Search

It is a formidable challenge in thermoplastic/lignin composites to simultaneously boost tensile strength and elongation performance due to the rigidity of lignin. To address this issue, sodium-alginate-doped lignin nanoparticles (SLNPs) were prepared by combining solvent exchange and a coprecipitation method and used as an eco-friendly filler for poly(butylene adipate-co-terephthalate) (PBAT). The results indicated that the 1% polyanionic sodium alginate solution contributed to the formation of SLNP in lignin/THF solution. SLNP with a mean hydrodynamic diameter of ~500 nm and a Zeta potential value of −19.2 mV was obtained, indicating more hydrophobic lignin nanoparticles and a smaller number of agglomerates in SLNP suspension. Only 0.5 wt% SLNP addition improved the yield strength, tensile strength, and elongation at break by 32.4%, 31.8%, and 35.1% of the PBAT/SLNP composite films, respectively. The reinforcing effect resulted from the rigid aromatic structure of SLNP, whereas the enhanced elongation was attributed to the nanostructural feature of SLNP, which may promote boundary cracking. Additionally, the PBAT/SLNP composite films displayed excellent ultraviolet (UV) resistance with a UV shielding percentage near 100% for UVB and more than 75% for UVA, respectively. The addition of SLNP hindered water vapor, enhancing the moisture barrier properties. Overall, this study provides an effective strategy to eliminate the decrement in elongation performance for PBAT/lignin composites and suggest they are good candidates to be extensively utilized. [ABSTRACT FROM AUTHOR]

BACKGROUND: Encapsulation is commonly used to protect probiotics against harsh stresses. Thus, the fabrication of microcapsules with special structure is critical. In this work, microcapsules with the structure of S/O/W (solid-in-oil-in-water) emulsion were prepared for probiotics, with butterfat containing probiotics as the inner core and with whey protein isolate fibrils (WPIF) and antioxidants (epigallocatechin gallate, EGCG; glutathione, GSH) as the outer shell. RESULTS: Based on the high viscosity and good emulsifying ability of WPIF, dry well-dispersed microcapsules were successfully prepared via the stabilization of the butterfat emulsion during freeze-drying with 30-50 g L-1 WPIF. WPIF, WPIF + EGCG, and WPIF + GSH microcapsules with 50 g L-1 WPIF protected probiotics very well against different stresses and exhibited similar inactivation results, indicating that EGCG and GSH exerted neither harm or protection on probiotics. This significantly reduced the harmful effects of antioxidants on probiotics. Almost all the probiotics survived after pasteurization, which was critical for the use of probiotics in other foods. The inactivation values of probiotics in microcapsules were around 1 log in simulated gastric juice (SGJ), about 0.5 log in simulated intestinal juice (SIJ), and around 1 log after 40 days of ambient storage. CONCLUSION: Dry S/O/W microcapsule, with butterfat containing probiotics as the inner core and WPIF as the outer shell, significantly increased the resistance of probiotics to harsh environments. This work proposed a preparation method of dry S/O/W microcapsule with core/shell structure, which could be used in the encapsulation of probiotics and other bioactive ingredients. [ABSTRACT FROM AUTHOR]

In this study, two multi-layer fabric systems intended for firefighters have been tested in order to determine the basic parameters of thermal comfort. The thermal comfort is evaluated effectively by measuring the thermal properties of clothing on the sweating-guarded hotplate (skin model). The first assembly is composed of an external layer, a middle layer (thermal insulation), and an inner layer [moisture barrier - hydrophilic polyurethane (PU) membrane coated on knitted fabric]. The second one contains an external layer, a middle layer (thermal insulation), and an inner layer (liner). Both assemblies contain the same external layer and middle layer. These layers are tested as monolayers and in multi-layer clothing systems. The influence of the membrane on the thermal and water-vapour resistance of the multi-layer fabric system has been studied. When the combinations of different materials are used for a multi-layer fabric system, the thermal comfort is dependent not only on the properties of each monolayer but also on the manner in which they act together. The results show that the monolayer acting as a moisture barrier has a considerable influence on the overall watervapour transport abilities. The position of the moisture barrier in the assembly is also important in the overall value of watervapour resistance of the multi-layer system. [ABSTRACT FROM AUTHOR]

