Polymeric Packaging Materials Research Articles

Durability and Functionality of Conventional Polymeric Packaging Materials in Reusable Packaging Systems

Reusable packaging is increasingly recognised as a sustainable solution to address issues related to increasing packaging waste generation and harmful environmental impacts. The packaging sector consumes a significant portion of Europe’s plastic production, which is mostly single-use packaging. There is a sense of urgency to develop sustainable reusable alternatives. Unlike single-use packaging, the longevity of reusable plastic packaging is paramount, necessitating material durability and functionality. This study examines the durability of conventional polymeric packaging materials (polyethylene terephthalate (PET), polypropylene, high-density polyethylene) and investigates the effectiveness of scratch resistance additives. A specialised test set-up was created to evaluate the performance of various polymers in reusable takeaway food packaging scenarios. The research included scratch testing, wear analysis and wash cycles to assess the reuse potential of these materials. Qualitative measures were employed to compare material characteristics. Results indicated that polymer type significantly affects hardness and scratch performance, while additives had minimal impact on hardness and modulus. Although current scratch resistance additives do not effectively mitigate wear in reusable packaging in the experimental scenarios, tailored additives could present potential in increasing the durability and longevity of reusable packaging. PET demonstrated notable recovery post-washing, suggesting that washing conditions could influence material resilience. This study emphasises the need for further research to optimise scratch resistance additives and understand the impact of washing conditions on different polymers, aiming to enhance the design and longevity of reusable packaging systems.

Water vapor permeability of polymeric packaging materials for novel glass‐free photovoltaic applications

AbstractMoisture ingress in photovoltaic (PV) modules is a critical factor for performance degradation, therefore, a low water vapor transmission rate (WVTR) is highly desirable for polymers used to embed the solar cells, including backsheets, frontsheets, and encapsulants. With the advent of glass‐free modules for integration in building envelopes and vehicles, there is growing interest in polymer composite structures with embedded glass fibers to enhance rigidity. Furthermore, due to environmental concerns, there is increased interest in fluorine‐free polymers for PV applications. In this work, 21 samples with different base polymers, coatings, and/or surface treatments are investigated and their WVTRs are measured. The results show no good alternatives to existing fluoride‐based polymers/coatings for reducing WVTRs of backsheets and frontsheets among the investigated samples. In addition, glass fibers embedded within polymers to provide increased stability to backsheets or in composites for lightweight PV are shown to significantly increase WVTRs, especially, when fibers are not properly embedded, providing additional diffusion pathways for moisture ingress.

Natural Extracts and Their Applications in Polymer-Based Active Packaging: A Review.

At a time when food safety awareness is increasing, attention is paid not only to food and additives but also to packaging materials. Most current food packaging is usually made of traditional petroleum-based polymeric materials, which are not biodegradable and have adverse effects on the environment and health. In this context, the development of new non-toxic and biodegradable materials for extending the best-before date of food is receiving increasing attention. In addition, additives in packaging materials may migrate outward, resulting in contact with food. For this reason, additives are also seen as a transition from synthetic additives to natural extracts. Active extracts from animals and plants having good antioxidant and antibacterial properties are also beneficial for human health. It is indisputable that active extracts are ideal substitutes for synthetic additives. Polymer packaging materials combined with active extracts not only maintain their original mechanical and optical properties and thermal stability but also endow polymers with new functions to extend the shelf life of food. This review paper provides an overview of this promising natural extract-containing polymer-based active packaging, with a focus on plant essential oils (containing phenolics, monoterpenes, terpene alcohols, terpene ketones, and aldehydes), pigments (procyanidins), vitamins (vitamin B), and peptides (nisin). In particular, this paper covers the research progress of such active extracts, in single or compound forms, combined with diverse polymers (mostly biopolymers) for food packaging applications with particular focus on the antioxidant and antibacterial properties of packaging materials.

