Academic literature on the topic 'Oxygen barrier propertie'
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Journal articles on the topic "Oxygen barrier propertie"
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Schmid, Markus, Kerstin Dallmann, Elodie Bugnicourt, Dario Cordoni, Florian Wild, Andrea Lazzeri, and Klaus Noller. "Properties of Whey-Protein-Coated Films and Laminates as Novel Recyclable Food Packaging Materials with Excellent Barrier Properties." International Journal of Polymer Science 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/562381.
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In case of food packaging applications, high oxygen and water vapour barriers are the prerequisite conditions for preserving the quality of the products throughout their whole lifecycle. Currently available polymers and/or biopolymer films are mostly used in combination with barrier materials derived from oil based plastics or aluminium to enhance their low barrier properties. In order to replace these non-renewable materials, current research efforts are focused on the development of sustainable coatings, while maintaining the functional properties of the resulting packaging materials. This article provides an introduction to food packaging requirements, highlights prior art on the use of whey-based coatings for their barriers properties, and describes the key properties of an innovative packaging multilayer material that includes a whey-based layer. The developed whey protein formulations had excellent barrier properties almost comparable to the ethylene vinyl alcohol copolymers (EVOH) barrier layer conventionally used in food packaging composites, with an oxygen barrier (OTR) of <2 [cm³(STP)/(m²d bar)] when normalized to a thickness of 100 μm. Further requirements of the barrier layer are good adhesion to the substrate and sufficient flexibility to withstand mechanical load while preventing delamination and/or brittle fracture. Whey-protein-based coatings have successfully met these functional and mechanical requirements.
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SATAM, CHINMAY, ASHOK GHOSH, and PETER W. HART. "Commercially relevant water vapor barrier properties of high amylose starch acetates: Fact or fiction?" September 2021 20, no. 9 (October 1, 2021): 599–604. http://dx.doi.org/10.32964/tj20.9.599.
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Starches have recently regained attention as ecofriendly barrier materials due to the increased demand for sustainable packaging. They are easily processable by conventional plastics processing equipment and have been utilized for oil and grease barrier applications. While starches have excellent oxygen barrier properties and decent water barrier properties at low relative humidity (RH), they are moisture sensitive, as demonstrated by the deterioration of the barrier properties at higher RH values. Starch esters are chemically modified starches where the hydroxyl group of the starch has been substituted by other moieties such as acetates. This imparts hydrophobicity to starches and has been claimed as a good way of retaining water vapor barrier properties of starches, even at high RH conditions. We studied the water vapor barrier properties of one class of starch esters, i.e., high amylose starch acetates that were assumed to have good water vapor barrier properties. Our investigations found that with a high degree of substitution of hydroxyl groups, the modified starches did indeed show improvements in water vapor response as compared to pure high amylose starch films; however, the barrier properties were orders of magnitude lower than commercially used water vapor barriers like polyethylene. Even though these materials had improved water vapor barrier response, high amylose starch acetates are likely unsuitable as water vapor barriers by themselves, as implied by previous literature studies and patents.
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Ahmadi, Zahed. "Interfacial interaction exploration and oxygen barrier potential of polyethylene/poly(ethylene-co-vinyl alcohol)/clay hybrid nanocomposites." e-Polymers 17, no. 2 (March 1, 2017): 175–85. http://dx.doi.org/10.1515/epoly-2016-0240.
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AbstractHybrid nanocomposites based on high-density polyethylene (HDPE)/poly (ethylene-co-vinyl alcohol) (EVOH)/clay were prepared and fully characterized. Morphological (WAXS and TEM), calorimetric (DSC), and dynamic mechanical thermal (DMTA) analyses were applied to investigate potential of nanocomposites as barrier against oxygen. Co-existence of ingredients of different nature, i.e. HDPE (general-purpose non-polar component), EVOH (engineering polar component with excellent barrier properties), nanoclay (planar one-dimensional mineral barrier nanofiller), and maleated HDPE (PE-g-MA) as coupling agent, brings about serious intricacies in view of interaction between existing phases. Conceptual/experimental analysis was performed to explore the interdependence between microstructure and oxygen barrierity of HDPE/EVOH/clay nanocomposites through the lens of interaction state in the system. Morphological measurements confirmed formation of an intercalated nanostructure, while investigations on complex viscosity, storage modulus, permeability, thermo-mechanical properties, and nanoclay interlayer galleries were all indicative of dependence of nanocomposites’ properties on molecular interactions. The performance of nanocomposite sheets as oxygen barriers was mechanistically explained.
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Mulroue, J., and D. M. Duffy. "An ab initio study of the effect of charge localization on oxygen defect formation and migration energies in magnesium oxide." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 467, no. 2131 (March 16, 2011): 2054–65. http://dx.doi.org/10.1098/rspa.2010.0517.
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Plane-wave density functional theory was used to study the properties of oxygen vacancies and interstitials, with different charge states, in MgO. The calculated properties were the relaxed configurations, the Frenkel defect formation energies and the energies of the migration barriers, and all properties were found to be strongly dependent on the defect charge state. The lowest energy configuration of the O 2− interstitial was found to be the cube centre; however, the O − and O 0 interstitials formed dumb-bell configurations. The Frenkel defect energies were also strongly dependent on the defect charge, with the neutral pair energy calculated to be 3 eV lower than the doubly charged Frenkel pair defect energy. The migration barriers of the oxygen vacancies were found to increase as the net charge of the oxygen vacancies decreased, which suggests that vacancies with trapped electrons are much less mobile than the F 2+ vacancies modelled by classical potentials. The migration of the oxygen interstitials showed particularly interesting behaviour. The O 0 interstitial was found to have a higher migration barrier than the O 2− interstitial but a very low barrier (0.06 eV) was found for the O − interstitial. The results have significant implications for the reliability of classical radiation damage simulations.
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Bakker, Sterre, Joey Kloos, Gerald A. Metselaar, A. Catarina C. Esteves, and Albert P. H. J. Schenning. "About Gas Barrier Performance and Recyclability of Waterborne Coatings on Paperboard." Coatings 12, no. 12 (November 28, 2022): 1841. http://dx.doi.org/10.3390/coatings12121841.
