Water Vapor Permeability Research Articles

Hollow fibers with encapsulated ionic liquid for gas dehydration

Membrane technology is a viable alternative for achieving energy savings and sustainability, particularly in dehydration applications. The selective removal of water vapor from gas mixtures by membranes enhances the process efficiency furthermore the industry increasingly prioritizes resource conservation and environmental impact, advancements in membrane technology are crucial for meeting these goals and driving progress toward a sustainable future. Our approach consists of the incorporation of a proline amino acid-based ionic liquid encapsulated in carbon capsules, dispersed in a Pebax®1657 matrix, and coated on polyetherimide hollow fibers. The filled capsules have high sorption capacity for both water vapor and carbon dioxide (CO2) contributing for successful exploration for air dehumidification, as well as flue gas, natural gas and biogas dehydration. The membranes had exceptional water vapor permeance, reaching values up to approximately 10,000 GPU while maintaining an H2O/N2 selectivity of around 124,000. CO2/N2 selectivity as high as 100 and promising results for CH4 purification were demonstrated. Long-term studies using alternative modules to prevent saturation of the encapsulated capsules with water vapor and effective regeneration have been proven.

Freestanding Hydrogen-Bonded Organic Framework Membrane for Efficient Wound Healing.

Hydrogen-bonded organic frameworks (HOFs) are emerging as multifunctional materials with exceptional biocompatibility, abundant active sites, and tunable porosity, which are highly beneficial for advanced wound care. However, a significant challenge involves transforming pristine HOFs powders into lightweight, ultrathin, freestanding membranes compatible with soft biological systems. Herein, the study successfully develops shape-adaptive HOF-based matrix membranes (HMMs) using a polymer-assisted liquid-air interface technique. The HMMs conform seamlessly to tissues of different sizes and shapes, effectively stopping bleeding, and provide high water-vapor permeability. Notably, both in vitro and in vivo studies with mice wound models demonstrated that these tissue-conformable HMMs significantly accelerate wound healing by modulating the inflammatory environment of the injured tissue and promoting rapid re-epithelialization. Furthermore, RNA-seq analysis and mechanistic studies revealed that HMMs effectively reduce inflammation and facilitate the tissue transition from the proliferative stage to the remodeling stage of skin development. This work not only opens up new avenues for advanced wound care materials but also establishes a foundation for hybridizing HOFs with polymers for a wide range of potential applications.

Fabrication of bamboo nanocellulose fibril-based food packaging with dual-antimicrobial property

The development of cellulose-based packaging films with excellent antimicrobial properties and biocompatibility has garnered significant attention. In this work, nanocellulose fibrils (NCFs) derived from from bamboo parenchyma cells were utilized to fabricate nanocomposite film with antimicrobial properties. This system exhibited distinct release behaviors for two antimicrobial agents, with the slow release of Ag nanoparticle (AgNP) in the initial stage contributed to delaying food spoilage, while the subsequent pH change in the microenvironment facilitated the release of essential oil of sour orange blossoms (SEO) for secondary antimicrobial activity. Additionally, the composite film demonstrated improved thermal stability and UV blocking capacity. Moreover, AgNP has been proven to enhance the mechanical properties, with the tensile strength of the novel composite film increasing by 34.85 % compared to control group. The water vapor permeability and oxygen permeability of the novel composite film were reduced, which could potentially reduce weight loss and slow down the rate of after-ripening. Following the acidification treatment, the films containing EO@MPN (essential oil encapsulated with metal-polyphenol network) component performed different antimicrobial patterns, indicating their pH-responsive antimicrobial capabilities, and they are effective against both Gram-positive and Gram-negative bacteria. After a 24-h exposure to a food simulant, the release amount of Ag was measured at 67.6 μg/dm2, within the acceptable limit, and the release profile of Ag was characterized. Cytotoxicity and Live/Dead staining tests confirmed that the novel composite film film had no significant toxicity, thus making it safe for application in food preservation. Furthermore, in a 15-day preservation experiment with mangoes, the novel composite film demonstrated the best performance, underscoring its potential as a sustainable antimicrobial packaging material.