Recycling waste polymer packaging materials as effective active carbon porous materials for uranium removal from commercial phosphoric acid

Abstract Plastic packaging waste is considered a serious threat to the environment due to its non-biodegradable nature. Transforming plastic waste into active carbons using pyrolysis methods could be a valuable option to solve the challenge of plastic waste. Synthesized active carbon was differentiated using zeta potential, particle size, SEM, BET, and DSC. This study also investigates the use of obtained active carbons for U(VI) removal from commercial phosphoric acid. The kinetics of adsorption were found to follow the pseudo-second-order model and intra-particle diffusion as one of the controlling mechanisms. Langmuir, and Freundlich, isotherms were employed to explore the equilibrium data. Furthermore, thermodynamic investigations revealed that uranium uptake is an endothermic, feasible, and spontaneous process. The present study concludes that plastic waste-based activated carbon could be employed as a low-cost alternative to commercial activated carbon for uranium removal from phosphoric acid and the production of green fertilizers.

Life cycle assessment of a marine biorefinery producing protein, bioactives and polymeric packaging material

Abstract Purpose Algal research has been dominated by the use of marine biomass (mainly microalgae) as feedstock in the production of second-generation biofuels, albeit with limited economic success. A promising alternative strategy is the valorisation of seaweed (macroalgae), with the cascaded extraction of its high-value components, as well as lower-value components further downstream, under the ‘biorefinery concept’. The goal of this study was to assess the environmental performance of one such marine biorefinery situated in the UK. Methods Attributional life cycle assessment (LCA) was conducted on a hypothetical marine biorefinery coproducing fucoidan, laminarin, protein and alginate/cellulose packaging material (target product), from cultivated Saccharina latissima. The functional unit was the production of 1 kg of packaging material. A total of 6 scenarios were modelled, varying in coproduct management methodology (system expansion, mass allocation or economic allocation) and applied energy mix (standard or green energy). Sensitivity analysis was also conducted, evaluating the systems response to changes in allocation methodology; product market value; biomass composition and transport mode and distance. LCA calculations were performed using OpenLCA (version 1.10.3) software, with background processes modelled using the imported Ecoinvent 3.6 database. Environmental impacts were quantified under ReCiPe methodology at the midpoint level, from the ‘Heirarchist’ (H) perspective. Results and discussion The overall global warming impacts ranged from 1.2 to 4.52 kg CO2 eq/kg biopolymer, with the application of economic allocation; 3.58 to 7.06 kg CO2eq/kg with mass allocation and 14.19 to 41.52 kg CO2eq/kg with system expansion — the lower limit representing the instance where green electricity is used and the upper where standard electricity is employed. While implementing the green energy mix resulted in a 67% reduction in global warming impacts, it also incurred a 2–9 fold increase in overall impacts in the categories of terrestrial acidification, human non-carcinogenic toxicity, land-use and terrestrial ecotoxicity. Economic allocation resulted in burden shifting most favourable to the packaging material pathway. Conclusions This study demonstrates that the road to environmental optimisation in marine biorefineries is fraught with trade-offs. From the perspective of LCA — and by extension, the eco-design process that LCA is used to inform — when evaluating such product systems, it serves to strike a balance between performance across a broad spectrum of environmental impact categories, along with having consideration for the nature of energy systems incorporated and LCA methodological elements. Graphical Abstract

Применение полимерных упаковочных материалов для хранения растительных объектов в модифицированной газовой среде

