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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]

Camellia oleifera shells (COS) are commonly discarded as an agricultural by-product. Effective utilization of COS can not only reduce environmental pollution but also enhance the value of the tea-oil industry. The unique composition of COS, with high hemicellulose and low cellulose content, makes it suitable for the production of film materials. In this study, COS holocellulose (COSH) was isolated and treated with four different types of dilute acids (15 % acetic acid, gallic acid, citric acid, and 0.5 % sulfuric acid, 1–24 h, 75°-105 °C) to produce barrier films. Among these, citric acid treatment resulted in the strongest and toughest film. By incorporating a brief ultrasonic pretreatment (15 min, 300 w) prior to the citric acid reaction, translucent films were achieved with impressive mechanical properties, showing tensile strength, Young's modulus and elongation at break up to 75.72 MPa, 3306.11 MPa and 8.01 %, respectively. Through a comprehensive analysis of the structure-property relationships, it was discovered that the combined effects of ultrasonic and citric acid treatments disrupted the integrated holocelluose fiber structure and facilitated the formation of a robust hydrogen bond network during the film preparation process. The resulting films exhibited enhanced water vapor barrier properties, antioxidant capacity, and complete decomposition in soil, suggesting the potential application as wraps for fresh fruits. [Display omitted] • Treatment of C. oleifera shell holocellulose with dilute acids to produce robust films • Citric acid treatment resulted in the toughest films with a tensile strength >70 MPa • Incorporation of ultrasonic pretreatment further improved film elasticity • Holocellulose defibrillated and reformed strong barrier films via H-bonding • The translucent films served as compostable wraps for fresh 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]

A simple solution casting approach was used to obtain transparent and flexible poly(methyl methacrylate) (PMMA) films incorporated with 1 – 4% by weight amorphous magnesium carbonate nanoparticles. Optical transparency was retained in visible wavelengths, while transmittance in the UV-B region was reduced by 22% at 310 nm and 58% at 256 nm with the addition of 4 wt. % nanoparticles. Furthermore, the incorporation of the nanoparticles was shown to provide protection for the films under UV-C irradiation (254 nm wavelength, 5 mW cm−2), with the amount of UV degradation decreasing with increasing concentration of nanoparticles. Films with incorporated nanoparticles were also shown to be able to retain adsorbed moisture much better than neat PMMA films; whereas neat PMMA films did not retain moisture, approximately 50% of the adsorbed moisture was retained in films containing 4 wt. % nanoparticles. These enhanced properties of PMMA are of great interest in applications such as flexible and transparent screens for personal electronic devices that require protection from both UV light and moisture. [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.)

The dampness of building envelopes not only poses a great threat to the use and safety of building structures, but also the long-term dampness will affect the aesthetics of the building maintenance structure and even the degradation of indoor air quality, so it is more vulnerable to the offshore. The calculation and simulation of the section strength of the moisture barrier layer of the building envelope structure are of great significance. Based on the analysis of previous research results, this paper takes a moisture-proof layer of wedge-shaped envelope structure as an example, establishes a finite element model through simulation software, simulates the stress loading process and analyzes the stress-strain curve; in the study of steel bar size and steel type After the influence of parameters such as hoop index, concrete strength, water-cement ratio, and reinforcement ratio on the section strength of the moisture-proof layer, combined with the non-linear least-squares method, the shear resistance, bending resistance and compression resistance of the moisture-proof layer of the envelope structure are analyzed, a multi-factor calculation model of strength established. The validity of the model is verified by comparison with experimental data, and it provides a reference for further research. [ABSTRACT FROM AUTHOR]