Multifunctional electrospun nanofibrous film integrated with cinnamon essential oil emulsion stabilized by dealkali lignin for active packaging material

Cinnamon essential oil (CEO) has good antibacterial properties, but its volatility, hydrophobicity and bad odor limit its use in food preservation. In this study, a dealkali lignin (DAL) stabilized emulsion loaded with CEO was encapsulated into poly (vinyl alcohol) (PVA) and zein using an emulsion electrospinning technique. With the existence of DAL, the PVA/zein/DAL/CEO nanofibrous film (PVA/zein/DAL/CEO NF) exhibited good antioxidant properties. Moreover, higher antibacterial activity was achieved owing to the nanosized structure and enhanced stability compared to DAL/CEO emulsion and pure CEO. Scanning electron microscopy (SEM) revealed uniformly produced PVA/zein/DAL/CEO NF with an average diameter of 295 nm. The interactions among the nanofibrous film's components were confirmed using attenuated total internal reflectance fourier transform infrared spectroscopy (ATR-FTIR). The nanofibrous film demonstrated a low water vapor permeability (WVP) of 5.07 mm∙g/(m2∙h∙kPa), which was beneficial for reducing moisture transfer from the external environment to the interior of the packaging. Additionally, the PVA/zein/DAL/CEO NF also exhibited a marked enhancement in antioxidant activity, neutralizing 94.54 % of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. The nanofibrous film also demonstrated potent antibacterial effects, with inhibition zones measuring 19.47 mm for Escherichia coli (E. coli) and 30.37 mm for Staphylococcus aureus (S. aureus), respectively. This study provided a reference for preparing a multifunctional electrospun nanofibrous film integrated with CEO as an active packaging material.

Fluorinated B-72 hybrid silver doped modified nanoparticle as a coating for biological corrosion protection of ancient bricks

In this paper, a superhydrophobic organic-inorganic composite coating containing fluorinated B72 hybrid methyl-modified silica/(Ag doped TiO2) by hexamethyldisilazane (HMDS) (H-SiO2/Ag/TiO2) was prepared by means of a mild and an environmental friendly method. Transparency, adhesion, hardness tests and photocatalytic performance were measured to determine the content of Ag in TiO2 which the TiO2/AgNO3 ratio is 0.008 g/mL. The synthesized Ag/TiO2 nanoparticles were characterized by X-ray diffraction (XRD), Raman spectra and transmission electron microscope (TEM). The highest contact angle of coated ancient bricks was 148.66° and the color change value of ΔE⁎ before and after coating was <5 which is within an acceptable range. The physical properties such as apparent porosity and water vapor permeability (ΔMp) were studied. After weathering from acid, alkali, salt, water and ultraviolet radiation, the bricks coated by the composite coatings still have good hydrophobicity that the contact angle were >120° and minor degree of surface corrosion comparing with the ancient bricks. The inhibitory effect of the composite coating on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), and that on algae (Chlamydomonas and Dunaliella) were studied through bacteriostasis test and algae comparative experiments, respectively. Finally, the mechanism of the composite coating on antibacterial and anti-algae was studied. The results showed that the appearance of the ancient bricks was not changed after coating, and the anti-weathering, antibacterial and anti-algae properties of the ancient transformation were increased.

Green nanotechnology for the enhancement of antibacterial properties in lining leather: MgO-chitosan nanocomposite coating

Antimicrobial nanomaterials have received a lot of interest in recent years due to their potential to fight against microbial degradation, a common problem in leather products. In this study, a nanocomposite was synthesized with MgO nanoparticles prepared by Aloe vera leaf extract and chitosan (CS), as an innovative solution to this problem. Three nanocomposite samples (C1, C2, and C3) were formulated with varying ratios of MgO and chitosan and evaluated for antimicrobial efficacy against Escherichia coli and Bacillus subtilis. Leather treated with MgO/Chitosan nanocomposite (MgO/Chitosan-1:1) exhibited substantial inhibition zones of 13 mm and 12 mm against E. coli and B. subtilis, respectively. Characterization of MgO nanoparticles, chitosan, and MgO/CS nanocomposite was performed through FTIR, XRD, SEM, TGA, and cytotoxicity tests. The average particle size and crystallite size of MgO nanoparticles were found as 136 nm and 10.3 nm, respectively and a weight loss of 67 % for MgO/CS nanocomposite in thermogravimetric analysis. FTIR confirmed the successful incorporation of MgO nanoparticles into the chitosan matrix, evidenced by the presence of characteristic functional groups. Application of nanocomposite onto lining leather via spraying resulted in finished leather with improved color rub fastness, perspiration fastness, and thermal stability compared to untreated leather. In comparison to dry color rub fastness, wet color rub fastness was notably improved by the MgO/CS nanocomposite, with gray scale ratings ranging from 4/5 to 5. Perspiration fastness was marginally enhanced by the MgO/CS coating, with gray scale ratings ranging from 4/5 to 5 for both grain and flesh samples. Specifically, the coated leather exhibited a water vapor permeability (WVP) of 9.94 mg cm−2.hr−1 that was lower than both uncoated (12.37 mg cm−2.hr−1) and PVA-coated (11.22 mg cm−2.hr−1) leather. This study presents a promising solution to the challenge of microbial degradation in leather products and highlights the potential of natural sources for synthesizing functional nanocomposites with diverse applications in materials science and biotechnology.