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For preserving food packed in environmentally friendly and recyclable paperboard packages, it is important to have sufficient gas barrier performance of the paperboard container. Paperboard has poor intrinsic barrier properties and to overcome this deficiency, so a barrier coating is needed that does not hinder the recycling of the paperboard substrate. However, the gas barrier properties and the recyclability of such coatings have been rarely studied. Here, both the gas barrier performance and the removal of an alkali-soluble resin (ASR)-stabilized waterborne barrier coatings from paperboard are investigated. For barriers for gases, such as nitrogen, carbon dioxide, and oxygen, defect-free coatings are needed which is achieved by applying three coating layers. The oxygen transmission rate (OTR) of the three-layered coating on paperboard was 920 cm3/(m2∙day). For water vapor barriers, two coating layers already show a strong improvement, as water follows a different penetration mechanism than the other tested gases. The water vapor transmission rate WVTR of double coated paperboard was 240 g/(m2∙day). Preliminary results show that the coating is removed by immersion of the coated paperboard in an aqueous alkaline solution at room temperature. This causes de-protonation of the carboxylic acids of the ASR and subsequent re-dispersion of the coating in water. Removing double-layer coatings from the paperboard is more challenging, possibly due to the coating/coating interface between the two coating layers and enhanced adhesion between coating and paperboard.
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Liu, R. Y. F., D. A. Schiraldi, A. Hiltner, and E. Baer. "Oxygen-barrier properties of cold-drawn polyesters." Journal of Polymer Science Part B: Polymer Physics 40, no. 9 (March 28, 2002): 862–77. http://dx.doi.org/10.1002/polb.10149.
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Ayuso, Carmen Fernández, Alejandro Arribas Agüero, Jose A. Plaza Hernández, Antonio Bódalo Santoyo, and Elisa Gómez Gómez. "High Oxygen Barrier Polyethylene Films." Polymers and Polymer Composites 25, no. 8 (October 2017): 571–82. http://dx.doi.org/10.1177/096739111702500802.
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“Layer by layer” technology was used to create transparent, thin and high barrier polyethylene films to use in food packaging. These films were made by inserting successive layers of polyacrylamide and montmorillonite (Cloisite Na+, non-organic modification) grown onto a low density polyethylene (LDPE) film substrate submitted to corona treatment. Excellent oxygen permeability results were reached with only 9 bilayers, with a reduction of 99.92%, compared to the pure polyethylene. This allowed the oxygen barrier film to change from poor to high (3.66 cm3/m2·day), with a total thickness of 48 microns, due to the structure formed over the film to create a tortuous path for oxygen molecules. Optical properties were analysed, showing a ≥92% transparency in all samples. Thermal stability of polyethylene was slightly improved and this was attributed to nanoclays presence forming an insulating layer. The result of this research is a thin structured film which is a good candidate for common barrier films replacement in food packaging thanks to its high oxygen barrier capacity, optical transparency, microwaveability and recyclability.
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Sardon, H., A. González, M. J. Fernández-Berridi, and L. Irusta. "Oxygen Barrier Properties of Waterborne Polyurethane/Silica Hybrids." Journal of Macromolecular Science, Part B 54, no. 6 (April 6, 2015): 711–21. http://dx.doi.org/10.1080/00222348.2015.1035613.
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Holsti-Miettinen, R. M., K. P. Perttilä, J. V. Seppälä, and M. T. Heino. "Oxygen barrier properties of polypropylene/polyamide 6 blends." Journal of Applied Polymer Science 58, no. 9 (November 28, 1995): 1551–60. http://dx.doi.org/10.1002/app.1995.070580918.
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Xie, Pengkang, Ziyue Wang, and Kangning Wu. "Evolution of Intrinsic and Extrinsic Electron Traps at Grain Boundary during Sintering ZnO Based Varistor Ceramics." Materials 15, no. 3 (January 30, 2022): 1098. http://dx.doi.org/10.3390/ma15031098.
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In this paper, evolution of microstructures, electrical properties and defects of the double Schottky barrier during the sintering process were investigated by quenching ZnO varistor ceramics at different sintering stages. It was found that morphology of the samples changed little when the temperature was below 800 °C. Remarkable enhancement of the Schottky barrier height and electrical properties took place in the temperature range between 600 °C and 800 °C. The Bi-rich intergranular layer changed from β phase to α phase. The interfacial relaxation at depletion/intergranular layers became detectable in the samples. Meanwhile, a distinct relaxation loss peak from electron trapping of interface states was observed instead of two dispersed ones. It indicated that the differences among the Schottky barriers in ZnO varistor ceramics became smaller with the process of sintering, which was also supported by the admittance spectra. In addition, oxygen vacancy was found more sensitive to the sintering process than zinc interstitial. The results could provide guidance for fine manipulating the Schottky barrier and its underlying defect structures by optimizing sintering process.
Dissertations / Theses on the topic "Oxygen barrier propertie"
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FOTIE, GHISLAIN. "EFFECTIVE REPLACEMENT IN FOOD PACKAGING OF OIL-BASED OXYGEN-BARRIER POLYMERS (EVOH, PVDC), WITH BIO-COMPOSITES CONTAINING CELLULOSE NANOCRYSTALS (CNCS) EXTRACTED FROM WASTE AND BIOMASSES." Doctoral thesis, Università degli Studi di Milano, 2019. http://hdl.handle.net/2434/694445.
