Strong Barrier Properties Research Articles

Development of fish gelatin film for anti-fogging mushroom packaging

Mushrooms are extremely perspiring and transpiring commodities. The commonly used plastic films for packaging fresh mushrooms have lower water vapour permeability compared to the rate at which mushrooms transpire, resulting in excessive moisture accumulation inside the package which leads to fogging. This study aimed to investigate the properties of a fish scale gelatin-based film and its correlation with antifogging properties. To produce the gelatin-based film, gelatin was extracted from fish scales using chemical pretreatment and thermal denaturation of collagen. A film-forming solution (FFS) was prepared by dissolving 2% (w/v) gelatin in a solvent, with the addition of glycerol. The solution was then cast to form the film, which underwent tests for mechanical strength, thermal behaviour, barrier properties, and antifogging performance. The resulting film (G-Gly) exhibited reduced tensile strength (13.21 MPa) but increased elongation at break (82.4%). Differential scanning calorimetry revealed a lower glass transition temperature (59.91 °C) for G-Gly. Both gelatin films displayed high water vapour permeability (1.69–3.09x10-6 g m/m2.day.Pa), preventing condensation. Notably, the G and G-Gly films remained fog-free even under varying temperatures, unlike linear low-density polyethylene film (LLDPE). In conclusion, the gelatin-based films demonstrated strong barrier properties and effective antifogging capabilities, making them suitable for moisture-sensitive commodities like mushrooms.

Potato oxidized hydroxypropyl starch/pectin-based indicator film with Clitoria ternatea anthocyanin and silver nanoparticles for monitoring chilled beef freshness

Potato oxidized hydroxypropyl starch (POHS)/pectin (P) functional and smart beef freshness indicator films were prepared using butterfly pea (Clitoria ternatea) anthocyanin (BA) and silver nanoparticles (AgNPs). BA exhibited significant pH-responsive color changes. BA and AgNPs were evenly distributed within a polymer matrix to create a compatible film with POHS/P. The films containing BA and AgNPs had good UV resistance and maintained strong mechanical strength, barrier properties, and color stability. The color of the indicator film changed from purple to green when exposed to ammonia, with the 1 % POHS/P/BA/AgNPs film showing the most sensitive response. The films also demonstrated strong antibacterial and antioxidant properties. The freshness of beef was monitored using 1 % POHS/P/BA/AgNPs films and was identified as sub-fresh and spoiled on days 4 and 7, respectively. The relationship between the color change of the indicator label and the freshness of chilled beef was established: purple for fresh meat, blue for less fresh meat, and green for spoiled meat. Thus, the new POHS/P/BA/AgNPs film can serve as a smart packaging material to indicate food freshness and extend shelf life. These results suggest that POHS/P/BA/AgNPs films have significant potential as an active and smart food packaging material.

Syntheses of diphenolic resin based anti-corrosion coating material and reinforce its performance through MWCNT-Ag and MWCNT-Ag/PANI nanofillers

In the present work, a novel anti-corrosion coating material was developed using diphenolic resin and multiwalled carbon nanotube (MWCNT) based nanofillers. In this concern, phenylmethylene diphenolic resin (PMD) and its 2-(4-methylbenzyl) oxirane derivative (PMDD) were synthesized using phenol and benzaldehyde. Silver-decorated MWCNT (MWCNT-Ag) and polyaniline (PANI) synthesized on MWCNT-Ag (MWCNT-Ag/PANI) were also fabricated and employed as filler materials to enhance the anti-corrosion performance of PMDD. The resins were analyzed by LC-MS and FT-IR, and the nanofillers were characterized using XRD, SAED, EDX, TEM, and XPS techniques. The synthesized PMD and PMDD and different weight percentages of fillers blended PMDD were coated on the mild steel (MS) sample using doctor blade method. The surface morphology and roughness of the coatings were examined by SEM and AFM analyses. The anti-corrosion ability of the coated samples was assessed by electrochemical impedance spectroscopy (EIS) and salt spray testing (SST). All the results showed an excellent anti-corrosion performance of PMDD by the incorporation of 0.2 wt% of MWCNT-Ag/PANI. Withstanding the 5 wt% NaCl salt spray atmosphere for about 144 h and >460 days in 3.5 wt% NaCl solution reflects its strong barrier property and long-term durability. The cross-linking of resins, blockade of defects by nanofiller and an additional protective layer developed by conductive PANI make the coating material efficient and durable in highly corrosion environments.