It is a formidable challenge in thermoplastic/lignin composites to simultaneously boost tensile strength and elongation performance due to the rigidity of lignin. To address this issue, sodium-alginate-doped lignin nanoparticles (SLNPs) were prepared by combining solvent exchange and a coprecipitation method and used as an eco-friendly filler for poly(butylene adipate-co-terephthalate) (PBAT). The results indicated that the 1% polyanionic sodium alginate solution contributed to the formation of SLNP in lignin/THF solution. SLNP with a mean hydrodynamic diameter of ~500 nm and a Zeta potential value of −19.2 mV was obtained, indicating more hydrophobic lignin nanoparticles and a smaller number of agglomerates in SLNP suspension. Only 0.5 wt% SLNP addition improved the yield strength, tensile strength, and elongation at break by 32.4%, 31.8%, and 35.1% of the PBAT/SLNP composite films, respectively. The reinforcing effect resulted from the rigid aromatic structure of SLNP, whereas the enhanced elongation was attributed to the nanostructural feature of SLNP, which may promote boundary cracking. Additionally, the PBAT/SLNP composite films displayed excellent ultraviolet (UV) resistance with a UV shielding percentage near 100% for UVB and more than 75% for UVA, respectively. The addition of SLNP hindered water vapor, enhancing the moisture barrier properties. Overall, this study provides an effective strategy to eliminate the decrement in elongation performance for PBAT/lignin composites and suggest they are good candidates to be extensively utilized.

The rate of plastic deterioration is currently significantly outpacing the rate at which plastic waste is being produced, leading to a biome-wide imbalance. Biopolymers derived from sustainable raw materials are widely explored as potential alternative packaging materials to increase the shelf-life of fresh produce and processed food. The present work aims to develop polysaccharide-based composite films. Sodium alginate- and castor oil-blended pectin films were developed as per the 23 (two-level three-factor) factorial design of experiments. Sodium alginate was used as a stabilizer and film-forming agent to enhance the mechanical properties of the films. Castor oil was used as an additive to improve the moisture barrier and antimicrobial properties. D-sorbitol was used as a plasticizer to improve the flexibility of the films. The amounts of sodium alginate (25% and 50% w/w), castor oil (10% and 15% w/w), and D-sorbitol (15% and 30% w/w), with respect to pectin, and the sonication time were chosen as the four factors. Based on our prior optimization studies, all other process variables, such as pH (<4), drying temperature (60 °C), and humidity (40%), were maintained constant. The moisture barrier, mechanical, surface hydrophobicity, morphological, thermal stability properties, and biodegradability characteristics of each film were studied. All films were thin (~0.110 ± 0.004 mm) and transparent (ΔΕ = 3 to 11). The moisture barrier properties improved three-fold compared to pure pectin films. The elongation at break increased at least three times. The films were thermally stable at 400 °C. The melting point of the films increased to 150 °C, compared to 95 °C of the pure pectin film. [ABSTRACT FROM AUTHOR]