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With increasing pollution and global warming of the environment, a wide spectrum of engineering technologies has emerged in food packaging to develop innovative materials with less carbon dioxide release and Green House emissions. Nowadays, an ideal food packaging must meet all the requirements of food safety and comply with environmental concerns concomitantly. One of the strategies to implement a food package that encompasses all consumer needs is to resort to eco-friendly laminates that combine several layers of materials with different functions in terms of gas/oil/water barrier and mechanical properties. The PhD research was focused on the replacement of currently used EVOH conventional gas barrier laminates with bio-based laminates containing cellulose nanocrystals (CNCs) for shelf-life extension of sensitive-oxidation foods products. Chemico-physically, cellulose is a microfibrillated structure, the most abundant biopolymer, made of millions of beta 1-4 glucose linked by glycosidic bonds; its hierarchical organization denotes from the crystalline and amorphous regions containing chains of glucose firmly hold together side-by-side by hydrogen bonds providing high tensile strength. CNCs are generally obtained by a chemical process called “top-down” either by acidic or oxidative hydrolysis of the amorphous part of cellulose. CNCs are biodegradable tiny particles whose at least one dimension is smaller than or equal to 100 nm. Actually, CNCs-coated polymers exhibit unique and extraordinary barrier properties to gases. However, since most biodegradable materials are hydrophilic by nature, CNCs tend to integrate water in wet environment which then allows the gases to pass through the coated polymers even abruptly. That phenomenon of water sensibility of CNCs was investigated in-depth during the first stage of the research and two solutions were considered plausible to alleviate that drawback, that of chemically modifying the CNCs surface for making them more hydrophobic or/and that of laminating the CNCs between two water-repellent plastic films to protect them from the humid surrounding. Standard (unmodified) and esterified (modified) CNCs were produced and characterizedto assess their functional groups, crystallinity index, apparent hydrodynamic diameter and size and hydrophilic behavior. Subsequently, plastic films were coated with standard and modified CNCs and characterized by the contact angle, Z-potential, gases permeability (Water vapor, O2, CO2). Coated-CNCs plastic films were then laminated with solvent-based polyurethanic adhesive and characterized by delamination test and gas permeability at 50% and 80% RH to evaluate the effectiveness of the lamination in the protection of CNCs coatings from the wet environment. Between 90% and 1200% improvement of gas barrier was achieved after the lamination.More importantly, the chemical modification of cellulose nanocrystals combined with the lamination resulted to be the best strategy to overcome the water sensitivity of CNCs in wet environment. Finally, a comparative food shelf-life assessment by using both synthetic (EVOH) and bio-based (CNCs) barriers laminates were successfully performed on grated cheese and ground coffee. The results obtained confirmed with certainty that CNCs implementation as a replacement of petroleum-based gas barrier is effective and that will contribute to develop more advanced and sustainable food packaging able to reduce the dependency on synthetic polymers and promoting a circular economy.
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Kochumalayil, Jose Joby. "Xyloglucan-based polymers and nanocomposites – modification, properties and barrier film applications." Doctoral thesis, KTH, Biokompositer, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-107043.
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Biopolymers from renewable resources are of interest for packaging applications as an alternative to conventional petroleum-based polymers. One of the major application areas for biopolymers is food packaging, where a candidate polymer should meet critical requirements such as mechanical and oxygen barrier performance, also in humid conditions. Starch has long been used in certain packaging applications, either in plasticized state or blended with other polymers. However, native starch has high sensitivity to water and low mechanical and barrier performance. Recently, wood-derived hemicelluloses have been extensively studied as oxygen barrier films, but suffer from low film-forming ability and mechanical performance. In the present study, xyloglucan (XG) from tamarind seed waste is explored as an alternative high-performance biopolymer in packaging applications. The obstacles of polysaccharides in terms of moisture sensitivity and processability are addressed in this thesis. In Paper I, film properties of XG were studied. XG has a cellulose backbone, but unlike cellulose, it is mostly soluble in water forming highly robust films. Moisture sorption isotherms, tensile tests and dynamic mechanical thermal analysis were performed. Enzymatic modification (partial removal of galactose in side chains of XG) was performed to study the effect of galactose on solubility and filmforming characteristics. XG films showed lower moisture sorption than starch. Stiffness and tensile strength were very high of the order of 4 GPa and 70 MPa respectively, with considerable ductility and toughness. The thermomechanical performance was very high with a softening temperature near 260 ºC. In Paper II, several plasticizers were studied in order to facilitate thermal processing of XG films: sorbitol, urea, glycerol and polyethylene oxide. Films of different compositions were prepared and studied for thermomechanical and tensile properties. Highly favorable characteristics were found with XG/sorbitol system. A large drop in glass transition temperature (Tg) of XG of the order of 100 ºC with 20 - 30 wt% sorbitol was observed with an attractive combination of increased toughness. In Paper III, XG was chemically modified and the structure-property relationship of modified XG studied. XG modification was performed using an approach involving periodate oxidation followed by reduction. The oxidation is highly regioselective, where the side chains of XG are mostly affected with the cellulose backbone well-preserved as noticed from MALDI-TOF-MS and carbohydrate analysis. Films were cast from water and characterized by dynamic mechanical thermal analysis, dynamic water vapor sorption, oxygen transmission analysis and tensile tests. Property changes were interpreted from structural changes. The regioselective modification results in new types of cellulose derivatives without the need for harmful solvents. In Paper IV, moisture durability of XG was addressed by dispersing montmorillonite (MTM) platelets in water suspension. Oriented bionanocomposite coatings with strong in-plane orientation of clay platelets were prepared. A continuous water-based processing approach was adopted in view of easy scaling up. The resulting nanocomposites were characterized by FE-SEM, TEM, and XRD. XG adsorption on MTM was measured by quartz crystal microbalance analysis. Mechanical and gas barrier properties were measured, also at high relative humidity. The reinforcement in mechanical properties and effects on barrier properties were remarkable, also in humid conditions. In Paper V, cross-linked XG/MTM composite was prepared with high clay content (ca. 45 vol%) by an industrially scalable “paper-making” method. Instead of using cross-linking molecules, cross-linking sites were created on the XG chain by selective oxidation of side chains. The in-plane orientation of MTM platelets were studied using XRD and FE-SEM. The mechanical properties and barrier performance were evaluated for the resulting 'nacre-mimetic' nanocomposites. The elastic modulus of cross-linked nanocomposites is as high as 30 GPa, one of the stiffest bionanocomposites reported.QC 20121107
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Mahajan, Kamal. "Synthesis and Characterization of New Active Barrier Polymers." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1271339021.
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Lin, Yifeng. "Improving Oxygen Barrier Property of Biaxial Oriented PET/Phosphate Glass Composite Films." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1494946200206194.
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Potts, Hayley Lynn. "Oxidation barrier and light protective packaging properties for controlling light induced oxidation in milk." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/80441.