В настоящей статье рассмотрены вопросы хранения фруктов, овощей и грибов в условиях модифицированной газовой среды с применением гибких полимерных упаковочных материалов с различными барьерными свойствами. Модифицированная газовая среда внутри упаковки может быть создана двумя способами: активным (наполнение газовой смесью заданного состава) и пассивным (формирование газового состава только вследствие дыхания). Пониженное содержание кислорода способствует снижению интенсивности дыхания и, следовательно, замедлению биохимических процессов, связанных с дозреванием и старением растительных объектов. При этом замедляются расходование углеводов и потеря влаги, что способствует сохранению тургора растительной ткани и, следовательно, приемлемых органолептических характеристик в течение более длительного времени. При пониженном содержании кислорода также замедляется окисление полифенольных веществ, что способствует сохранению окраски фруктов, овощей и грибов. В то же время газопроницаемость упаковочного материала должна быть подобрана таким образом, чтобы не допустить снижения содержания кислорода ниже критического уровня, при котором создаются анаэробные условия. Газопроницаемость полимерных пленок зависит от структуры макромолекул и характера межмолекулярного взаимодействия. Гибкость макромолекул и ослабление межмолекулярного взаимодействия способствуют росту газопроницаемости, а увеличение числа межмолекулярных связей (сшивка полимера) – ее уменьшению. Также важным условием сохранения растительных объектов в свежем виде является поддержание оптимального уровня влажности внутри упаковки. Однако при этом следует избегать конденсации водяного пара, так как наличие капельной влаги создает условия для прорастания спор плесневых грибов. Для этой цели обычно используют пленки с перфорацией, что обеспечивает отведение избыточной влаги. This article discusses the storage of fruits, vegetables and mushrooms in a modified atmosphere using flexible polymer packaging materials with different barrier properties. A modified gaseous environment inside the package can be created in two ways: active (filling with a gas mixture of a given composition) and passive (formation of a gas composition only due to breathing). A reduced oxygen content contributes to a decrease in the intensity of respiration and, consequently, to a slowdown in the biochemical processes associated with the ripening and aging of plant objects. At the same time, the consumption of carbohydrates and the loss of moisture slow down, which contributes to the preservation of plant tissue turgor and, consequently, acceptable organoleptic characteristics for a longer time. With a reduced oxygen content, the oxidation of polyphenolic substances also slows down, which contributes to the preservation of the color of fruits, vegetables and mushrooms. At the same time, the gas permeability of the packaging material must be chosen in such a way as to prevent the oxygen content from falling below the critical level at which anaerobic conditions are created. The gas permeability of polymer films depends on the structure of macromolecules and the nature of intermolecular interactions. The flexibility of macromolecules and the weakening of intermolecular interaction contribute to an increase in gas permeability, and an increase in the number of intermolecular bonds (polymer crosslinking) – to its decrease. Also, an important condition for keeping plant objects fresh is maintaining an optimal level of humidity inside the package. However, water vapor condensation should be avoided, as the presence of drip moisture creates conditions for the germination of mold spores. For this purpose, perforated films are usually used, which ensures the removal of excess moisture.

Corn starch nanocomposite films reinforced with nanocellulose

Abstract The need for flexible food packaging has increased substantially in recent years around the world due to the unprecedented growth in food consumption. Due to low cost and ease of processing, petroleum-based synthetic polymer packaging materials are being predominantly used for food packaging these days. To avoid contributing to environmental problems caused by ecological risks, consumers have been searching for alternatives to plastic food packaging due to the fact that plastics cannot be recycled and are not biodegradable. Therefore, bioplastics made from corn starch, which are biodegradable, can be one solution to these issues. The starch’s amylopectin and amylase composition has a significant impact on the polysaccharide’s characteristics. Corn starch (CS) is utilized as a food source for humans and other animals, but it also has many other applications in industry. Corn starch, on the other hand, has a few issues that need to be addressed through some modifications. Although starch-based packaging is expensive, they create less waste overall, which helps in the reduction amount of plastic pollution. A variety of natural and synthetic polymers – including polysaccharide-based materials like Kappaphycus alvarezii seaweed, collagen, alginate, chitosan, zein, cellulose, gelatin, various amino acids and polymeric materials like acrylic acid, polybutylene (PB), polyacrylic acid, polyethylene (PE), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), and polycaprolactone (PCL) – are used as starch modifiers to produce polymers with a starch base that are completely biodegradable. These biopolymers have the potential to replacing petroleum-based polymers in a variety of commercial and industrial settings. Besides, corn starch nanocomposite films reinforced with nanocellulose have been investigated as a potential eco-friendly packaging material. Consequently, the effects of nanocellulose content on the mechanical, thermal, and barrier properties of corn starch-based films will be discussed in this work.