We describe here the fabrication, characterization, and properties of tough bioplastics made of a babassu oil-based acrylic polymer (PBBM), hemicellulose xylan grafted with PBBM chains, and carnauba wax (CW). The plastic was primarily designed to obtain bioderived materials that can replace low-density polyethylene (LDPE) in certain food packaging applications. To obtain plastic, the radical polymerization of an original babassu oil-based acrylic monomer (BBM) in the presence of xylan macromolecules modified with maleic anhydride (X-MA) was conducted. The polymerization resulted in a material (PBBM-X) mostly consisting of highly branched PBBM/X-MA macromolecules. PBBM-X has a glass transition of 42 °C, a storage modulus of 130 MPa (at 25 °C, RT), and a Young's modulus of 30 MPa at RT. To increase the moduli, we blended PBBM-X with carnauba wax, a natural material with a high modulus and a melting temperature of ~80 °C. It was found that PBBM-X is compatible with the wax, as evidenced by the alternation of the material's thermal transitions and the co-crystallization of BBM side alkyl fragments with CW. As a result, the PBBM-X/CW blend containing 40% of the wax had a storage modulus of 475 MPa (RT) and a Young's modulus of 248 MPa (RT), which is close to that of LDPE. As polyethylene, the PBBM-X and PBBM-X/CW bioplastics have the typical stress-strain behavior demonstrated by ductile (tough) plastics. However, the bioplastic's yield strength and elongation-at-yield are considerably lower than those of LDPE. We evaluated the moisture barrier properties of the PBBM-X/(40%)CW material and found that the bioplastic's water vapor permeability (WVP) is quite close to that of LDPE. Our bioderived material demonstrates a WVP that is comparable to polyethylene terephthalate and lower than the WVP of nylon and polystyrene. Taking into account the obtained results, the fabricated materials can be considered as polyethylene alternatives to provide sustainability in plastics production in the packaging areas where LDPE currently dominates. [ABSTRACT FROM AUTHOR]

Photonic films based on cellulose nanocrystals (CNCs) are sustainable candidates for sensors, structurally colored radiative cooling, and iridescent coatings. Such CNC‐based films possess a helicoidal nanoarchitecture, which gives selective reflection with the polarization of the incident light. However, due to the hygroscopic nature of CNCs, the structural colored material changes and may be irreversibly damaged at high relative humidity. Thus, moisture protection is essential in such settings. In this work, hygroscopic CNC‐based films are protected with a bioinspired synthetic plant cuticle; a strategy already adopted by real plants. The protective cuticle layers altered the reflected colors to some extent, but more importantly, they significantly reduced the water vapor permeance by more than two orders of magnitude, from 2.1 × 107 (pristine CNC/GLU film) to 12.3 × 104 g µm m−2 day−1 atm−1 (protected CNC/GLU film). This expands significantly the time window of operation for CNC/GLU films at high relative humidity. [ABSTRACT FROM AUTHOR]

Edible films and coatings developed through biopolymers have good tensile strength and gaseous barriers but lack moisture barrier properties. To improve the moisture barrier properties of sodium alginate and whey protein-based films, carnauba wax at different concentrations (0.5, 1.0, and 1.5%) was incorporated. Results showed significant variations as the concentration of the carnauba wax increased. The addition of wax at a higher concentration (1.5%) significantly improved the moisture barrier properties (3.12 ± 0.31 g.mm/kPa.h.m2). However, tensile strength reduced (3.92 ± 0.04 to 3.34 ± 0.04 MPa) with the increase in wax concentration. The incorporation of lipid constituents in the emulsion-based films also affects the physicochemical properties including thickness, droplet size, transparency, and microstructure of the films as well. At lower concentrations (0.5%) films showed uniform microstructure and better transparency (81.82 ± 1.63%) but lack in moisture barrier properties. Emulsified edible films with improved moisture barrier and tensile properties are preferable in the food packaging industry. Emulsion-based films and coatings have potential applications in foods, especially in fresh and processed foods, dairy, bakery products, meat, and sausages. [ABSTRACT FROM AUTHOR]

Abstract Photonic films based on cellulose nanocrystals (CNCs) are sustainable candidates for sensors, structurally colored radiative cooling, and iridescent coatings. Such CNC‐based films possess a helicoidal nanoarchitecture, which gives selective reflection with the polarization of the incident light. However, due to the hygroscopic nature of CNCs, the structural colored material changes and may be irreversibly damaged at high relative humidity. Thus, moisture protection is essential in such settings. In this work, hygroscopic CNC‐based films are protected with a bioinspired synthetic plant cuticle; a strategy already adopted by real plants. The protective cuticle layers altered the reflected colors to some extent, but more importantly, they significantly reduced the water vapor permeance by more than two orders of magnitude, from 2.1 × 107 (pristine CNC/GLU film) to 12.3 × 104 g µm m−2 day−1 atm−1 (protected CNC/GLU film). This expands significantly the time window of operation for CNC/GLU films at high relative humidity.