Improved barrier performance of Al2O3/polymer multi-layers by insertion of Alucone as hydrolysis inhibition layer and interfacial infiltration

Thin-film encapsulation (TFE) with strong barrier properties is essential for dependable flexible display. Hybrid Al2O3 and polymer multi-layered structures are considered the most promising TFE technology. However, hydrolysis of Al2O3 becomes severe with increased temperature and humidity, threatening the reliability of TFE. In this work, Alucone is introduced in the Al2O3/NEA multi-layers, where the Alucone can serve as a hydrolysis inhibition layer, to improve its reliability. In addition, Al2O3 is permeated into the NEA polymer to further improve the barrier performance of Al2O3/NEA multi-layers. The results show that the insertion of Alucone can inhibit effectively the hydrolysis of Al2O3 in the accelerated test environment. The complete interfacial infiltration of Al2O3 into NEA polymer can further improve the barrier performance. The water vapor transmission rates of (Al2O3/Alucone)3/NEA (named AAN composite films) can reach 0.27 × 10−6 g/m2/day. The barrier performance of AAN composite films remains robust even after bending tests and stability examinations. The OLED encapsulated by the AAN composite films, only less than 10 % brightness decline occurs after 7 days, illustrating that AAN composite films can extend the lifetime of OLED. The results demonstrate that the AAN composite films is anticipated to hasten the commercialization of flexible displays.

Bio-inspired seaweed-based nanocomposite materials with excellent degradability and multifunctional barrier properties for green packaging

The widespread use of petroleum-based plastics brings potential hazards to the ecological environment. In order to solve this issue, the development of biodegradable materials with both high mechanical, barrier performances and food safety is imminent. In this work, a natural nacre-inspired seaweed-based nanocomposite material with the structure of “brick and mortar” is synthesized by rational assembling mica nanosheets in a mixture of glycerol and sodium alginate. The resultant SA/nano-mica film (1 wt% of phlogopite powder) shows high thermal stability (>180 °C) and exhibits great tensile strength of ∼ 16 MPa at ambient condition, surpassing some other reported nanocomposite materials (1.9–14.74 MPa). Meanwhile, the composite can be easily processed into different shapes for packaging applications, which could long-term preserve the freshness of foods owing to their strong ultraviolet (UV) shielding and gas barrier properties (UV transmittance of ∼ 4 % and oxygen transmission rates (100 µm) of ∼ 18.52 cc m−2 day−1 bar−1). Importantly, the material could completely degrade in soil within 15 days. These results indicate the great application prospect of seaweed-based nanocomposite materials in food packaging.

Developing a Prolamin-Based Gel for Food Packaging: In-Vitro Assessment of Cytocompatibility.

Growing environmental concerns drive efforts to reduce packaging waste by adopting biodegradable polymers, coatings, and films. However, biodegradable materials used in packaging face challenges related to barrier properties, mechanical strength, and processing compatibility. A composite gel was developed using biodegradable compounds (prolamin, d-mannose, citric acid), as a coating to increase the oxygen barrier of food packaging materials. To improve gel stability and mechanical properties, the gels were physically cross-linked with particles synthesized from tetraethyl orthosilicate and tetramethyl orthosilicate precursors. Additionally, biocompatibility assessments were performed on human keratinocytes and fibroblasts, demonstrating the safety of the gels for consumer contact. The gel properties were characterized, including molecular structure, morphology, and topography. Biocompatibility of the gels was assessed using bioluminescent ATP assay to detect cell viability, lactate dehydrogenase assay to determine cell cytotoxicity, and a leukocyte stimulation test to detect inflammatory potential. A composite gel with strong oxygen barrier properties in low-humidity environments was prepared. Increasing the silane precursor to 50 wt% during gel preparation slowed degradation in water. The addition of citric acid decreased gel solubility. However, higher precursor amounts increased surface roughness, making the gel more brittle yet mechanically resistant. The increase of precursor in the gel also increased gel viscosity. Importantly, the gels showed no cytotoxicity on human keratinocytes or fibroblasts and had no inflammatory effects on leukocytes. This composite gel holds promise for oxygen barrier food packaging and is safe for consumer contact. Further research should focus on optimizing the stability of the oxygen barrier in humid environments and investigate the potential sensitizing effects of biodegradable materials on consumers.