• UV light was identified as one of the sources causing the degradation of polymer solar cells. • UV cut filters can improve the lifetime of the polymer solar cells. • Thin Ag capping layer can improve the stability. The degradation of the polymer solar cells in the outdoor condition was studied. It was found that the devices with normal structure (ITO/PEDOT:PSS/PBDTTT-EFT:PC 71 BM/ZrO x /Al) show better stability than those with inverted device structure (ITO/ZnO/PBDTTT-EFT:PC 71 BM/MoO 3 /Ag). PBDTTT-EFT is poly[4, 8-bis(5-(2-ethylhexyl) thiophen-2-yl) benzo [1,2-b;4,5-b'] dithiophene-2, 6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno [3,4-b]thiophene-) −2-carboxylate-2-6-diyl)] and PC 71 BM is [6,6]-phenyl-C71-butyric acid methyl ester. The major cause of degradation was attributed to the ultraviolet (UV) part of the sunlight. When the UV filter with cut-off wavelength of 400 nm was used to protect the device, the decay rate was improved by 50 times and the protected device retains 95% of their initial power conversion efficiency after 13 days outside. In the meanwhile, the decay of device fabricated by toluene was found 8 times faster than device by chlorobenzene. Thin 20 nm of Ag capping layer can further improve the stability. Degradation under water immersion indicates that the major effect of Ag is to protect against the residual moisture inside the encapsulation. [ABSTRACT FROM AUTHOR]

In this study, the growth characteristics and film properties of the atomic layer deposition (ALD) of Al 2 O 3 are systemically identified using various oxidants (i.e., H 2 O, H 2 O 2 , CH 3 COOH, and O 3). Among these reactants, ALD Al 2 O 3 grown by using H 2 O 2 exhibits excellent density and refractive index, which may be attributed to the large number of hydroxyl groups on the surface after reactant exposure, forming a dense film. When CH 3 COOH is used for the ALD Al 2 O 3 oxidant, poor quality films with relatively small density and refractive index and high carbon impurities were deposited possibly due to the formation of carbon species, such as carbonates or formates. In the case of ALD Al 2 O 3 that uses O 3 , the film property is barely changed with the growth temperature increase because the reaction between trimethylaluminum and O 3 is incomplete in low-temperature region (<150 °C), and impurities that are difficult to eliminate remain. Among these Al 2 O 3 films prepared by using different oxidants, H 2 O 2 -grown Al 2 O 3 at 120 °C exhibits the lowest water vapor transmission rates, ca. 2.7 × 10−4 g/m2⋅day, owing to the high density of the film with negligible amount of impurities. Therefore, ALD Al 2 O 3 using H 2 O 2 is expected to be a promising encapsulation layer for future flexible OLED devices with excellent characteristics. [ABSTRACT FROM AUTHOR]

We investigated the moisture barrier properties of SiO 2 layers deposited via plasma-enhanced atomic layer deposition (PE-ALD) for encapsulation of an organic light-emitting diode (OLED). First, the growth characteristics and film properties of PE-ALD SiO 2 using diisopropylamino silane (DIPAS) and O 2 plasma were investigated. The film properties were significantly improved by applying proper O 2 plasma treatment. The O 2 plasma treatment increased the adsorption of the metal precursor by creating sufficient hydroxyl groups on the substrate. We not only increased the adhesion between the thin film and the polymeric substrate through O 2 plasma treatment before the deposition process but also formed a high-density thin film, resulting in excellent moisture barrier properties. Consequently, the water vapor transmission rate (WVTR) was significantly reduced to 7.73 × 10−3 g/m2∙day, which was 10 times lower than that of a control sample. These newly developed methods can be applied to other metal oxides, such as Al 2 O 3 and ZrO 2 , for OLED encapsulation with a low WVTR. [ABSTRACT FROM AUTHOR]

[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.

The use of clay filler materials in dispersion coatings is a well-established method to provide improved barrier properties to the coated paper substrate, in particular lowering the water vapour transmission rate (WVTR) through the coating. In this paper we demonstrate the use of small spherical silica particles (È100-220 nm) as an additive to a clay-latex coating formulation is able to provide further improvements to the barrier properties, when compared to the equivalent silica-free coatings. A significant decrease in both the water vapour transmission rate and the direct water uptake of water (Cobb120 wettability test) is observed for coatings containing as little as 1% silica additive.