High rate of water loss and rapid respiration cause significant decrease in firmness, turgor, crunchiness, and weight loss resulting in rapid postharvest quality deterioration and shorter shelf-life of fruits and vegetables. Wax-based coatings can effectively maintain postharvest quality of these perishables, and enhance their shelf life. However, petroleum-based synthetic waxes are harmful for consumers' health and environment. Carnauba wax is a plant-based natural wax, extracted from the leaves of the Brazilian palm tree (Copernicia prunifera). Carnauba wax is a GRAS substance, and recognized as a food additive (E 903), which is highly hydrophobic in nature. This review is a comprehensive account of extraction of carnauba wax, its composition, functional properties, and application in fabrication of films and coatings for packaging/preservation of fruits and vegetables. Coating formulation and film fabrication techniques are also elaborated. Moreover, safety aspects of carnauba wax for food applications are also discussed. Carnauba wax coatings effectively enhance postharvest shelf life by reducing water loss, respiration rate, and maintaining firmness, crunchiness and consumer acceptability for longer duration of numerous fruits like orange, guava, apple, pomegranate, tomato and egg plant. Incorporated of the wax in biopolymer (e.g., starch, chitosan, gelatin, fish protein, glucomannan, etc.) based composite films exhibit excellent moisture, gas and light barrier properties, improve mechanical and thermal stability. This review highlights potential uses of carnauba wax as a natural coating or in biopolymer based composite films for sustainable preservation and packaging of postharvest fruits and vegetables. • Fruits and vegetables are perishable foods with shorter shelf-life. • Wax coating is an effective way to improve their postharvest life. • Carnauba wax-based coating is a natural alternative with high hydrophobicity. • The wax coating reduces water loss and respiration rate in postharvest produce. • Carnauba wax in biopolymer based composite films improves their barrier properties. [ABSTRACT FROM AUTHOR]

This work analyses the impact of lipid addition (beeswax) on the physicochemical, rheological, microstructural, mechanical, and moisture barrier properties of the chitosan/sodium caseinate composite solution. The addition of lipid affects the different parameters but improves the moisture barrier properties of the films in comparison to the films without lipid addition. The addition of lipid influences the rheological and microstructural properties as higher concentration results in more viscous solutions and films with a rough surface and larger droplets size. Film thickness and particle size increased as the concentration of beeswax increased from 0.5% to 1.5% in the film-forming solution. Transparency of the film is also influenced by the addition of lipids in the emulsion but the concentration of other film-forming constituents affects the transparency of the films. Mechanical properties of the films are inversely related to the increase in wax concentration as tensile strength and elongation at breakage decreased as the concentration of wax increased, however, young's modulus has not been affected. Biodegradable edible films with improved moisture barrier and tensile properties are preferable in the food packaging industry as these can help in enhancing the package quality and shelf stability of foods especially mangoes, strawberries, bananas, and citrus fruits. [ABSTRACT FROM AUTHOR]

Barrier materials are crucial in preserving product quality, safety and longevity across numerous applications, thereby contributing to sustainability, reducing waste and advancing technology. Among these materials, cellulose nanomaterials (CNs) have emerged as promising alternatives for traditional petroleum-based polymers. However, the wide range of sources and the different methods used to isolate and process CN-based materials can result in significant variations in moisture and oxygen barrier performance. In this review, we provide an in-depth discussion on the latest advancements in CN-based green barrier materials. We begin by offering a critical assessment of the barrier performance of CNs, both in their isolated form and when combined as hybrid materials. This includes their applications as standalone films, fillers and coatings in nanocomposites. This review also covers the influence of the isolation process and the stages of film formation on barrier efficacy. We further discuss the implications of the recycling process on barrier properties of CN-based materials, drawing a connection between barrier characteristics and the product's end-of-life. We conclude by highlighting the significant developments over the past five years, the present challenges, and the prospective future of CN-based materials in barrier applications. [Display omitted] [ABSTRACT FROM AUTHOR]