ADHESIVE ABILITY OF GYPSUM-CONTAINING PLASTER COMPOSITIONS

The traditional material for the construction of buildings in the Northern Black Sea region is a cheap local stone ‒ limestone-shell rock. Most of the buildings in the central part of the city of Odesa, which are of historical and architectural value, are constructed of this material. With proper care and maintenance, these structures can perform their functions for hundreds of years, but as a result of shell rock moisture due to negligent operation and a number of other reasons, the supporting structures are damaged, followed by the collapse of the building. In many cases, the direct cause of the destruction of load-bearing walls is the damage or absence of the outer plaster layer. Repairing walls with cement compounds exacerbates the problem. The article discusses some aspects of the possible use of gypsum-based composite materials for repairing damaged walls of limestone-shell rock buildings. The requirements for the repair composition are formulated. The expediency of using gypsum as a binder for the repair plaster mixture for exterior repairs is substantiated. An ash-gypsum-cement composition was used to increase the water resistance of the plaster. Sufficient water resistance and vapor permeability of the proposed composition were confirmed. This paper presents the results of studying the adhesive strength of the contact of the developed composition with the surface of various materials. Methods and measuring equipment developed at the ODABA were used. The adhesion strength of the proposed mixture with the surface of shell rock is close to the standard strength. The use of the adhesive additive Ceresit CC 81 increases the adhesive strength of the joint of the proposed composition with shell rock by 1.5 ‒ 2 times. The optimal amount of the adhesive additive to be introduced will be determined by the results of a multifactorial experiment to study the effect of a complex of chemical additives of different functional purposes on the properties of the proposed repair composition.

Sodium alginate edible films incorporating cactus pear extract: antimicrobial, chemical, and mechanical properties

The potential benefits of biodegradable and functional food packaging materials have garnered increasing attention in recent years. Sodium alginate (SA), a commonly utilized polysaccharide, is particularly noteworthy for producing biodegradable films for food packaging. This study aimed to investigate SA-based edible films enriched with various proportions of cactus pear peel extract (CPPE). We assessed the films and extracts for total phenolic content, antimicrobial and antioxidant activities, as well as mechanical properties. Cactus pear peels powder (CPPP) exhibited higher contents of total polyphenols (1243.82 mg GAE/100 g), total flavonoids (18.92 mg QE/100 g), and betalains (2.28 mg/100 g). The main constituents detected were catechol, pyrogallol, catechin, and alpha-coumaric acid, with concentrations of 1013.82, 223.45, 148.21, and 101.02 ppm, respectively, contributing about 45.71%, 9.85%, 6.54%, and 4.46% of the total phenolic compounds. The thickness of the SA films increased from 0.220 mm to 0.265 mm. The tensile strength values ranged from 1.98 to 3.12, while the elongation at break values for SA-CPPE films decreased relative to the plain SA film. Moreover, the inclusion of CPPE improved the barrier characteristics (with water vapor permeability values for SA films with 1%, 2%, and 3% CPPE ranging from 0.72 × 10−5 g·h−1·m−1·Pa−1 to 1.68 × 10−5 g·h−1·m−1·Pa−1) and induced variations in flexibility and resistance. The plain SA film did not exhibit any inhibitory activity against bacteria and fungi. However, the inclusion of CPPE in alginate films showed favorable antibacterial properties, which improved progressively with increasing CPPE concentration. These findings highlight the potential of incorporating active alginate-based films in food preservation.