Comprehensive Assessment Of The Quality Of Canned Meat In Combined Packaging Materials

The article presents a comparative assessment of the quality and safety of canned meat from different manufacturers in modern types of combined and polymer packaging materials. Canned meat in lamister jars (6 samples), in retort bags (4 samples), in polypropylene cans (2 samples) were taken into the study. The results showed that all the samples studied, with the exception of two, met the requirements of regulatory documents. To compare the quality of the tested canned food samples, the qualimetry method was used. With the help of a qualimetric model, a rating of the quality of canned food from different manufacturers was compiled, taking into account organoleptic, physical-chemical indicators, storage capacity and nutritional value.

Preserving Ready-to-Eat Meals Using Microwave Technologies for Future Space Programs

The crewed suborbital and space flights launched by private companies over the past three years have rejuvenated public interest in space travel, including space tourism. Ready-to-eat meals (MREs) are the main source of nutrients and energy for space travelers. It is critical that those meals are free of bacterial and viral pathogens and have adequate shelf life. The participation of private companies in space programs will create new opportunities and demand for high-quality and microbiologically safe MREs for future space travels. In this article, we provide a brief review of nutrition and energy requirements for human activities in space. We discuss the general thermal processing requirements for control of bacterial and viral pathogens in MREs and introduce advanced thermal preservation technologies based on microwaves for production of MREs with different shelf-lives under various storage conditions. We also present the latest advancements in the development of polymer packaging materials for quality preservation of thermally stabilized MREs over extended storage. Finally, we recommend future research on issues related to the sensory quality of specially formulated MREs, microbial safety of dried foods that complement high moisture MREs, and food package waste management in future space missions.

Application of inverse problems in diffusivity coefficient estimation of polymeric packaging materials and food shelf-life determination

An effective analysis method with multiple accelerant factors is needed for rapid shelf-life determination for foods. This study aimed to investigate the effect of environmental oxygen pressure on oxygen diffusivity in polyethylene terephthalate (PET), high-density polyethylene (HDPE) and polypropylene (PP) bottles. The bottles were placed in custom-made high-pressure (10–30 psig) chambers with a 100% oxygen environment after filled with water and flushed with nitrogen to reduce the internal oxygen level below 2%. Bottles were subjected to three pressure levels and the accumulation of headspace and dissolved oxygen was used to estimate the diffusivity with the inverse problems approach. Modelling of diffusion was performed by numerically solving Fick’s law and the sequential estimation of the diffusion coefficient was performed based on the Gauss minimization method. The oxygen diffusion coefficient of PET, HDPE and PP was in the range of 0.78−1.16x10−13 m2s−1, 0.14−0.46x10−13 m2s−1 and 0.59−14.09x10−16 m2s−1, respectively. The application of oxygen pressure significantly increased the rate of oxygen transfer for all packaging materials compared to the control samples at ambient pressure. The application of inverse problems enabled the determination of the diffusion coefficient of oxygen with minimal errors and small confidence intervals. The use of elevated pressure and temperature as accelerants has potential application in rapid shelf-life determination of foods.

Improvement of polyvinyl alcohol/casein blend film properties by adding cellulose nanocrystals