Effect of glycerol and sorbitol on cellulose-based biodegradable films

Plastics with strong mechanical and barrier properties make them a dominant packaging choice. Their lack of biodegradability, however, with a significant environmental threat, has driven the new generation of biodegradable, renewable, and non-toxic packaging materials. Among several available choices, cellulose is highly suitable due to its strong and stiff molecular structure, biocompatibility, biodegradability, low toxicity, and abundance. However, cellulose-based films possess little flexibility and elongation. This study aims to understand the effect of plasticizers glycerol and sorbitol on cellulose film properties. Cellulose (0.6–0.8 g) was solubilized in 68%ZnCl2 solution and crosslinked with Ca2+ ions (50–400 mM) and plasticizer (5–25% of cellulose) to prepare films and characterized for physical and mechanical properties and soil biodegradability. Results reveal increased tensile strength and elongation at break with the plasticizer amount. The outcome is deemed to provide novel biodegradable packaging films based on cellulose and contribute to reducing plastic pollution.

Development and Characterization of an Edible Zein/Shellac Composite Film Loaded with Curcumin.

The development of functional edible films is promising for the food industry, and improving the water barrier of edible films has been a research challenge in recent years. In this study, curcumin (Cur) was added to zein (Z) and shellac (S) to prepare an edible composite film with a strong water barrier and antioxidant properties. The addition of curcumin significantly reduced the water vapor permeability (WVP), water solubility (WS), and elongation at break (EB), and it clearly improved the tensile strength (TS), water contact angle (WCA), and optical properties of the composite film. The ZS-Cur films were characterized by SEM, FT-IR, XRD, DSC, and TGA; the results indicated that hydrogen bonds were formed among the curcumin, zein, and shellac, which changed the microstructure and improved the thermal stability of the film. A test of curcumin release behavior showed controlled release of curcumin from the film matrix. ZS-Cur films displayed remarkable pH responsiveness, strong antioxidant properties, and inhibitory effects on E. coli. Therefore, the insoluble active food packaging prepared in this study provides a new strategy for the development of functional edible films and also provides a possibility for the application of edible films to extend the shelf life of fresh food.

Development of active packaging films based on collagen/gallic acid-grafted chitosan incorporating with ε-polylysine for pork preservation

Active packaging films (CCG/PL) based on collagen, functionalized chitosan with gallic acid (GA), and ε-polylysine (ε-PL) (different amount of 2.5, 5, and 10 wt%, respectively) were developed to prolong the shelf life of pork stored at 4 °C. Fourier transform infrared analysis indicated that hydrogen bonds had formed between collagen molecules and GA moieties, and there were no strong interactions between polymers and ε-PL. SEM images showed that the cross-sections of CCG/PL films were compact but aggregation of ε-PL occurred when ε-PL content reached 10 wt%. CCG/PL films possessed strong light barrier properties with the UV light transmittance lower than 4% in the range of 200–350 nm. Compared with CC film, the DPPH free radical scavenging rate was significantly increased by 84.35% due to the synergistic effect of GA and ε-PL on antioxidant activity. CCG/PL film containing 5 wt% ε-PL had excellent antimicrobial activity against S. aureus as well as good tensile strength (65.34 MPa). The wrapping of CCG/PL film with 5 wt% ε-PL effectively retarded the lipid oxidation of pork and inhibited the growth of bacterium during the storage time, and the shelf life of pork was prolonged by approximately 5 days than that of pork in polyethylene film.

Synergistic effect of graphene oxide/ ternary Mg-Al-La layered double hydroxide for dual self-healing corrosion protection of micro-arc oxide coating of magnesium alloy

Micro-arc oxidation (MAO) coatings have good corrosion protection properties and can effectively inhibit the corrosion of magnesium alloy surfaces in salt environments. This study aimed to achieve and improve the dual self-healing and corrosion resistance of MAO coating by in-situ growth to form a hybrid coating of vanadate (V2O74-) intercalated a graphene oxide (GO)-doped ternary Mg-Al-La layered double hydroxides (LDHs) (ternary L/G-V coating). The corrosion resistance and self-healing properties were verified by electrochemical experiments and scratch tests. Due to the synergistic effect of the strong barrier properties of GO and LDHs, the ternary L/G-V coating exhibits excellent anticorrosion ability. Interestingly, the ternary L/G-V coating also exhibits self-healing properties when corrosion ions reach the metal/coating interface due to the release of interlayer anionic corrosion inhibitor (vanadate) and rare earth cationic corrosion inhibitor (lanthanum) of LDHs. It makes up for coating defects in time and realizes the dual self-healing function of corrosion protection of MAO coating.