Sustainable materials for novel food packaging based on alginate, methylcellulose and glycerol films functionalized with gallic acid

In the last years, new sustainable materials have been explored as plastic replacement in food industry. With the objective of developing sustainable active materials for food packaging, polysaccharide-based films: alginate, methylcellulose and glycerol-based films (ALG-MC-GLY (65:30:5)) were formulated and functionalized with different concentration of gallic acid (0.1, 0.5 and 0.8 % w/v). The mechanical, physicochemical, optical and functional properties of the films were evaluated. The incorporation of gallic acid resulted in films less resistant to tensile stress and less elastic, exhibiting reduced water vapor permeability. The physico-mechanical characterization was corroborated by FTIR spectra, HRSEM imaging and BET analyses, which demonstrated the interactions between the polymeric chains and gallic acid through localized hydrogen bonding, leading to denser structures with increased brittleness at higher concentrations of gallic acid. Moreover, the films functionalized with gallic acid displayed enhanced antioxidant properties in a concentration-dependent manner. These findings suggest that the ALG-MC-GLY based films loaded with gallic acid hold significant promise as alternative active food packaging materials.

Antimicrobial gelatin-based films with cinnamaldehyde and ZnO nanoparticles for sustainable food packaging

Cinnamaldehyde (CIN), a harmless bioactive chemical, is used in bio-based packaging films for its antibacterial and antioxidant properties. However, high amounts can change food flavor and odor. Thus, ZnO nanoparticles (NPs) as a supplementary antimicrobial agent are added to gelatin film with CIN. The CIN/ZnO interactions are the main topic of this investigation. FTIR-Attenuated Total Reflection (ATR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were utilized to investigate CIN/ZnO@gelatin films. Transmission electron microscope (TEM) images revealed nanospheres morphology of ZnO NPs, with particle sizes ranging from 12 to 22 nm. ZnO NPs integration increased the overall activation energy of CIN/ZnO@gelatin by 11.94%. The incorporation of ZnO NPs into the CIN@gelatin film significantly reduced water vapour permeability (WVP) of the CIN/ZnO@gelatin film by 12.07% and the oxygen permeability (OP) by 86.86%. The water sorption isotherms of CIN/ZnO@gelatin were described using Guggenheim-Anderson-de Boer (GAB) model. The incorporation of ZnO NPs into the CIN@gelatin film reduced monolayer moisture content (M0) by 35.79% and significantly decreased the solubility of CIN/ZnO@gelatin by 15.15%. The inclusion of ZnO into CIN@gelatin film significantly decreased tensile strength of CIN/ZnO@gelatin by 13.32% and Young`s modulus by 18.33% and enhanced elongation at break by 11.27%. The incorporation of ZnO NPs into the CIN@gelatin film caused a significant decrease of antioxidant activity of CIN/ZnO@gelatin film by 9.09%. The most susceptible organisms to the CIN/ZnO@gelatin film included Candida albicans, Helicobacter pylori, and Micrococcus leutus. The inhibition zone produced by the CIN/ZnO@gelatin film versus Micrococcus leutus was 25.0 mm, which was comparable to the inhibition zone created by antibacterial gentamicin (23.33 mm) and cell viability assessment revealed that ZnO/CIN@gelatin (96.8 ± 0.1%) showed great performance as potent biocompatible active packaging material.

Biodegradable packaging paper derived from chitosan-based composite barrier coating for agricultural products preservation

Development of green packaging materials is essential to replace traditional plastics in fresh agricultural products preservation. Herein, a coated paper was designed by applying chitosan-based composite coating on paper substrate through a facile automatic coating method. The hydroxypropyl trimethyl ammonium chloride chitosan (HACC) was obtained by direct quaternization via the introduction of hydroxypropyl trimethyl ammonium chloride into the amino group of chitosan, then mixed with polyvinyl alcohol (PVA) to prepare the HACC/PVA coating. Accordingly, the key performance of coated paper were improved ascribed to the synergy effect of HACC/PVA coating and paper substrate. In particular, the minimum oxygen permeability of the coated paper could reach to 0.87 × 10−13 cm3·cm/cm2·s·Pa, and the optimum water vapor permeability and tensile strength of HACC/PVA coated paper was 0.75 × 10−12 g·cm/cm2·s·Pa and 6.88 kN/m, respectively. The coated paper used as packaging material not only reduced weight loss ratio of strawberry and greengrocery, but also exhibited lower chromatic aberration and better sensory evaluation, indicating a favorable effect on fruit and vegetable storage. Taken together, the designed eco-friendly coated paper has shown tremendous potential for green and biodegradable packaging material in agricultural products preservation.