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Fluorescent light exposure has well documented negative effects on fluid milk through oxidation reactions. A shift to light-emitting diode (LED) lights in retail dairy cases has occurred due to increased energy efficiency, but the effects of LED light on fluid milk are not known. The objective was to study the interaction of light protective additives (LPA) with a high oxygen barrier package under fluorescent and LED lighting conditions simulating a retail refrigerated dairy case. The extent of oxidation in 2% milk packaged in polyethylene terephthalate (PET) packages with different light interference properties (UV barrier, 2.1% titanium dioxide (TiO2) LPA, 4.0% TiO2 LPA, 6.6% TiO2 LPA) under light exposure up to 72h was compared to control packages (light-exposed, light-protected). Chemical measures of oxidation included dissolved oxygen content, formation of secondary lipid oxidation products, riboflavin degradation, and volatile analysis by electronic nose. Changes in dissolved oxygen content were associated closely with oxidation changes in milk over 72h. PET with 6.6% TiO2 was the most successful package, based on triangle test methodology, protecting milk sensory quality similar to light-protected milk through 8h LED light exposure. Based on a 9-point hedonic scale, (1=dislike extremely, 9=like extremely), consumers liked milk stored under LED light more (α=0.05; 6.59 ± 1.60) than milk stored under fluorescent light (5.87 ± 1.93). LED light is less detrimental to milk quality than fluorescent light and PET with high levels of TiO2 can protect milk quality for short periods of time under typical retail storage conditions.Master of Science in Life Sciences
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Rezende, Lara Barbara. "Formulation of adhesive latexes in view of enhancing barrier properties to water and oxygen." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1061.
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L'objectif de la présente thèse est d'améliorer les propriétés barrières du MetPET en conditions sévères. Plus précisément d'établir les corrélations structure-propriétés : structure du primaire d'accroche déposé en ligne sur le film PET avant métallisation et propriétés barrières et d'adhésion métal en condition sèche et humide du composite final obtenu (MetPET). L'approche choisie est la polymérisation en émulsion en régime semi-continu. Cette approche permettra d'apporter un caractère hydrophobe (phase 1-Coeur) favorisant la barrière à l'humidité et un caractère hydrophile (phase 2-Ecorce) en surface présentant des groupes fonctionnels favorables à l'adhésion métal en condition humide. De plus nous avons aussi investigué l'influences de divers additifs de formulations afin d'optimiser les propriétés du primaire d'accroche. Les latex présentant une structure de type cœur/écorce est très favorable pour la barrière à l'humidité. En effet ces latex présentent une perméabilité à l'eau sensiblement plus faible que les latex sans structure (100% composition de l'écorce). Concernant la perméabilité à l'oxygène celle-ci est principalement assurée par la couche métallique. La formulation de nos latex cœur/écorce par des agents mouillants s'est révélé indispensable pour assurer un bon étalement de nos latex sur le substrat PET. En effet nos latex issus de la synthèse ont été synthétisés avec un minimum de tensio-actif, ce qui a eu pour effet négatif d'obtenir une tension de surface trop élevée pour assurer leur mouillabilité sur le film PET. De plus cet agent mouillant a aussi montré une influence positive sur les performances d'adhésion de la couche métal sur le film PET traité avec le primaire d'accroche. La formulation de nos latex cœur/écorce par un réticulant a montré un influence positive sur les propriétés barrières aux gaz et sur les performances d'adhésion métal. Cet agent réticulant tend à favoriser la réticulation entre particule et ainsi favoriser la formation d'un film continu barrière à l'eau. De plus celui-ci apporte des fonctions de type azoté favorable aux interactions avec les atomes métallique (aluminium)The proposition of this work is to improve the barrier property of a laminate aimed to be applied in the field of packaging for foodstuffs. This laminate is constituted by a PET substrate metallized with aluminum deposited under vacuum. Given that PET is not a strongly polar polymer it is necessary to improve its adhesion to metals. This study was carried out in order to understand if there is a way to make sure that the polar groups will be bonded to the metal without being disturbed by the conditions of the environment. Our approach was the semi-batch emulsion polymerization, followed by the restructuration of the initial system (regular spherical polymeric nanoparticles) by changing its original morphology. Finally, the latexes were formulated by using variable amounts of compounds that were expected to improve the properties of the final material in terms of barrier and metallic adhesion. A part of the latexes synthesized in the scope of this work was submitted to pilot trials in an industrial line of PET extrusion. The latexes were used to coat the PET inline. The core-shell nanoparticles presented a lower permeability to water than the particles synthesized in the absence of the seed. This was related to the tortuosity promoted by the core, which increases the pathway of a diffusing molecule. The permeability to oxygen was found to be mainly related to the metallic layer. Given that the latexes were synthesized with the minimum amount of tensioactive necessary to originate stable dispersions, the wettability agent was found to be indispensable for the proper spreading of the coatings onto the PET. Furthermore, this compound played an important role on the adhesion property of the films. The cure agent, in the correct concentration, promotes the adhesion to metallic substrates. Moreover, this compound helped to prevent the interaction of the wettability agent with the water, decreasing consequently the plasticization of the structure in conditions of high humidity
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Brown, Hayley L. "The properties and performance of moisture/oxygen barrier layers deposited by remote plasma sputtering." Thesis, University of Surrey, 2015. http://epubs.surrey.ac.uk/809535/.