Sustainable and eco-friendly poly (Lactic acid)/cellulose nanocrystal nanocomposite films for the preservation of oxygen-sensitive food

The development of enzymatic browning constitutes one of the key issues in the preservation of highly perishable fresh-cut and oxygen-sensitive fruits such as avocados. This study explored the use of a packaging solution based on PLA/cellulose nanocrystal (CNC) films produced using a solvent-free cast extrusion process with strong oxygen and UV barrier properties to reduce browning in cut avocados and to prolong shelf life. Specifically, the effects of packaging material types (neat PLA vs PLA/CNC nanocomposite) and storage conditions (temperature and time) on discoloration (browning), microbial growth, and shelf life were assessed. Enzymatic browning was visually evaluated and total discoloration (ΔE*) quantified as a function of storage time and temperature to estimate the shelf life of the avocados. Compared with neat PLA, nanocomposite packaging reduced the enzymatic browning more and resulted in additional shelf life extension of 1.3 days at 23 °C and 5.4 days at 4 °C. Both PLA-based films reduced the microbial growth. The potential of sustainable and eco-friendly nanocomposite film to prolong the shelf life of food that is oxygen sensitive is clearly demonstrated.

New ternary deep eutectic solvents with cycle performance for efficient pretreated radiata pine forming to lignin containing cellulose nanofibrils

Ternary deep eutectic solvents (TDESs) as a new class of solvents play a key role in fabrication of lignin containing cellulose nanofibrils (LCNF), however, current work requires a considerable time and thus limits industrial application of TDES. Herein, a novel strategy was proposed to produce lignin containing cellulose nanofibrils (LCNF) by TDESs based on benzyltrimethylammonium chloride (BTMAC), formic acid (FA), and maleic acid (MA). The TDESs could remove 87.80% of lignin and 89.15% of hemicellulose from Radiata Pine while most of the cellulose reserved under optimum pretreatment conditions (TDES = 100 wt%, T = 130 °C, t = 1.5 h). Benefiting from the increase in cellulase accessibility, desired sugar yield of 98.9% was obtained. Moreover, the proposed TDESs could be regarded as a green medium for the production of containing cellulose nanofibrils (LCNF) in which lignin has been esterified. The LCNF displayed a well-individualized structure with a wide size distribution (32.3–146.9 nm), which was closely associated with lignin content. 13C−1H HSQC 2D NMR test was performed to illustrate the molecular − structural features of lignin and polysaccharide in LCNF. In addition, the self-standing LCNF films exhibited excellent UV-blocking, higher thermal stability, and mechanical strength. Most importantly, LCNF films showed strong barrier property to oil and air owing to lower surface free energy and smaller pore structure. Briefly, this work highlights the pretreatment performance of TDESs for cascade utilization of lignocellulosic biomass to high-value products.

In Situ Formation of Microfibrillar PBAT in PGA Films: An Effective Way to Robust Barrier and Mechanical Properties for Fully Biodegradable Packaging Films.

Poly(glycolic acid) (PGA) is a semicrystalline biodegradable polyester with high gas barrier properties. However, due to its poor processability and low ductility, PGA could hardly find applications in the packaging field. Here, a strategy was adopted for in situ generation of high-aspect-ratio flexible microfibrils with strong interface affinity for the PGA matrix. Because poly(butylene adipate-co-terephthalate) (PBAT) possesses impressive ductility, it was selected as the “fibrillar toughening phase” to enhance the ductility of PGA. Moreover, a chain extender was used to enhance the interfacial adhesion between the two polymers. The extrusion blown film technique was then used to develop fully biodegradable PGA/PBAT films with a superior combination of excellent barrier performance and robust mechanical properties. The PBAT phase can in situ form microfibrils under the influence of extensional flow. Simultaneously, the synergetic function of the extensional flow field could effectively promote the motion of the PGA molecular chain to develop an oriented crystalline microstructure. Because of the aligned oriented lamellar crystal of PGA and oriented PBAT fibril structures serving as robust “barrier walls” 60PGA/ADR blown films demonstrated dramatically improved resistance to oxygen and water vapor, with 59 and 44 times lower oxygen permeability and water vapor permeability, respectively, when compared to the neat PBAT blown film. As a result, PGA/PBAT blown films offer a variety of benefits, including superior ductility, toughness, and a strong gas barrier property. The potential of these films to degrade makes them a viable contender for replacing classical nondegradable packing films.