In this study, a synthesized polymerizable quaternary ammonium salt (PQAS-18) was intercalated into inorganic sodium montmorillonite (Na-MMT) as an organic modifier via cationic exchange. Afterward, a novel organic–inorganic hybrid material was prepared through in situ UV-curing technology and combined with a polymer matrix based on polybutadiene dimethacrylate (PBDMA). PQAS-18 fixed the crosslinked network due to its double bond, thereby leading to firm bonding between the polymer matrix and organoclay; moreover, our study showed homogeneous dispersion of the lamellar structure in the polymer matrix. X-ray diffraction proved that the distance between Na-MMT layers increased, and water vapor transmission measurement showed that the moisture barrier property of cured hybrid film was remarkably improved. [ABSTRACT FROM AUTHOR]

Highlights • We introduce class-II-type high-performance hybrid coating (NS-EP hybrid) composed of a surface-modified nanosilica and a thermo-curable epoxy matrix. • The NS-EP hybrid exhibits excellet moisture barrier performace as well as robust mechanical property. • The OLED device is encapsulaed with the NS-EP hybrid coating, and thus shows considerably extended lifetime. Abstract We report the development of a class-II-type hybrid coating (NS-EP hybrid) composed of surface-modified nanosilica (NS) as the filler and a thermo-curable epoxy polymer (EP) as the matrix. NS is synthesized using a hydrolytic sol-gel process; its hydroxyl surface is rendered cross-linkable using glycidyl ligands to ensure homogeneous dispersion and optimal hybridization with the EP matrix. The NS-EP hybrid shows high optical transparency, enhanced mechanical properties, and improved moisture barrier performance. Further, we discuss the physical properties of the hybrid with respect to the NS content. To study the applicability of the hybrid as a high-performance barrier material in practical applications, an actual OLED device is encapsulated using the hybrid. [ABSTRACT FROM AUTHOR]

Abstract In this work, we employ atomic layer deposition (ALD) to form Al 2 O 3 layer as an encapsulant for perovskite solar cells (PSCs). Al 2 O 3 layer deposited at temperature as low as 95 °C achieves water vapor transmission rate (WVTR) of 1.84 × 10−2 g m−2 d−1 at 45 °C–100%RH when thermal ALD is used. In order to test the moisture barrier capability of Al 2 O 3 layer for PSCs, mesoporous perovskite devices, with spiro-OMeTAD or PTAA as hole transport layer (HTM) encapsulated by 50 nm Al 2 O 3 film, are exposed to 65 °C–85%RH for 350 h and their stabilities are monitored. We find that the color of perovskite does not change after 350 h of exposure regardless of the type of HTM used. With regards to Th-ALD encapsulated devices, PTAA based PSCs experienced a smaller power conversion efficiency (PCE) drop than spiro-OMeTAD based PSCs after thermal stress at 65 °C. This is due to the presence of pinholes within spiro-OMeTAD layer after thermal stress which are not observed in PTAA. Finally, we successfully achieve excellent durability test results for mesoporous (HC(NH 2) 2 PbI 3) 0.85 (CH 3 NH 3 PbBr 3) 0.15 /PTAA devices encapsulated by 50 nm Al 2 O 3 with less than 4% drop in PCE after 7500 h (> 10 months) of exposure to 50%RH under room temperature. Graphical abstract Synopsis: This research focused on the method to enhance the stability of perovskite solar cells via Al 2 O 3 thin film encapsulation. Additionally, degradation mechanism is investigated during ALD process. fx1 Highlights • The WVTR values of 50 nm Al 2 O 3 layers is 1.84 x 10−2 g m−2 d−1 at 45 °C–85 %RH. • PTAA is more stable than spiro-OMeTAD during ALD process. • Pinholes are formed within spiro-OMeTAD layer under thermal stress. • PTAA-based devices experiences less than 4% drop after 7500 h of 50 %RH at room temperature. [ABSTRACT FROM AUTHOR]