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The development of flexible lightweight OLED devices requires oxygen/moisture barrier layer thin films with water vapour transmission rates (WVTR) of < 10-6 g/m2/day. This thesis reports on single and multilayer architecture barrier layers (mostly based on SiO2, Al2O3 and TiO2) deposited onto glass, Si and polymeric substrates using remote plasma sputtering. The reactive sputtering depositions were performed on Plasma Quest S500 based sputter systems and the morphology, nanostructure and composition of the coatings have been examined using SEM, EDX, STEM, XPS, XRD and AFM. The WVTR has been determined using industry standard techniques (e.g. MOCON) but, for rapid screening of the deposited layers, an in-house permeation test was also developed. SEM, XRD and STEM results showed that the coatings exhibited a dense, amorphous structure with no evidence of columnar growth. However, all of the single and multilayer coatings exhibited relatively poor WVTRs of > 1 x 10-1 g/m2/day at 38 °C and 85 % RH. Further characterisation indicated that the barrier films were failing due to the presence of substrate asperities and airborne particulates. Different mechanisms were investigated in an attempt to reduce the density of film defects including incorporation of a getter layer, modification of growth kinetics, plasma treatment and polymer planarising, but none were successful in lowering the WVTR. Review of this issue indicated that the achievement of good barrier layers was likely to be problematic in commercial practice due to the cost implications of adequately reducing particulate density and the need to cover deliberately non-planar surfaces and fabricated 3D structures. Conformal coverage would therefore be required to bury surface structures and to mitigate particulate issues. Studies of the remote plasma system showed that it both inherently delivered an ionised physical vapour deposition (IPVD) process and was compatible with bias re-sputtering of substrates. Accordingly, a process using RF substrate bias to conformally coat surfaces was developed to encapsulate surface particulates and seal associated permeation paths. An order of magnitude improvement in WVTR (6.7 x 10-2 g/m2/day) was measured for initial Al2O3 coatings deposited with substrate bias. The development of substrate bias to enhance conformal coverage provides significant new commercial benefit. Furthermore, conformal coverage of 5:1 aspect ratio structures have been demonstrated by alternating the substrate bias between -222 V and -267 V, with a 50 % dwell time at each voltage. Further development and optimisation of the substrate bias technique is required to fully explore the potential for further improving barrier properties and conformal coverage of high aspect ratio and other 3D structures.
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Gällstedt, Mikael. "Films and composites based on chitosan, wheat gluten or whey proteins -Their packaging related mechanical and barrier properties." Doctoral thesis, KTH, Fibre and Polymer Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3738.
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Zhang, Yibin. "Study of Ruthenium and Ruthenium Oxide's Electrochemical Properties and Application as a Copper Diffusion Barrier." Thesis, University of North Texas, 2005. https://digital.library.unt.edu/ark:/67531/metadc4825/.
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As a very promising material of copper diffusion barrier for next generation microelectronics, Ru has already obtained a considerable attention recently. In this dissertation, we investigated ruthenium and ruthenium oxide electrochemical properties and the application as a copper diffusion barrier. Cu under potential deposition (UPD) on the RuOx formed electrochemically was first observed. Strong binding interaction, manifesting by the observed Cu UPD process, exists between Cu and Ru as well as its conductive ruthenium oxide. Since UPD can be conformally formed on the electrode surface, which enable Ru and RuOx has a potential application in the next generation anode. The [Cl-] and pH dependent experiment were conducted, both of them will affect UPD Cu on Ru oxide. We also found the Cu deposition is thermodynamically favored on RuOx formed electrochemically. We have studied the Ru thin film (5nm) as a copper diffusion barrier. It can successfully block Cu diffusion annealed at 300 oC for 10min under vacuum, and fail at 450 oC. We think the silicidation process at the interface between Ru and Si. PVD Cu/Ru/Si and ECP Cu/Ru/Si were compared each other during copper diffusion study. It was observed that ECP Cu is easy to diffuse through Ru barrier. The function of RuOx in diffusion study on Cu/Ru/Si stack was discussed. In pH 5 Cu2+ solution, Ru and Pt electrochemical behavior were investigated. A sharp difference was observed compared to low pH value. The mechanism in pH 5 Cu2+ solution was interpreted. An interesting compound (posnjakite) was obtained during the electrochemical process. An appropriate formation mechanism was proposed. Also Cu2O was formed in the process. We found oxygen reduction reaction is a key factor to cause this phenomenon.
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Kim, Junseok. "Improved Properties of Poly (Lactic Acid) with Incorporation of Carbon Hybrid Nanostructure." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/81415.
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Poly(lactic acid) is biodegradable polymer derived from renewable resources and non-toxic, which has become most interested polymer to substitute petroleum-based polymer. However, it has low glass transition temperature and poor gas barrier properties to restrict the application on hot contents packaging and long-term food packaging. The objectives of this research are: (a) to reduce coagulation of graphene oxide/single-walled carbon nanotube (GOCNT) nanocomposite in poly(lactic acid) matrix and (b) to improve mechanical strength and oxygen barrier property, which extend the application of poly(lactic acid).
Graphene oxide has been found to have relatively even dispersion in poly(lactic acid) matrix while its own coagulation has become significant draw back for properties of nanocomposite such as gas barrier, mechanical properties and thermo stability as well as crystallinity. Here, single-walled carbon nanotube was hybrid with graphene oxide to reduce irreversible coagulation by preventing van der Waals of graphene oxide. Mass ratio of graphene oxide and carbon nanotube was determined as 3:1 at presenting greatest performance of preventing coagulation. Four different weight percentage of GOCNT nanocomposite, which are 0.05, 0.2, 0.3 and 0.4 weight percent, were composited with poly(lactic acid) by solution blending method. FESEM morphology determined minor coagulation of GOCNT nanocomopsite for different weight percentage composites. Insignificant crystallinity change was observed in DSC and XRD data. At 0.4 weight percent, it prevented most of UV-B light but was least transparent. GOCNT nanocomposite weight percent was linearly related to ultimate tensile strength of nanocomposite film. The greatest ultimate tensile strength was found at 0.4 weight percent which is 175% stronger than neat poly(lactic acid) film. Oxygen barrier property was improved as GOCNT weight percent increased. 66.57% of oxygen transmission rate was reduced at 0.4 weight percent compared to neat poly(lactic acid). The enhanced oxygen barrier property was ascribed to the outstanding impermeability of hybrid structure GOCNT as well as the strong interfacial adhesion of GOCNT and poly(lactic acid) rather than change of crystallinity. Such a small amount of GOCNT nanocomposite improved mechanical strength and oxygen barrier property while there were no significant change of crystallinity and thermal behavior found.Master of Science
Book chapters on the topic "Oxygen barrier propertie"
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Cakmak, Hulya, and Ece Sogut. "Functional Biobased Composite Polymers for Food Packaging Applications." In Reactive and Functional Polymers Volume One, 95–136. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-43403-8_6.