We describe here the fabrication, characterization, and properties of tough bioplastics made of a babassu oil-based acrylic polymer (PBBM), hemicellulose xylan grafted with PBBM chains, and carnauba wax (CW). The plastic was primarily designed to obtain bioderived materials that can replace low-density polyethylene (LDPE) in certain food packaging applications. To obtain plastic, the radical polymerization of an original babassu oil-based acrylic monomer (BBM) in the presence of xylan macromolecules modified with maleic anhydride (X-MA) was conducted. The polymerization resulted in a material (PBBM-X) mostly consisting of highly branched PBBM/X-MA macromolecules. PBBM-X has a glass transition of 42 °C, a storage modulus of 130 MPa (at 25 °C, RT), and a Young’s modulus of 30 MPa at RT. To increase the moduli, we blended PBBM-X with carnauba wax, a natural material with a high modulus and a melting temperature of ~80 °C. It was found that PBBM-X is compatible with the wax, as evidenced by the alternation of the material’s thermal transitions and the co-crystallization of BBM side alkyl fragments with CW. As a result, the PBBM-X/CW blend containing 40% of the wax had a storage modulus of 475 MPa (RT) and a Young’s modulus of 248 MPa (RT), which is close to that of LDPE. As polyethylene, the PBBM-X and PBBM-X/CW bioplastics have the typical stress-strain behavior demonstrated by ductile (tough) plastics. However, the bioplastic’s yield strength and elongation-at-yield are considerably lower than those of LDPE. We evaluated the moisture barrier properties of the PBBM-X/(40%)CW material and found that the bioplastic’s water vapor permeability (WVP) is quite close to that of LDPE. Our bioderived material demonstrates a WVP that is comparable to polyethylene terephthalate and lower than the WVP of nylon and polystyrene. Taking into account the obtained results, the fabricated materials can be considered as polyethylene alternatives to provide sustainability in plastics production in the packaging areas where LDPE currently dominates.

Summary: This research aimed to improve moisture barrier and functional properties of genipin‐crosslinked chitosan/astaxanthin film by heat curing. The effect of heat curing (25, 80 and 105 °C) on film properties was investigated by measuring water vapour permeability (WVP), contact angle, tensile strength (TS), elongation at break (EAB), Young's modulus (YM), opacity, chemical structure and antioxidant activity. Results showed that genipin‐crosslinked chitosan/astaxanthin film and heat cured at 105 °C (CAG‐105) have the lowest (P < 0.05) WVP value which decreased by 55% while a contact angle increased from 50.2° to 74.6°, when compared to CAG‐25 film. Heat curing affected the chemical‐crosslinked interaction between chitosan and genipin with the establishment of new chemical bonds, leading to the improvement of TS and YM by 55% and 42%, respectively, for CAG‐105 film. However, EAB and antioxidant activity of the CAG‐105 slightly decreased. Moreover, heat curing changed the colour of genipin‐crosslinked chitosan/astaxanthin film from light brown to reddish brown and increased the film opacity which can lower light transmission through the film. The developed film not only had better water barrier, TS and YM but, due to its opacity, could also provide light protection, and thus would be appropriate for packaging material of foods that degrade when exposed to moisture or light. [ABSTRACT FROM AUTHOR]

