied to the food industry to modify surface properties and has the potential to significantly improve gelatin crosslinking. The effect of this process on the functional properties of the coating, and the integrity of the incorporated active compounds were investigated. Two coatings have been studied, a control fish gelatin-glycerol, and an active one containing gallic acid (GA) as a natural antioxidant. Three powers of the corona process were applied on wet coatings. In the test conditions, there were no improvements in the gelatin crosslinking, but the corona did not cause any structural changes. However, when the corona and gallic acid were combined, the oxygen permeability was significantly reduced, while free radical scavenging, reduction, and chelating properties remained unaffected or slightly improved.