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AbstractBiobased polymers are of great interest due to the release of tension on non-renewable petroleum-based polymers for environmental concerns. However, biobased polymers usually have poor mechanical and barrier properties when used as the main component of coatings and films, but they can be improved by adding nanoscale reinforcing agents (nanoparticles - NPs or fillers), thus forming nanocomposites. The nano-sized components have a larger surface area that favors the filler-matrix interactions and the resulting material yield. For example, natural fibers from renewable plants could be used to improve the mechanical strength of the biobased composites. In addition to the mechanical properties, the optical, thermal and barrier properties are mainly effective on the selection of type or the ratio of biobased components. Biobased nanocomposites are one of the best alternatives to conventional polymer composites due to their low density, transparency, better surface properties and biodegradability, even with low filler contents. In addition, these biomaterials are also incorporated into composite films as nano-sized bio-fillers for the reinforcement or as carriers of some bioactive compounds. Therefore, nanostructures may provide antimicrobial properties, oxygen scavenging ability, enzyme immobilization or act as a temperature or oxygen sensor. The promising result of biobased functional polymer nanocomposites is shelf life extension of foods, and continuous improvements will face the future challenges. This chapter will focus on biobased materials used in nanocomposite polymers with their functional properties for food packaging applications.
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Majeed, Khaliq, Azman Hassan, and Aznizam Abu Bakar. "Tensile, Oxygen Barrier and Biodegradation Properties of Rice Husk-Reinforced Polyethylene Blown Films." In Agricultural Biomass Based Potential Materials, 143–54. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-13847-3_7.
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Lopes, Paulo, Maria A. Silva, Alexandre Pons, Takatoshi Tominaga, Valérie Lavigne, Cédric Saucier, Philippe Darriet, Miguel Cabral, Pierre-Louis Teissedre, and Denis Dubourdieu. "Impact of the Oxygen Exposure during Bottling and Oxygen Barrier Properties of Different Closures on Wine Quality during Post-Bottling." In ACS Symposium Series, 167–87. Washington, DC: American Chemical Society, 2012. http://dx.doi.org/10.1021/bk-2012-1104.ch011.
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Di Girolamo, Giovanni. "Current Challenges and Future Perspectives in the Field of Thermal Barrier Coatings." In Production, Properties, and Applications of High Temperature Coatings, 25–59. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-4194-3.ch002.
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This chapter describes how ceramic thermal barrier coatings (TBCs) are usually applied on metal components of aircraft engines and land-based gas turbines, with the purpose to extend their lifetime as well as to increase performance and durability, by increasing the operating temperature. The TBCs have to satisfy basic requirements in terms of low thermal conductivity, high stress compliance, high sintering resistance as well as high resistance to the environmental attack promoted by oxygen, molten salts and CMAS (calcium-magnesium-alumino-silicate) deposits. This chapter is aimed at analyzing the state-of-the-art, the recent developments and the future perspectives in the field of TBCs, focusing the attention on advanced materials and new architectures as well as explaining the mechanisms affecting the failure of TBC systems.
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Shukrullah, Shazia, Muhammad Anwar, Muhammad Yasin Naz, and Inzamam Ul Haq. "Biosynthesis of Silver Nanoparticles for Study of Their Antimicrobial Effect on Plasma-Treated Textiles." In Emerging Developments and Applications of Low Temperature Plasma, 149–66. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-8398-2.ch008.
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Dielectric barrier discharges (DBD) are the configurations for the production of electrical discharges using a dielectric medium between the metallic electrodes. Plasma treatment produces negative radicals, which increase the adhesion of fabric for nanoparticles. The plasma treatment made the fabric surface rougher because of the etching effect. UV-vis spectra of the Plasmon resonance band observed at 253-400 nm. X-ray diffraction results showed that AgNPs has a cubical structure and the average crystalline size is 25 nm. SEM results determined that the morphology of the silver nanoparticles are flower shaped. The energy bandgap of AgNPs was observed at 2.59 eV. The silver nanoparticles were found to have enhanced antimicrobial properties and showed better zone of inhibition against isolated bacteria (Escherichia coli). DBD plasma treatment changed the chemical as well as physical properties of the cotton fabric. FTIR spectrum revealed that oxygen-containing groups, such as C-O, C=O, O-C-O, as well as O-C=O, increased on DBD treatment of cotton samples.
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Minamisawa, Mayumi. "Physiological Functions Mediated by Yuzu (Citrus junos) Seed-Derived Nutrients." In Citrus [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.95534.
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This section is focused on the physiological functions of yuzu (Citrus junos) to improve health. The modern lifestyle involves number of modern lifestyles involve various factors that may increase the production of active oxygen species. Nutritional supplements and medicines are commonly utilized to maintain health. Yuzu seeds contain >100-fold the limonoid content of grapefruit seeds and are rich in polyamines (PAs), including putrescine, spermidine, and spermine. Limonoid components mediate the antioxidant properties of citrus. Limonoids and PAs convey various bioactivities. PAs are closely associated with maintaining the function of the intestinal mucosal barrier, which might be involved in the metabolic processes of indigenous intestinal bacteria and in the health of the host. After ingestion, food is digested and absorbed in the intestinal tract, which is also responsible for immune responses against food antigens and intestinal bacteria. Detailed investigations of the physiological functions of extracted yuzu seed extracts may help to develop new treatment strategies against diseases associated with inflammatory responses.
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Younis, Heba, Guohua Zhao, and Hassan Abdellatif. "Pectin and Its Applicability in Food Packaging." In A Glance at Food Processing Applications. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.101614.
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Food packaging based on plastic films made from nonrenewable resources often causes environmental problems after disposal. Recently, researchers are increasingly focusing on alternative materials to reduce the use of nonbiodegradable and nonrenewable films. Generally, biomaterials are nontoxic, biocompatible, and renewable always presents reasonable film-forming ability. Thus, they are important for food safety, where undesired chemical compounds might migrate from chemicals migrate from the plastic packaging materials into foods. Pectin (PEC), as a natural carbohydrate polymer, belongs to the anionic heteropolysaccharide family and is often extracted from various residues from plant food processing, such as apple and citrus pomaces. The pectin molecules are highly branched with a backbone α-(1–4) linked D galacturonic acid. Among the naturally derived carbohydrate-based biopolymers, pectin was considered a promising substrate in fabricating edible films due to its diverse advantages, such as perfect film-forming ability, evidenced bioactivity, easy availability, and excellent quality biodegradability and biocompatibility, nontoxicity, and low cost. Pectin-based films have excellent oxygen barrier capacity and extend the shelf life for different fruits. The properties of pure pectin films can enhance through combination with other polymers or nanoparticles/fibers.