Enhanced functional pectin films incorporated with olive fruit extracts prepared by deep eutectic solvents

The effect of olive extracts extracted with deep eutectic solvent (DES: choline chloride/glycerol, dl-malic acid/sucrose/glycerol, and citric acid/glycerol, respectively) on the structure, physical properties, and functional activities of pectin films, using DES both as a plasticizer and an extraction medium were explored. The findings revealed the integration of DES as a plasticizer was observed to increase film’s water vapor permeability and elongation at break, while concurrently diminishing its opacity. Furthermore, the incorporation of DES-olive extracts significantly enhanced the tensile strength, moisture barrier property, and opacity of the film, as well as improved its antioxidant and antibacterial activities. The structural analysis indicated the interaction among DES, olive extracts, and pectin facilitated the development of more ordered structures within the films, thereby improving the thermal stability of the pectin-based films. In conclusion, pectin active films using DES as a solvent and plasticizer have the potential to be used to improve antimicrobial and antioxidant packaging materials along with acceptable water resistance.

Methods for Fabrication of Self/Free Standing Nanocellulose (NC)-Nano Montmorillonite (N-MMT) Composite Films/Sheets — A Review

Plastic pollution looms large as a formidable foe to the environment. Enter cellulose nanofibers, the shining stars in the quest for innovative, eco-friendly paper-based packaging that is not just renewable, but also recyclable and biodegradable. These cellulose wonders boast impressively low oxygen permeability, but when it comes to water vapor, they fall short compared to traditional packaging plastics like LDPE. To tackle this challenge, researchers have been crafting composites by blending cellulose nanofibers with inorganic nanoparticles, such as Montmorillonite clay, which helps to curb water vapor permeability. However, this clever addition comes with a catch — it further complicates the already tricky drainage process during layer formation via vacuum filtration. This review delves into the complex world of nano cellulose-nano-MMT (Montmorillonite) composites, examining their preparation processes, unique characteristics, wide-ranging uses, and their significant contribution to promoting circular economy principles. By combining cellulose nanomaterials with MMT, a synergistic approach is taken to develop a new composite material with improved mechanical, thermal, and barrier properties. Various fabrication techniques are explored, including solution blending, in-situ polymerization, and electrospinning, allowing for customized design and optimization of the composite material. The review discusses how the nano cellulose-MMT composite demonstrates enhanced mechanical strength, thermal stability, and barrier properties, positioning it as a sustainable option compared to traditional materials. The review also showcases the diverse applications of these nano-composites in fields like packaging, biomedical devices, and environmental cleanup, emphasizing their alignment with circular economy principles. By examining the entire life cycle of these composites, from production to use and eventual disposal or recycling, the review underscores their role in supporting a circular economy. In light of the ongoing efforts by the scientific community and various industries to identify environmentally sustainable solutions, it is imperative to comprehend the synthesis, properties, and applications of nano cellulose-MMT composites. This understanding is essential for advancing sustainable processing for green material development.

Valorization of okara by-product for obtaining soluble dietary fibers and their use in biodegradable carboxymethyl cellulose-based film

In the face of mounting environmental concerns and the need for sustainable innovation, the use of agro-industrial wastes as raw materials offers a promising pathway. In this context, this study investigated the okara, a by-product of soy processing, as a novel source of soluble dietary fiber for the enrichment of carboxymethyl cellulose (CMC) biodegradable films based on environmental benefits of waste reduction with the creation of renewable packaging alternatives. Okara soluble dietary fiber (OSDF)-enriched CMC film was compared with films made from traditional and innovative soluble dietary fibers, such as pectin, inulin, and β-glucan. OSDF was obtained through acid hydrolysis at 121 °C, achieving a yield of 5.31 % relative to its initial dry weight. All the produced films exhibited a maximum crystallinity of 5 %, as revealed by X-ray diffraction (XRD), indicative of their largely amorphous structure, while scanning electron microscopy (SEM) ensured their uniformity and flawlessness. The CMC film enriched with okara soluble dietary fiber exhibited key properties, such as thickness, water vapor permeability, and thermal stability, comparable to other soluble fibers studied. These characteristics are essential for effective packaging applications. A notable distinction of the OSDF-enriched film was its capacity to block UV light, offering protection for light-sensitive items. The solubility tests showed that okara and β-glucan contributed to films with a higher solubility percentage. Mechanical testing underscored the influence of fiber on tensile strength, with the film enriched with β-glucan outperforming others at 27.5 MPa. All films showed rapid biodegradation within one week, emphasizing their eco-friendliness and the study alignment with sustainable development objectives in packaging.