Avantium moves ahead on FDCA plant

Avantium is going ahead with plans to build a furandicarboxylic acid (FDCA) plant in Delfzijl, the Netherlands, after securing $100 million in financing for the facility. FDCA is reacted with ethylene glycol to make polyethylene furanoate, a polyester with strong barrier properties. Avantium will make FDCA from high-fructose syrup and is lining up customers that will use the resulting polymer. Avantium may have competition from the recently launched US start-up ReSource Chemical, which plans to make FDCA from nonfood biomass and carbon dioxide.

Characterization and film-forming properties of acid soluble collagens from different by-products of loach (Misgurnus anguillicaudatus)

In this study, acid soluble collagens (ASCs) from different by-products of loach including skin, head, fins and bone were isolated, characterized and compared. As a result, the highest yield (on wet weight basis) was obtained for ASC from skin (ASC-S, 9.73%) compared with those from fins (ASC-F, 2.01%), head (ASC-H, 1.12%) and bone (ASC-B, 0.84%). By SDS-PAGE, these collagens were classified as type I collagens with slight difference of molecular weight. Glycine was the major amino acid in all ASCs with relatively high contents of alanine, hydroxyproline and proline. Fourier transform infrared spectroscopy indicated that triple helical structures of all ASCs were well preserved and scanning electron microscope exhibited fibrillary structure of ASC-B while sheet structure in others. Thermal stability of ASCs was determined by differential scanning calorimetry, rheometer and thermogravimetric (TG), respectively. It was concluded that all ASCs had different maximum transition (Tmax), denaturation (Td) and onset decomposition (To) temperatures. Besides, film-forming properties of ASCs from loach were also evaluated with ASC-F film showing strong tensile strength, best extensibility and barrier property compared with others, which suggested that ASCs from different by-products of loach had tremendous potential for applications in food packaging and coating in future.

Nickel-zinc tungstate nanocomposites deposited on copper surface for corrosion protection in chloride solution

Several methods such as drop-casting, electrophoretic and chemical vapour depositions have shown the successful deposition of nanomaterials such as graphene oxide, cerium oxide, etc. on metals for various applications such as energy storage, and corrosion protection due to their large surface area and barrier formation. However, these films despite their strong barrier property have been less effective in the area of corrosion protection due to porosity and poor adherence. Here we describe an environmentally benign nickel-zinc tungstate (NiWO4-ZnWO4) nanocomposite with great adhesion and reduced porosity due to improved adsorption sites and film ordering inspired by deoxyribonucleic acid (DNA). The synthesis of the newly designed mixed-metal oxide was done via a simple wet-chemical process in the presence of DNA and in-absence of DNA. Electrochemical analyses confirmed improved corrosion protection of Cu by approximately two orders of magnitude by using nickel-zinc tungstate with DNA compared to only the sample without DNA and the blank system (without any inhibitor).

Highly durable organic photodetector for complementary metal oxide semiconductor image sensors

Utilizing organic electronics compatible with conventional semiconductor fabrication processes is extremely difficult because of their low chemical resistivity and poor environmental durability. To preserve the intrinsic functionality of organic materials, only a few fabrication processes can be used. Moreover, it is essential to achieve process expandability and silicon-process compatibility to develop high-resolution electronics suitable for mass production. Therefore, we developed wet-process-compatible organic photodetectors by replacing the conventional shadow-mask process with photolithography. This suppresses particle deposition during the serial fabrication processes, providing high operational stability. The fabricated green organic photodiodes exhibit a low dark current (1.0 × 10−11 A/cm2) with high photon–electron conversion efficiency (EQE = 65%). The charge collection and charge separation efficiencies are stable (ηcc = 84.6% and ηcs = 97.7%, respectively). Moreover, the organic semiconductors are compatible with conventional wet- and dry-etching processes owing to thin-film encapsulation layers. Finally, the novel organic image sensor can withstand 500 h under 85 °C/85% relative humidity and 1000 thermal cycles (−55–125 °C). Because of its robustness and strong barrier properties, the novel process architecture reported herein can be extended to any organic electronic devices, including widely commercialized organic light-emitting diodes and organic photovoltaic devices.