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Owusu-Akyaw Oduro, Kofi. "Edible Coating." In Postharvest Technology - Recent Advances, New Perspectives and Applications [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.101283.
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Postharvest losses are rampant due to lack of proper storage conditions and handling of the fresh food products. The perishable nature of fruits and vegetables makes their shelf life limited due to some extrinsic factors such as some environmental conditions and preservation conditions as well as some intrinsic factors such as respiration rate, ethylene production and transpiration. Among the other postharvest technologies available, edible coatings seems to be one novel method which has been verified to have a positive and safe approach to extending the shelf life of products. This type of packaging is made from various natural resources like polysaccharide, protein and lipid materials. Edible packaging materials can be divided into two main groups including edible coatings and edible films. It has so many benefits such as serving as a moisture barrier, oxygen scavenger, ethylene scavenger, antimicrobial properties among others. Different methods of application of the edible coating on the food materials include; dipping, spraying, brushing, layer by layer among others. There have been several verifications of the positive impact of edible coatings/films on pome fruits, Citrus fruits, Stone fruits, tropical and exotic fruits, berries, melon, tomatoes and others.
Conference papers on the topic "Oxygen barrier propertie"
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Li-Ao Cao and Xin-Ping Qu. "The oxygen barrier properties of CoxMoy diffusion barrier for Cu interconnect." In 2016 IEEE International Interconnect Technology Conference / Advanced Metallization Conference (IITC/AMC). IEEE, 2016. http://dx.doi.org/10.1109/iitc-amc.2016.7507719.
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Quadrini, Fabrizio, Denise Bellisario, and Loredana Santo. "Design of Nano-Filled PET Sheets With Enhanced Barrier Properties." In ASME 2018 13th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/msec2018-6413.
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Barrier properties are achieved in PET food packaging by using additives, coatings or multi-layers. An analytical model to predict the contamination during multiple recycling steps of this packaging is proposed. This model shows that lower contents of non-PET materials should be achieved to promote a valid recycling chain. A possible solution is using nano-technologies because of the very small amount of added material. Results are shown in the case of PVD coatings with aluminum target, and PET nano-composites. In both cases, less than 0.1 wt% of aluminum is able to reduce the oxygen transmission ratio of the PET packaging down to 50% of the virgin PET sheet.
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Cole, M. A., and R. Walker. "High Temperature Erosion Properties of Thermal Barrier Coatings Produced by Acetylene Sprayed High Velocity Oxygen Fuel Process." In ITSC 2000, edited by Christopher C. Berndt. ASM International, 2000. http://dx.doi.org/10.31399/asm.cp.itsc2000p1191.
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Abstract Over the past 30 years, there has been considerable interest in the development of thermally sprayed thermal barrier coatings (TBCs) for aerospace and land based turbine applications. The use of TBCs enables higher operating temperatures, resulting in significant fuel efficiency savings. This paper reports on the development of dense Yttria Stabilised Zirconia (YSZ) thermal barrier coatings produced by High Velocity Oxygen Fuel (HVOF) spraying using acetylene as the fuel gas. The use of a high temperature gas erosion rig allowed the controlled evaluation of erodent size, velocity, impact angle, and temperature on coating performance. The work also covers the optimization of process parameters, including powder morphology, stand-off distance, oxygen to fuel ratio, gas pressures, and flowrates, and their effect on coating characteristics such as deposition efficiency, microhardness, and surface roughness.
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Wilden, J., M. Wank, H. D. Steffens, and M. Brune. "New Thermal Barrier Coating System for High Temperature Applications." In ITSC 1998, edited by Christian Coddet. ASM International, 1998. http://dx.doi.org/10.31399/asm.cp.itsc1998p1669.
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Abstract YPSZ-thermal barrier coatings are widely used in industries. Nevertheies there is secure interest in TBC's for higher temperature application. Ceria or miao-alloyed ceria shows the potential to be used at higher temperatures than YPSZ. Ceria and YPSZ-Ceria-multi-layer thermal barrier coatings were produced by plasma and high velocity oxygen flame (HVOF) spraying. Bond strength and thermal shock behaviour were tested. HVOF sprayed coatings had higher content of oxygen and higher density than plasma sprayed coatings. While plasma sprayed coatings showed microcracks originating in certain phases, HVOF sprayed coatings had cracks perpendicular to the surface across the whole layer thickness. In each case the bond strength was determined by the cohesion inside the ceria coating and not by the bondage between the layers. The thermal shock resistance of each type is limited by different properties of the occuring phases caused by impurities of the used powder. However an excellent bondage between YPSZ and ceria can be achieved. Pure ceria thermal barrier coatings are not suitable due to the high diffusion of oxygen and interaction with the MCr AIY bwid coat.
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Kawakita, J., and S. Kuroda. "Restricted Oxidation of HVOF Sprayed Deposits by Composition Control of Combustion Gas." In ITSC2004, edited by Basil R. Marple and Christian Moreau. ASM International, 2004. http://dx.doi.org/10.31399/asm.cp.itsc2004p0482.
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Abstract Improved HVOF spraying with a gas shroud has been developed to fabricate environmental barrier coatings of corrosion resistant alloys such as HastelloyC. For such coatings, control of oxidation of the powder material during spraying is very important and the gas shroud has been effective to lower oxygen content to 0.19mass%. In the present study, further reduction of oxygen content to 0.063mass% was achieved by changing the composition of combustion gas by introducing nitrogen into the combustion chamber. This value is almost comparable to the oxygen content 0.042mass% of the feedstock powder but the porosity of the coating increased. Introduction of nitrogen to the combustion chamber lowered the temperature of the spray particles in flight while maintaining their high velocity. Another coating with 0.14mass% was obtained with open porosity below 0.1vol% by changing the mixing ratio of nitrogen, which exhibited improved environmental barrier property in artificial seawater.
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Fukushima, T., H. Yamada, J. Kawakita, and S. Kuroda. "Correlation of In-Flight Particle Properties and Layer Structure in HVOF Spraying." In ITSC2002, edited by C. C. Berndt and E. Lugscheider. Verlag für Schweißen und verwandte Verfahren DVS-Verlag GmbH, 2002. http://dx.doi.org/10.31399/asm.cp.itsc2002p0912.