AbstractThis study aims to prepare and examine the properties of poly(vinyl alcohol)/casein (PVA/CAS) based films reinforced with cellulose nanocrystals (NC), which can be presented as an alternative to petroleum‐based polymer packaging materials. PVA/CAS and 0.5–1–3–5 wt% NC containing PVA/CAS biocomposite films were prepared by solution casting method. Afterward, the 1NC film, which exhibited the best mechanical properties, was crosslinked with various amounts of glyoxal. Structural, morphological (polarized optical microscope), mechanical (tensile), thermal (differential scanning calorimetry, thermogravimetric analysis), contact angle, and water vapor transmission rate (WVTR) properties of the samples were investigated. The 1NC film exhibited the highest tensile strength (TS) and elongation values in PVA/CAS/NC films, and its mechanical properties decreased due to agglomeration with increasing NC amount. As expected, crosslinking improved the TS. The thermal stability of the PVA/CAS film was generally improved with the addition of NC and crosslinking. The high WVTR value of the PVA/CAS film decreased with the addition of NC and the 1NC film presented the lowest value. Thanks to the complex structure formed as a result of crosslinking and the reduced free volume, the WVTR of the 1NC film has reduced. The results showed that PVA/CAS‐based films with good mechanical properties and water vapor barrier are promising as packaging materials.

A green/sustainable organocatalytic pathway for the preparation of esterified supercriticalCO2‐dried potato starch products

AbstractProduction of renewable and modified starch‐based products was achieved using a sustainable catalyst and an environmentally friendly drying process via supercritical CO2. Potato starch was modified via a sustainable and green esterification process with acetic anhydride reagent implementing a novel organocatalytic pathway at different periods of time (0.5, 3 and 7 h) by applying an esterification reaction at 120°C targeting intermediate degrees of substitution (i.e., 0.2 < DS <1.5) finding potential applications as polymer packaging materials. The final modified samples were divided into two fractions, where the first fraction was dried under vacuum at 80° C for 24 h and the second fraction was dried under supercritical CO2at 40° C and 100 bars for 2 h. The final products were analyzed using an array of characterization techniques such as Fourier transform infrared (FTIR), Proton nuclear magnetic resonance (1H‐NMR), scanning electron microscopy (SEM), X‐ray diffraction (XRD), N2physisorption, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Karl Fischer. The chemical structure of both fractions was similar as confirmed by the different characterization techniques. Drying under supercritical CO2preserved some pores in the modified starch materials as opposed to thermal oven drying, as was confirmed by N2physisorption measurements. The degree of substitution (DS) was determined using three different techniques; titration, high performance liquid chromatography (HPLC) and solution state proton nuclear magnetic resonance (1H NMR) spectroscopy and the values were greater than 0.2 and less than 1.5 indicating intermediate degrees of substitution.

Properties enhancement of packaging materials based on gelatin

AbstractThe main disadvantages of plastic materials are that they do not readily break down in the environment and cause harmful effects. For a specific use, biodegradable and/or edible films have been produced to totally replace some typical polymeric packaging materials. Protein and polysaccharides biopolymers have film‐forming properties that are useful for food packaging. Gelatin is an example of a protein that has the ability to form a film, has strong functional qualities, and can be used as an exterior barrier to prevent drying. Gelatin has adverse effects on food packaging application, especially mechanical properties and water vapor permeability. The effect of the incorporation of plasticizers in gelatin films is reviewed and presented. The plasticizer can improve the extensibility, dispensability, flexibility, elasticity, and rigidity of biopolymers and biopolymers composites. The plasticizers reviewed are glycerol, sorbitol, lignin, root essential oils, bergamot oil, lemongrass oil, sucrose, oleic acid, malic acid, and citric acid, and others. These plasticizers have strengthened the film structure by continuity of polymer matrix where the gelatin films become more stretchable and also flexible. This study also discussed the effect of plasticizers on other properties of gelatin film such as water vapor permeability (WVP), thermal properties, water‐solubility, moisture content, oxygen permeability, light transmission, and transparency.

Pre-Ball-Milled Boron Nitride for the Preparation of Boron Nitride/Polyetherimide Nanocomposite Film with Enhanced Breakdown Strength and Mechanical Properties for Thermal Management.