The goal of this research was to understand how firefighter protective suits perform in different operational environments. This study used a sweating guarded hotplate to examine the effect of environmental temperature (20–45°C) and relative humidity (25–85% RH) on evaporative heat loss through firefighter turnout materials. Four firefighter turnout composites containing three different bi-component (semi-permeable) and one microporous moisture barriers were selected. The results showed that the evaporative resistance of microporous moisture barrier systems was independent of environmental testing conditions. However, absorbed moisture strongly affected evaporative heat loss through semi-permeable moisture barriers coated with a layer of nonporous hydrophilic polymer. Moisture absorption in mild environment (20–25°C) tests, or when testing at high humidity (>85% RH), significantly increased water vapor transmission in semi-permeable turnout systems. It was also found that environmental conditions used in the total heat loss (THL) test (25°C and 65% RH) produced moisture condensation in bi-component barrier systems, making them appear more breathable than could be expected when worn in hotter environments. Regression models successfully qualified the relationships between moisture uptake levels in semi-permeable barrier systems and evaporative resistance and THL. These findings reveal the limitations in relying on THL, the heat strain index currently called for by the NFPA 1971 Standard for Structural Firefighter personal protective equipment, and supports the need to measure turnout evaporative resistance at 35°C (Ret), in addition to THL at 25°C. [ABSTRACT FROM AUTHOR]

Nowadays, resource efficiency is critical for sustainability. This study investigates the use of high moisture barrier plastic casing as an alternative to traditional cellulose casing in sausage production, based on various innovative initiatives for sausage production by many casing suppliers. The plastic casing significantly reduces water loss during processing, leading to positive environmental and economic impacts. Various parameters including texture, shelf life, color analysis, and casing durability were examined. Results show no significant differences in chemical composition between products with plastic casing and those with traditional casing. However, texture analysis revealed differences, particularly in adhesiveness and springiness. Significant color variations were also observed. The study anticipates substantial water savings and energy conservation through the use of plastic casing, with a projected reduction in water consumption of 3,680 tons per month and energy savings of 1.36 kWh/ton through oven program optimization. This study demonstrates that the high moisture barrier polyamide casing can be used as an alternative. [ABSTRACT FROM AUTHOR]

Background: Encapsulation is commonly used to protect probiotics against harsh stresses. Thus, the fabrication of microcapsules with special structure is critical. In this work, microcapsules with the structure of S/O/W (solid-in-oil-in-water) emulsion were prepared for probiotics, with butterfat containing probiotics as the inner core and with whey protein isolate fibrils (WPIF) and antioxidants (epigallocatechin gallate, EGCG; glutathione, GSH) as the outer shell., Results: Based on the high viscosity and good emulsifying ability of WPIF, dry well-dispersed microcapsules were successfully prepared via the stabilization of the butterfat emulsion during freeze-drying with 30-50 g L -1 WPIF. WPIF, WPIF + EGCG, and WPIF + GSH microcapsules with 50 g L -1 WPIF protected probiotics very well against different stresses and exhibited similar inactivation results, indicating that EGCG and GSH exerted neither harm or protection on probiotics. This significantly reduced the harmful effects of antioxidants on probiotics. Almost all the probiotics survived after pasteurization, which was critical for the use of probiotics in other foods. The inactivation values of probiotics in microcapsules were around 1 log in simulated gastric juice (SGJ), about 0.5 log in simulated intestinal juice (SIJ), and around 1 log after 40 days of ambient storage., Conclusion: Dry S/O/W microcapsule, with butterfat containing probiotics as the inner core and WPIF as the outer shell, significantly increased the resistance of probiotics to harsh environments. This work proposed a preparation method of dry S/O/W microcapsule with core/shell structure, which could be used in the encapsulation of probiotics and other bioactive ingredients., (© 2023 Society of Chemical Industry.)