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Abstract Previous studies have shown that gas shrouding is an effective means for controlling oxidation during HVOF spraying. In this present work, the authors attach a gas shroud to an oxyfuel torch with a longer barrel to further investigate the correlation between the state of HVOF sprayed particles and the density and oxygen content of the resulting layers. It is shown that with gas shielding, extended barrel length, and optimized spraying parameters, it is possible to accelerate powder particles to a velocity of over 750 m/sec with maintaining a high molten fraction, thereby producing very dense (zero porosity) stainless steel layers with oxygen contents less than 0.2% by weight. Paper includes a German-language abstract.
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Xiaojuan, Ji, Yu Yueguang, Zhang Deming, Li Yujie, Peng Haoran, and Hou Wei’ao. "The Effects of Impurities on The Properties of YSZ Thermal Barrier Coatings." In ITSC2018, edited by F. Azarmi, K. Balani, H. Li, T. Eden, K. Shinoda, T. Hussain, F. L. Toma, Y. C. Lau, and J. Veilleux. ASM International, 2018. http://dx.doi.org/10.31399/asm.cp.itsc2018p0553.
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Abstract Lowering the impurity content in the thermal barrier coating has the effect of improving the high temperature stability and service life. SiO2, Al2O3, TiO2 and Fe2O3 are several common low melting point oxide impurities in the YSZ (Yttria- Stabilized Zirconia) top coatings, and they all have some influence on the performance of the coatings. But there is no quantitative research on the relationship between impurity content and the properties of the coatings. In this paper, YSZ spraying materials with SiO2, Al2O3 and Fe2O3 with the content changing from less than 0.01wt% to 1wt% were designed. The bond coatings were all NiCoCrAlY and were prepared by HVOF (High-Velocity Oxygen-Fuel). The top coatings were prepared by APS (Atmospheric Plasma Spraying). The microstructure, phase structure and thermal shock resistance of the above coatings were investigated. The results showed that the increase of oxide impurity content was more prone to thermal shock failure. It shows that the oxide impurity has a significant influence on the properties of YSZ coating.
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Lee, Hyungsuk, Guangneng Zhang, and Junghyun Cho. "Protection From Oxygen and Moisture Via Thin Oxide Barrier Coating for Organic Electronics." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42509.
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Protection from oxygen and moisture is crucial for organic light emitting diodes (OLED) used in flexible display applications. The surface coating is an effective way to protect the enclosed functional materials and organic substrates in order to ensure their device functionality. Parylene films, which can be vapor deposited at room temperature, are known as a superior conformal polymeric material. In fact, a few attempts have shown that the parylene can be a good barrier coating for the OLED devices. This polymer film cannot, however, provide a long-term reliability due to nature of the polymer degradation in the presence of oxygen and moisture. In order to compensate such a drawback, we have explored the ‘biomimetic’ solution processing to deposit the oxide films on the organic substrate. Oxide films can provide a better protection and more robust surface. In this study, polyethylene terephthalate (PET) commonly used for an organic substrate, is deposited with the TiO2 films with or without the parylene underlying layer. Importantly, the oxide coating is processed at very low temperatures (< 60 °C) in aqueous solution, so the process can avoid premature failure due to high-temperature processes, and is applicable to organic structures, cheap and environment-friendly. In addition, hermeticity tests are devised to measure the moisture and oxygen permeation. Interfacial structure and mechanical properties of the resultant coatings are tested via scanning electron microscope (SEM), atomic force microscope (AFM), optical microscope (OM) and nanoindentation.
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Silva, Monica B., S. M. Guo, Nalini Uppu, Ravinder Diwan, and Patrick F. Mensah. "Thermal Property Measurements of YSZ-Al2O3 Ceramic Composites." In ASME Turbo Expo 2009: Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-59496.
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Thermal barrier coatings (TBCs) are used in gas turbine engines to achieve a higher working temperature, and thus lead to a better efficiency. Yttria-stabilized-zirconia (YSZ), a material with low thermal conductivity, is commonly used as the top coat layer to provide the thermal barrier effect. Recent studies demonstrated that YSZ-Al2O3 composite layer could reduce the oxygen diffusion through the TBC, thus YSZ-Al2O3 composite layer potentially could be used to mitigate the spalling induced failure of a TBC coating. The goal of this study is to investigate the effect of the addition of Al2O3 on the thermal properties of YSZ based TBCs. In this study, a stainless steel die was used to make disk shaped samples with 0, 1, 2, 3, 4 and 5 wt% Al2O3 /YSZ powder ratios under uniaxial pressure. A laser flash system was used to measure the thermal diffusivity for all samples and the porosity of the samples is measured using mercury porosimetry. It is found that adding Al2O3 to YSZ decreases the thermal conductivity and increases the porosity of the ceramic composites.
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Shikui, Z. "Thermal Properties of Continuously Graded Thermal Barrier Coatings Deposited by Supersonic Plasma Spray." In ITSC2005, edited by E. Lugscheider. Verlag für Schweißen und verwandte Verfahren DVS-Verlag GmbH, 2005. http://dx.doi.org/10.31399/asm.cp.itsc2005p1119.
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Abstract Continuously graded yttria stabilized ZrO2 /NiCoCrAlY coatings were prepared using a high efficiency supersonic plasma-spray system and the thermal shock properties of the coatings were studied. The specimens were so prepared that the two kinds of powders with different melting point were fed to the different regions of the plasma jet by using two powder feeders. The two powders melted perfectly at the same power, and the overheating of the powder with lower melting point was avoided. In this way, a continuously graded transition layer was obtained. The Results show that the continuous change of the coefficients of thermal expansion and thermal conductivity in the transition layer leads to a excellent thermal shock resistance of the totally 0.9mm thick TBCs. The thermal shock cycles of the specimens which underwent heating by oxygen-acetylene to 1200 C and then quenching into water reached moer than 200.The coatings’ surface was still perfect without any visible cracks. The analysis shows that the dense structure and the sufficient plastic deformation of the particles depressed the formation of TGOs, which, together with the continuously graded thermal expansion coefficient and thermal conduction coefficient, contributes to the long thermal shock resistance of the coatings. Abstract only; no full-text paper available.