Modern electronics not only require the thermal management ability of polymer packaging materials but also need anti-voltage and mechanical properties. Boron nitride nanosheets (BNNS), an ideal thermally conductive and high withstand voltage (800 kV/mm) filler, can meet application needs, but the complex and low-yield process limits their large-scale fabrication. Herein, in this work, we prepare sucrose-assisted ball-milled BN(SABM-BN)/polyetherimide (PEI) composite films by a casting-hot pressing method. SABM-BN, as a pre-ball-milled filler, contains BNNS and BN thick sheets. We mainly investigated the thermal conductivity (TC), breakdown strength, and mechanical properties of composites. After pre-ball milling, the in-plane TC of the composite film is reduced. It decreases from 2.69 to 2.31 W/mK for BN/PEI composite film at 30 wt% content; however, the through-plane TC of composites is improved, and the breakdown strength and tensile strength of the composite film reach the maximum of 54.6 kV/mm and 102.7 MPa at 5 wt% content, respectively. Moreover, the composite film is used as a flexible circuit substrate, and the working surface temperature is 20 ℃, which is lower than that of pure PEI film. This study provides an effective strategy for polymer composites for electronic packaging.

Use of automatic tensile testing machines for assessing the strength properties of packaging materials for baked confectionery products

The authors conducted this study to assess the influence of the strength properties of packaging materials for baked confectionery products on the tensile strength, fracture strength, and elongation level. The purpose of this study was to evaluate the mechanical properties (impact strength, fracture strength, and distance to fracture). The paper presents a brief overview of modern methods of functional and operational properties control for polymer packaging materials used for food products and describes their features. The objects of the study were samples of packaging for gingerbread purchased from trade organizations. It has been shown that quality control of polymer packaging materials for food is key in determining the possibility of their intended use. The test results allow evaluating the possibilities and limitations, optimizing the technological process, and obtaining high-quality packaging. In conclusion, the authors give recommendations to gingerbread manufacturers to increase the competitiveness of the product and meet consumer demand.

Utilization of polymer packaging materials as a basis of environmental safety: biodegradable and edible materials

The introduction presents an analysis of waste disposal methods used in different countries, which indicates certain difficulties in the disposal of polymer waste due to their greatest environmental danger, since synthetic polymers decompose for a long time in natural conditions. Today, high requirements for environmental protection dictate the emergence of new types of processing of polymer waste through their self-destruction. An actual direction in the packaging industry is the production of environmentally friendly self-destructible packaging: biodegradable and edible. The basis for the production of such packages is raw materials of animal and vegetable origin. The purpose of the work is to substantiate the advantages of self-destructible packaging as an environmentally friendly material that does not harm the environment. The main part of the article provides information about the advantages of biodegradable and edible packaging materials. The advantage of biodegradable packaging is its ability to degrade into natural components that do not require separate collection, sorting, recycling or other disposal solutions. The disposal costs of such packaging are minimal, since the waste is decomposed under the influence of natural factors: water, various types of radiation or microorganisms. Edible packaging is the only type of biodegradable plastic packaging that does not require individual collection and special disposal conditions. Such packages have a high sorption capacity, which allows them to have a positive physiological effect on the human body, enriching food with minerals, vitamins, complexes of microelements, bioflavonoids, regulating the taste and aroma properties of the packaged food product and simplifying the nutrition process. In the conclusion, it is noted that the solution to the problems of recycling packaging materials indicates a global trend in the field of creating self-destructible materials – biodegradable and edible, the prospects of which are aimed at preserving the environment.

Bio-based materials for barrier coatings on paper packaging.

Research into alternative packaging materials is becoming more and more popular as a result of growing eco-friendly concerns regarding the usage of some petroleum-based polymeric packaging materials and coatings, as well as growing buyer demands for products with nutritious quality and extended shelf lives. Barrier coatings made of naturally renewable biopolymers can be applied to paper packing materials. These biopolymer coatings have the potential to replace the current synthetic paper and paperboard coatings, are strong oxygen and oil barriers, and may prevent the unintended moisture transfer in food goods. An appealing method of controlling the growth and spread of microorganisms in food packaging is the integration of antimicrobial compounds into coatings to create active/functional paper-based packaging materials. Here, in this review of the oxygen/moisture barrier, mechanical, and other characteristics of paper coated with bio-based materials. Examples are used to discuss the current and future uses of bio-based material coatings on paper packaging materials to improve barrier performance.