[Display omitted] • Zn-Al composite oxide-based antibacterial moisture barrier thin film was developed. • Refractive index and transmittance changed linearly with Zn ratio in the deposited film. • Films with different Zn content were highly antibacterial against E. coli and S. aureus. • Zn-Al composite oxide surface was mold-free after the mold tests. • Proposed film can be applied to functional optical films. This study investigated Zn–Al composite oxide-based antibacterial moisture barrier film for flexible electronic devices using PEALD. Diethyl zinc and trimethyl aluminium precursors were used to deposit Zn and Al atoms, respectively, which were oxidised using oxygen plasma. The transmittance, refractive index, and water vapour transmission rate (WVTR), as well as the antibacterial and antifungal properties of the Zn–Al composite oxide thin films with different Zn/Al ratios were evaluated comparatively. The deposited films exhibited a linear change in refractive index from 1.66 to 1.87 and transmittance from 87.8 to 78.3% with an increase in the Zn ratio from 24.7 to 100. Furthermore, the film with a Zn ratio of 10.4 showed the best WVTR of 9.06 × 10−4 g/m2/day. In addition, the antibacterial and antifungal properties of the Zn–Al composite oxide thin films were evaluated through antibacterial and mould growth tests, respectively. All samples exhibited high antibacterial activities of 6.2 and 4.7 against Escherichia coli and Staphylococcus aureus , respectively, and no mould growth occurred on the surfaces of the Zn–Al composite oxide films. The antibacterial moisture-barrier films developed in this study can apply such as protecting human health, next-generation flexible touch displays and functional optical films. [ABSTRACT FROM AUTHOR]

• Beeswax (BW) in biopolymer-based films enhances their barrier and tensile features. • BW coating is capable of tuning the release of bioactives from the polymer matrices. • BW coating is an effective approach to prolong the shelf-life of climacteric fruits. • Pseudo-bilayer concept is introduced to design new BW-based biodegradable materials. • Hydrophobic BW-based packaging is feasible for application on high moisture food. Recently, the design and fabrication of bio-inspired superhydrophobic materials using natural lipid additives such as beeswax (BW) have aroused great attention in food packaging as they can minimize the transfer rate of water molecules and have effective moisture barriers. This review discusses the recent progress in the design and fabrication of BW-containing edible films/coatings (e.g., emulsion and blend films, bilayer materials, bionanocomposites, and antimicrobial materials) and their potential applications on the postharvest life and quality attributes of various fruits. Incorporation of BW into polysaccharides- and proteins-based emulsion films effectively improved their hydrophobicity, water vapor, and UV/visible light barrier properties, as well as the film tensile properties. The addition of nanoparticles to BW-based polymeric matrices often results in improved physico-mechanical properties. BW coatings have been also applied to prolong the shelf-life of various climacteric fruits, however, optimization of the wax concentration can be further investigated to develop targeted food storage systems. [ABSTRACT FROM AUTHOR]

Hybrid organic-inorganic metal halide perovskite solar cell (PSC) technology is experiencing rapid growth due to its simple solution chemistry, high power conversion efficiency (PCE), and potential for low-cost mass production. Nevertheless, the primary obstacle preventing the upscaling and widespread outdoor deployment of PSC technology is the poor long-term device stability, which stems from the inherent instability of perovskite materials in the presence of oxygen and moisture. To address this issue, in this work, we have synthesized a series of thermoplastic polyurethanes (TPUs) through a rational design by utilizing polyols having different molecular weights and diverse isocyanates (aromatic and aliphatic). Thorough characterization of these TPUs (ASTM and ISO standards) along with structure-property relationship studies were carried out for the first time and were then used as the encapsulation material for PSCs. The prepared TPUs were robust and adhered well with the glass substrate, and the use of low temperature during the encapsulation process avoided the degradation of the perovskite absorber and other organic layers in the device stack. The encapsulated devices retained more than 93% of their initial power conversion efficiency (PCE) for over 1000 h after exposure to harsh environmental conditions such as high relative humidity (80 ± 5% RH). Furthermore, the encapsulated perovskite absorbers showed remarkable stability when they were soaked in water. This article demonstrates the potential of TPU as a suitable and easily scalable encapsulant for PSCs and pave the way for extending the lifetime and commercialization of PSCs.