Design and Characterization of an Antimicrobial Biocomposite for Wound Dressings.

Skin wounds, due to their high vulnerability to infections, represent a significant public health issue. These wounds are not only disabling but also entail costly treatments and slow recovery. Consequently, it is crucial to implement new treatments based on bioactive and natural antimicrobial compounds utilizing fibers, polymers, hydrocolloids, and hydrogels to control potential infections and promote wound healing. This study aimed to develop a biocomposite with antimicrobial activity for the treatment of skin wounds, using sodium alginate, bamboo fiber, and a natural antimicrobial as ingredients. The physico-mechanical properties (Young's modulus, tensile strength, elongation at break, moisture absorption, and water vapor permeability) and antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Staphylococcus hominis were determined. The results demonstrated that the designed biocomposite possesses adequate physico-mechanical properties, such as flexibility, strength, and water absorption capacity, in addition to exhibiting antibacterial activity, making it suitable to be used as a dressing in wound treatment.

Enhancing eco-friendly coatings: Aqueous olive leaves extract fortifies macroalgae-based packaging materials

This study incorporated bioactive compounds extracted from olive leaves (Olea europaea L.) into biodegradable films designed for preserving perishable food items like fruits and vegetables. Olive leaves, sourced from Lesvos island in Greece, yielded three aqueous extracts - OL1, OL2, and OL3 – representing different cultivated species. The antioxidant potential and phenolic compound profile of these extracts were analyzed. Subsequently, these extracts were integrated into 2% sodium alginate solutions, and the resulting mixtures were cast into 90 mm Petri dishes to form solid biofilms. Our findings reveal that the olive leaf extracts offer protection against UV–VIS radiation. Particularly, OL1 showcased the highest antioxidant capacity among the extracts examined. For the solid biofilms, various physical characteristics such as weight, diameter, density, and thickness were measured, alongside evaluating humidity, solubility in water, and water vapor permeability. The rheological properties of these solutions, influenced by temperature and extract addition, affect the viscosity, flow behavior, and gelation capacity, crucial for coating applications. Our research not only explores the impact of olive leaf extracts and glycerol as a plasticizer on biofilm solutions but also sheds light on increased opacity, reduced light absorption, and altered rheological properties. This endeavor aligns with the ongoing pursuit of sustainable packaging alternatives, emphasizing the crucial role of bioactive compounds in enhancing the functionality and eco-friendliness of biodegradable films.

Spider web-reinforced chitosan/starch biopolymer for active biodegradable food packaging

In this study, starch (ST), chitosan (CH), spider silk (SW), and their hybrid composite bioplastics were fabricated and examined for physicochemical and mechanical properties. The essential oils (EOs) of Rosmarinus officinalis were encapsulated to enhance their biological application. The prepared composite films were characterized using various spectroscopic techniques such as XRD, SEM, GCMS–, UV–VIS, TGA, and FTIR spectroscopy. The antimicrobial activity of the prepared film was tested against S. aureus bacterial and C. albican fungal strains which showed a greater zone of inhibition for the composite film encapsulated with EOs. The biodegradability of the synthesized film was evaluated for 60 days in soil under laboratory conditions. The composite film containing spider web and essential oil significantly improved mechanical properties. The physicochemical results, such as moisture, solubility, swelling, transmittance, opacity, and water vapor permeability, of the prepared bioplastic were comparable with those of the control plastic. The EO-based film had greater antioxidant activity against DPPH, hydrogen peroxide, and phosphomolybdenum assays, with an inhibition range of 60–70 %. The addition of spider web and essential oil to the chitosan/ starch film significantly increased the shelf life of injera and tomatoes for 7 and 10 days, respectively for the EO-based film. The biodegradability of the synthesized film has shown a great reduction in the weight and growth of microorganisms. In general, the CH/ST/SW and CH/ST/SW/EOs composite films have greater mechanical, biological, physicochemical, and potential improvement of food shelf life applied as either coating or packaging material.