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]

A plasma-enhanced chemical vapor deposition (PECVD) was developed for the growth of highly conformal carbon-doped silicon nitride (SiCN) films with enhanced barrier properties drawing on tunable carbon contents, k-values, and wet etch rates (WER). Trisilylamine (TSA) was used as the main precursor and hexane was used as a hydrocarbon-containing additive precursor for carbon doping. At low deposition temperatures ≤ 400 °C, we show that this PECVD process leads to the formation of SiCN films with good conformality of approximately 91% over high aspect ratio trench nanostructures (4.2:1) with a growth rate of ~2.5 (Å/cycle). In particular, the role of TSA and hexane precursors on the film growth mechanism and the k-values, and WER in the composite structures has been explored. The precursors were introduced pulse-wise into the reaction chamber while plasma was excited. The WER of the film was evaluated in a buffered hydrofluoric acid etchant. The k-value and carbon concentration varied depending on the TSA/hexane supply time in the ranges of 7–4.5 and around 6–40%, respectively. Analysis showed that the hexane precursor improved the WER of deposited SiCN films by more than a factor of 100 compared to when only TSA was used. The SiCN film with a thickness of 5.0 nm exhibited excellent prevention of moisture diffusion into the device. Furthermore, the step coverage was improved to equivalent conformality of the plasma-enhanced atomic layer deposition (PEALD) by modifying the supply method of the Si and carbon precursors and the moisture barrier property was secured with thicknesses of <10 nm. In particular, the Si and carbon precursors are biased to maximize the process margin and control the film characteristics, where tuning can be easily implemented. [ABSTRACT FROM AUTHOR]

We report the facile fabrication of transparent and high-performance moisture barrier material (SC nanocomposite) using surface-modified bentonite clay (SC) as nanofiller and glycidyl silane as a surface-modifier/binder via simple, cost-effective and mass-producible process. SC is synthesised using a base-catalysed sol-gel process; their hydroxyl surfaces are decorated with glycidyl ligands to endure the densely stacked structure and high clay content in the final nanocomposite. The SC nanocomposite barrier exhibits high optical transparency (>90), dense multi-stacked clay structure, and considerably enhanced moisture barrier performance. We discuss the fabrication and physical properties of the SC nanocomposite. To assess the applicability of the nanocomposite as a high-performance barrier material in practical applications, typical organic light-emitting devices are encapsulated, and their lifetime is evaluated. [ABSTRACT FROM AUTHOR]