A pulmonary mucus surrogate for investigating antibiotic permeation and activity against Pseudomonas aeruginosa biofilms.

Pulmonary infections associated with Pseudomonas aeruginosa can be life-threatening for patients suffering from chronic lung diseases such as cystic fibrosis. In this scenario, the formation of biofilms embedded in a mucus layer can limit the permeation and the activity of anti-infectives. Native human pulmonary mucus can be isolated from endotracheal tubes, but this source is limited for large-scale testing. This study, therefore, aimed to evaluate a modified artificial sputum medium (ASMmod) with mucus-like viscoelastic properties as a surrogate for testing anti-infectives against P. aeruginosa biofilms. Bacterial growth in conventional broth cultures was compared with that in ASMmod, and PAO1-GFP biofilms were imaged by confocal microscopy. Transport kinetics of three antibiotics, tobramycin, colistin, and ciprofloxacin, through native mucus and ASMmod were studied, and their activity against PAO1 biofilms grown in different media was assessed by determination of metabolic activity and cfu. PAO1(-GFP) cultured in human pulmonary mucus or ASMmod showed similarities in bacterial growth and biofilm morphology. A limited permeation of antibiotics through ASMmod was observed, indicating its strong barrier properties, which are comparable to those of native human mucus. Reduced susceptibility of PAO1 biofilms was observed in ASMmod compared with LB medium for tobramycin and colistin, but less for ciprofloxacin. These findings underline the importance of mucus as a biological barrier to antibiotics. ASMmod appears to be a valuable surrogate for studying mucus permeation of anti-infectives and their efficacy against PAO1 biofilms.

Influencing factors and drug application of iontophoresis in transdermal drug delivery: an overview of recent progress.

Transdermal drug delivery is limited by the stratum corneum of skin, which blocks most molecules, and thus, only few molecules with specific physicochemical properties (molecular weight <500Da, adequate lipophilicity, and low melting point) are able to penetrate the skin. Recently, various technologies have been developed to overcome the strong barrier properties of stratum corneum. Iontophoresis technology, which uses a small current to improve drug permeation through skin, is one of the effective ways to circumvent the stratum corneum. This approach not only provides a more efficient, noninvasive, and patient-friendly method of drug delivery but also widens the scope of drugs for transdermal delivery. In this review, the mechanisms underlying iontophoresis and affecting factors are outlined. The focus will be on the latest advancements in iontophoretic transdermal drug delivery and application of iontophoresis with other enhancing technologies. The challenges of this technology for drug administration have also been highlighted, and some iontophoretic systems approved for clinical use are described.

Effect of supercritical incorporation of cinnamaldehyde on physical-chemical properties, disintegration and toxicity studies of PLA/lignin nanocomposites

Poly (lactic acid)/lignin nanocomposites (PLA/Lig-Np) containing cinnamaldehyde (Ci) were obtained by a combination of melt extrusion and supercritical impregnation process. In this work, Ci impregnation tests were carried out in a high-pressure cell at 40 °C for 3 h using 12 MPa and 1 MPa min−1 of depressurization rate, obtaining impregnation yields ranging from 5.7 to 10.8% w/w. Thermal, mechanical and colorimetric properties of the developed films were affected by the incorporation of lignin nanoparticles and the active compound, obtaining biodegradable plastic materials with a strong UV-light barrier property compared to PLA films. In addition, disintegrability tests under composting conditions confirmed the biodegradable character of nanocomposites developed. On day 23, a disintegration percentage greater than 90% was determined for all bionanocomposites. Finally, to establish the possible toxicity effect of the nanocomposites obtained, studies in vivo were performed in normal rats. Toxicity studies showed normal blood parameters after a single dose of nanocomposites. PLA/Ci/Lig-Np bionanocomposite films could be potentially applied to design biodegradable UV-light barrier materials for food packaging and biomedical applications.