Food Packaging Materials with Special Reference to Biopolymers-Properties and Applications

Food is an important material for survival. The increasing world population, urbanization, and globalization are responsible for more food. This has increased challenges in food storage and safety. Therefore, it is necessary to preserve food by suitable packaging materials. The packaging materials are useful for giving longer life to the food and improving quality during transportation, storage and distribution. Innovations and developments in food packaging, have become very important in the food industry. Variety of packaging materials such as plastics, paper, metal, and glass are used in food packaging. Most widely used packaging materials are non-biodegradable plastics but these are harmful to environment and human health. Therefore, the food industry is in search of environment friendly replacement of non-biodegradable plastics by biodegradable plastics. However, no systematic literature is available on the subject, so there is a need to summarise the available information in a systematic way. Polymer packaging materials with special reference to biodegradable plastics have been discussed in detail. Different type of biodegradable plastics with their functionality and applications in food packaging have been summarised. Literature available has shown that biodegradable plastics are much better for food packaging as compared to other packaging materials. Increasing fundamental research in the use of biodegradable polymers in food packaging and effort to protect the environment, requires deep understanding and there are lot of challenges for commercialization, which are to be tackled. All these aspects have been discussed in this review article.

Elucidating the large variation in ion diffusivity of microelectronic packaging materials

The risk of corrosion poses a challenge to meet the stringent reliability requirements of microelectronic devices that are used in harsh environments. Microelectronic devices are often encapsulated in polymer packaging materials, which protect them from corrosion. These polymers are, however, not completely hermetic and thus allow small amounts of ions and moisture to reach the device, which might cause corrosion of the microelectronic circuitry. To improve and predict the reliability of the device, it is important to quantify the ion diffusivity in these materials. Previously reported values for the ion diffusivity vary by multiple orders of magnitude for a single class of material. Here, we investigate the causes for this discrepancy using three experimental methods: (i) saltwater immersion, (ii) diffusion cell measurements, and (iii) transient electric current measurements. Several materials, such as silicone, epoxy, and polyamide, were tested to cover the broad spectrum of polymers used by the microelectronics industry. We found that the discrepancies are likely due to the strong dependence of the ion diffusivity on both the moisture content within the polymers, as well as on the salt concentration and pH of the solutes. Furthermore, we found that the very low ion diffusivity causes long measuring times, and thus a large risk for errors from contamination, leakage, or minor defects in the samples.

Oxygen Scavenging Hybrid Nanostructure: Localization of Different Iron Nanoparticles on Montmorillonite Clays Host.

According to the great potential of zero-valent iron nanoparticle applications in the environmental, medical, chemical, packaging and many other industries, there is still a need to tailor their production methods. This study reports the production of a hybrid nanostructure based on iron nanoparticles (INPs) produced in/on montmorillonite (MMT) nanoclays as an oxygen scavenger and barrier additive in polymeric packaging materials of oxygen-sensitive products. INPs and MMT were demonstrated to have effective mutual interactions in which the MMT host played a chemophysical trapping role for iron particles, causing smaller particles around 10 nm with 6.2 g/m2 higher specific surface area by limiting particle growth and agglomeration. In return, the embedding of primary iron cations in/on clays and growth of these particles during the reduction reaction pushed the clay layers out and helped further clay intercalation–exfoliation. Effective study of solvent and primary cation (Fe2+/Fe3+) types showed different preferences in interacting with natural and alkylammonium-modified MMT, resulting in the different site selection. Fe2+ cations preferred to migrate to the interlayer space, whereas Fe3+ cations tended to bond to the clay surface. The obtained results in this study suggest tailoring the ultimate oxygen scavenging capacity, shelf life, and migration properties of a hybrid nanoparticle according to the application requirements.