In this study, hybrid nanocomposite films were prepared by a sol-gel method. Al 2 O 3 particles of 100 nm diameter were mixed with small SiO 2 nanoparticles of 10 nm in a coating solution. After coating onto a plastic sheet, the water vapor transmittance rate (WVTR) was reduced from 12.2 to 0.15 g m −2 day −1 . However, due to the particle aggregation in the Al 2 O 3 /SiO 2 system, pore size of the barrier coating remained constant despite the Al 2 O 3 /SiO 2 ratio. To avoid particle aggregation and to reduce the WVTR, vanadium oxide was added in the coating solution to suppress the aggregation of nanofillers via dehydroxylation. From BET analysis, the addition of vanadium oxide resulted in a smaller pore size to further inhibit water vapor penetration. The WVTR was lowered to 0.095 g m −2 day −1 at a relative humidity of 100%, corresponding to an improvement of 99.2% compared to that of the pristine PET. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the effects of the plasticizer type (sorbitol or glycerol) and lipid concentration (oleic acid or oleic acid-beeswax mixtures) on sodium caseinate (NaCas)-based films and to investigate how, and to which extent, these parameters are affecting the technofunctional properties of NaCas-based films. Additionally, we intended to demonstrate the antioxidant potential of quercetin as a component of the described formulations. Films prepared from the different composed emulsions were characterized in terms of selected packaging-relevant properties. The results showed that the type of plasticizer and the lipid concentration had significant effect on the technofunctional properties of NaCas-based films. Contact angle measurement and evaluation of the SFE revealed rather hydrophilic than hydrophobic surfaces. Determination of the WVTR showed a significant influence (p ≤ 0.05) of the type of plasticizer towards WVTR. WVTR was clearly decreased for sorbitol-plasticized films. On the contrary, the influence of the lipid concentration was also significant (p ≤ 0.05), but not as clear as the plasticizer effect. However, at 10% (w/w) beeswax (BW) addition, there was a sharp drop in WVTR visible for glycerol-plasticized films. Measurement of the OP did not yield as clear results as suggested in preliminary test series. Although, we did not conduct systematic studies regarding the effect of the antioxidant towards the OP we showed the antioxidant potential of the described compositions. Results for the mechanical performance showed a significant influence (p ≤ 0.05) of the type of plasticizer and lipid concentration. YM and TS values were clearly higher for sorbitol-plasticized films whereas E% values were lower for sorbitol-plasticized films. Regarding the effect of the lipid concentration on the mechanical performance, no apparently visible trend could be identified. Light transmittance measurement revealed that in terms of UV-absorptivity at wavelengths between 300 nm and 400 nm, the incorporation of quercetin led to promising barrier properties against UV-light. [ABSTRACT FROM AUTHOR]

This study presents an experimental investigation of sealed seams performance of two types of nonwoven fireproof fabrics laminated with bicomponent and hydrophilic membrane, which are used for moisture barrier layer in firefighters clothing. Seam strength in longitudinal and cross direction and resistance to water penetration were determined for investigation of quality of sealed seams with thermoplastic polyurethane tape. Determining the efficiency of sealed seams, optimal sealing parameters (temperature, sealing speed and quill pressure) were identified in order to achieve good seam performance. The experimental relations and empirical equations for the seam strength and resistance to water penetration determined in this research can be used to predict efficiency of seams quality applying different parameters of seam sealing process. DOI: http://dx.doi.org/10.5755/j01.ms.20.2.3396

Polydimethylglutarimide (PMGI), a photosensitive positive type resin used in photoresists, is shown to be an effective moisture barrier for mitigating the effect of humidity on the sensitivity of Pt-AlGaN/GaN Schottky diodes for hydrogen detection. The maximum relative current change observed in PMGI-encapsulated diodes forward biased at 1.3 V and exposed to 500 ppm of dry or humid H2 is identical within experimental error over the temperature range 25 °C–300 °C and peaks at 200 °C in both cases ( 4.4\times 10^6 % increase compared with the current under N2 ambient). Unencapsulated diodes exhibit a decrease of approximately one ninth of the current signal for detection of 500 ppm of H2 in the presence of water. The PMGI is easily spun-on to the sensors, and does not degrade until temperatures of 335 °C or higher, making it a suitable moisture barrier for most hydrogen sensing applications. [ABSTRACT FROM PUBLISHER]

One of the biggest issues with GaN-based hydrogen sensors is their sensitivity to humidity in the ambient. We demonstrate that encapsulation of Pt-AlGaN/GaN Schottky diode with poly(methyl methacrylate) (PMMA) provides effective mitigation of the effects of water. Without PMMA encapsulation, the absolute current signal for detection of 500 ppm of H2 was decreased by a factor of 8 in the presence of water. By sharp contrast, encapsulated diodes show no decrease in response in the presence of water. The relative current changes are of the order 2.8 \times 10^5 % when 500 ppm H2 is introduced to the surface of bare or PMMA encapsulated diodes in the absence of water or to encapsulated diode in the presence of water. Detection limits of ~ 100 ppm H2 (0.01% by volume) were obtained with standard forward bias detection mode at 1.3 V. [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]