This work focuses on the shelf-life of moisture-sensitive products, particularly intermediate-moisture (IMFs) and low-moisture foods (LMFs), which can support the needs of vulnerable populations. Deterministic and probabilistic engineering methodologies, i.e., ignoring and considering the variability of parameters used in calculations, respectively, were compared when selecting the initial water activity of product mix components or the packaging materials achieving the shelf-life necessary to reach consumers with safe and high quality products, and when filling packages with the declared net weight. This document presents detailed examples and reviews published computational tools developed to solve these cases. The application of probabilistic engineering and computer supported tools can help developers optimize the product formulation and packaging material selection to reduce food waste by increasing the probability that products will have the shelf-life necessary to be stored and distributed to reach all consumers, and particularly at-risk populations and those affected by natural or man-made disasters. Undoubtedly, the need for food waste reduction is now a key responsibility for food producers and consumers. The lack of sufficient food creates social and economic instability, and this is an unfavorable situation for the growth of the food industry. Food waste also increases the cost of products, particularly when retailers and consumers demand a refund for a product that did not meet the shelf-life declared or at least expected for the product. This work reviews computer supported probabilistic engineering tools to reduce the waste of products with a shelf-life controlled by the product formulation and the moisture barrier properties of the packaging material. • Computer-supported probabilistic formulation/packaging selection reduces food waste. • Probabilistic formulation/packaging meets the desired quality with high confidence. • Net fill weight compliance optimization reduces production costs. [ABSTRACT FROM AUTHOR]

The current packaging materials market is dominated by petrochemical-derived, single-use, and inexpensive plastics that are incredibly stable in the environment. After their sole use, only a small fraction is recycled, with the remaining ending up in landfills, incineration facilities, or littered in the environment threatening the health of our environment. Nature-derived, compostable, and biodegradable polymers are appealing alternatives to replace single-use plastics in packaging and coating applications. However, most sustainable polymer alternatives cannot compete with traditional plastics in key packaging property attributes, such as gas and moisture barrier properties. Thus, there is a dire need to design chemistries and processing technology to enhance the barrier properties of sustainable polymer systems. In this review, we conducted a critical and comprehensive summary of the important and impactful contributions on improving the gas and moisture barrier properties of sustainable polymer systems for packaging applications. The work highlights signature accomplishments on the effect of tuning the microstructure, surface energy, morphology, and self-assembly of polymers on the gas and moisture barrier properties of the resulting films and coatings. The recent developments in designing multiphase and multicomponent systems and the impact of nanotechnology on barrier properties of sustainable packaging plastics are emphasized. [ABSTRACT FROM AUTHOR]

One of the primary constituent layers of fire protective clothing is a flame-retardant, waterproof and breathable moisture barrier, which permits the outward transfer of perspiration from the firefighter's body, while barring the inward entry of water. The introduction of a chemical and biological resistant functionality can greatly enhance the overall applicability of fire protective clothing. In the present work, a chemical & biological resistant waterproof breathable flame retardant moisture barrier fabric was prepared by laminating a biaxially stretched microporous expanded polytetraflouroethylene (ePTFE) membrane with Activated Carbon Fabric using a hot melt reactive breathable polyurethane adhesive. The developed laminate was found to exhibit an excellent balance of waterproofness (23 kPa) and breathability, which was quantified in terms of water vapour transmission rate (WVTR) and water vapour resistance (Ret). High values of WVTR, 1.1025 × 104 ± 9.8×101 g/m2/day complimented with exceptionally low values of Ret, 2.9 m2Pa/W are indicative of its high degree of breathability. Vertical flammability tests clearly revealed the exceptional flame resistance offered by the laminate, where after-flame, after-glow or melt-dripping was not observed and the char length was ∼4.2 cm. Further, the laminate exhibited requisite degree of protection against biological and chemical warfare (CW) agent with no breakthrough of the CW agent being perceived within the time frame of 24 h. The excellent combination of flame retardancy, breathability, waterproofness, chemical and biological protection, bestows the laminate excellent potential for usage as moisture barrier in fire protective clothing applications. [ABSTRACT FROM AUTHOR]