Controlled localization of graphene oxide to improve barrier, biodegradation and mechanical properties of PBAT/EVOH

AbstractIncorporating graphene oxide (GO) with controlled localization into poly(butylene adipate‐co‐terephthalate) (PBAT) blends with poly(ethylene vinyl alcohol) (EVOH) aimed to improve barrier properties, biodegradability, and mechanical strength of PBAT. The PBAT/EVOH/GO nanocomposites containing 0 to 1 wt% of GO were prepared by a reactive mixing process in internal mixer. Microscopic images confirmed that the GO nanoplatelets are mainly localized in PBAT phase and then at the interface, contrary to the thermodynamic affinity of GO toward EVOH. The reactive nature of PBAT/EVOH/GO nanocomposites was confirmed via time‐sweep rheological studies where specific changes were observed in melt viscosity over time. The results of microscopic studies, rheometry, tensile test, and dynamic mechanical thermal analysis (DMTA) confirmed that localizing GO at the interface establishes strong interactions between PBAT and EVOH. By the addition of 0.75 wt% GO, tensile and yield strength were improved by 19% and 45%, respectively. Increasing GO significantly increased the hydrolysis degradation rate of the nanocomposites. Furthermore, the addition of GO considerably decreased the oxygen and water vapor permeability of the blends by up to 40% at 1 wt% GO.

Effect of Different Ratios of Polyvinyl Alcohol‐Gum Odina for the Preparation and Characterization of Biodegradable Composite Films

ABSTRACTThis research investigates the production of biodegradable films using a combination of gum odina (GO) and polyvinyl alcohol (PVA) with varied ratio. The study focuses on the chemical, physical, and mechanical properties of PVA‐GO composite films, emphasizing how versatile and biodegradable they may be for a range of packaging applications. Solvent‐cast PVA‐GO films with different ratios are subjected to a methodical analytical process to determine several parameters like mechanical qualities, thermal stability, biodegradability in soil, contact angle, transparency, water vapor permeability, moisture content, thickness, density, water solubility, microstructure, and FTIR analysis. The outcomes demonstrate that GO improves UV barrier qualities and water vapor permeability. Additionally, the films showed notable biodegradability, acceptable thermal stability, and mechanical qualities. In short, PVA‐GO films can provide an eco‐friendly packing substitute with adaptable qualities fit for a range of uses. Therefore, this research may further contribute promising information in the field of biodegradable packaging materials in the future.

Stretchable Composite Films Are Prepared by Using Cellulose Pulp with Differential Substitution of Carboxymethyl Cellulose and Thymol with an Infrared Heating Process for Packaging Application.

Herein, cellulose pulp (CP), carboxymethyl cellulose (CMC), and thymol-based eco-friendly, transparent, and flexible composite films are prepared. These materials dissolved well in an environment-friendly process in N-methyl morpholine N-oxide (NMMO) ionic liquids using infrared heating. Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses are used to study the structure, microstructure, and morphology of the composite films. The thermal properties of the CP/CMC/thymol composites are thoroughly studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal stability of the composites (T 5%-57.8-91.2 °C and T 10%-216.6-284.1 °C) significantly improves following the CMC addition. In each case, all the composite film exhibits unique T g (140.5-143.1 °C) values, as confirmed by DSC. The tensile strength of the cellulose pulp is 66.5 MPa, increasing to 78.4 MPa for the CP/CMC-1:0.5 composites and steadily increasing to 93.8 MPa with increasing CMC content. Similarly, CMC increases the EB of cellulose pulp from 9.3 to 7.4%. The water vapor permeability and swelling ratio values of the CP/CMC/thymol composites are in the range of 1.9-2.11 × 10-9 g/(m2·Pa·s) and 52.5-50.8° respectively. The CP, CMC, and thymol-based composite do not exhibit cytotoxicity to the aneuploid immortal keratinocyte cell line and demonstrate excellent antioxidant properties, for promising packaging and biomedical applications.