Search Results (520)

Pectin films are promising renewable materials for biodegradable coatings; however, their high hydrophilicity and limited resistance to ultraviolet (UV) radiation restrict practical applications. This work investigated the influence of kraft lignin (0–5 wt%) on the structure–property relationships of grape-derived pectin films before and after accelerated UV exposure. Structural organization (XRD and FTIR), photostability (CIELAB colorimetry and CIE chromaticity), wettability, water-vapor absorption, surface morphology, soil-burial disintegration, and integrated multifunctional performance were evaluated. Lignin improved resistance to UV-induced structural changes, reducing the relative loss of apparent crystallinity from 52.76% for neat pectin to less than 7% for films containing at least 0.1 wt% lignin, while substantially decreasing UV-induced color changes. Increasing lignin content also reduced surface wettability, water-vapor uptake, and soil-burial mass loss; nevertheless, all formulations exhibited more than 50% mass loss after 120 h of soil burial. Exploratory CRITIC–TOPSIS analysis identified Pec/Lig₁ as the highest-performing formulation, whereas Pec/Lig_0.1 provided the most compositionally efficient balance among photostability, moisture resistance, structural stability, soil-burial disintegration, and lignin consumption. These findings demonstrate that lignin governs the trade-offs among structural stability, photostability, moisture resistance, soil-burial disintegration, and additive consumption, establishing composition–structure–property–durability relationships that provide practical design guidance for candidate functional coatings for cellulose- and paper-based substrates. Full article

To overcome the limitations of conventional biopolymer films and reduce reliance on petroleum-based plastics, a nacre-inspired film was developed via 3D printing. During printing process, shear-induced alignment of mica flakes was achieved within a sodium alginate/xanthan gum matrix. Additionally, zinc oxide nanoparticles (ZnO NPs) were incorporated to achieve a synergistic reinforcement effect. Structural analysis revealed that the mica flakes within the film exhibited an oriented distribution, with ZnO NPs uniformly embedded in the interlayer voids, and hydrogen bonding assisted in forming a dense network of the components. Performance testing showed that the tensile strength rose from 13.8 MPa to 62.9 MPa. Improvements in water resistance and thermal stability were also observed. Furthermore, the material exhibited outstanding comprehensive protective properties, including a low water vapor permeability value of 7.587 × 10⁻¹¹ g·m/m²·Pa·s, an ultraviolet blocking rate of 99.37% at a wavelength of 280 nm, and the ability to completely inhibit target bacterial strains, while also possessing good biodegradability and recyclability. Shelf-life tests indicated that the film fabricated in this work could notably prolong the shelf life of strawberries. Biocompatibility test results indicated that the film was safe and non-toxic, and showed no significant cytotoxicity. Full article

This research study focused on the use of technologies such as high-pressure processing (400 MPa for 15 min, HPP) and enzymatic hydrolysis (with cellulase) to process eucalyptus pulp, subsequently the pulp submitted to carboxymethylation to produce cellulose films and investigate their properties. The results revealed that the combination of HPP and cellulase resulted in the production of partially transparent and smoother films. As for mechanical properties, this combination resulted in a 2.7-fold increase in the tensile strength (TS) value, a 35.5-fold increase in the elongation at break (EAB) value, and a 1.4-fold increase in the moisture content of the films. The crystallinity index (CrI) was also increased by HPP and enzymes, resulting in a 6.6-fold increase, compared to the control film. On the other hand, the combined use of HPP and enzymatic hydrolysis resulted in similar contact angle (CA) values on both sides of the films, but in the bottom side, when compared to the control film, a 2.1-fold decrease was observed. Furthermore, the water vapor permeability (WVP) of the films increased 1.8-fold. Finally, the thermal resistance of the films was slightly reduced when either HPP, enzymatic or both treatments were used on the cellulose pulp. In general, this work showed a new potential way to produce cellulose films with novel and potentially tailor-made properties. Full article

This study aimed to systematically evaluate the effects of the Zein/poly(vinylidene fluoride) (PVDF) blend ratio on the formation, structure, and performance of electrospun nanofiber membranes and to further assess the feasibility of incorporating bromothymol blue (BTB) into the optimized matrix as a pH-responsive functional component for intelligent food-packaging applications. Increasing PVDF content reduced the conductivity but increased the viscosity of the spinning solutions, and all formulations exhibited shear-thinning behavior. Pure Zein failed to form continuous fibers, whereas PVDF incorporation promoted uniform fibrous networks, with average fiber diameters increasing from 113.02 ± 27.06 nm to 530.68 ± 113.33 nm. FTIR and TGA/DTG analyses confirmed the coexistence of Zein and PVDF and the improved thermal stability associated with increasing PVDF content. Surface hydrophobicity and water resistance increased with PVDF content, whereas water vapor permeability (WVP) and water solubility (WS) increased with the Zein proportion. Considering spinnability, morphology, mechanical behavior, barrier performance, and water stability, the Zein/PVDF = 5:5 formulation provided a comparatively balanced performance and was selected as the functional carrier matrix. Incorporation of BTB into this matrix produced a distinct pH-responsive color change, and the color difference (ΔE) showed a strong correlation with shrimp pH during storage (R² = 0.997), demonstrating the feasibility of the optimized membrane as a freshness-responsive functional carrier. Full article

La₂Si₂O₇ is a candidate environmental barrier coating (EBC) material for silicon carbide ceramic matrix composites in next-generation gas turbine engines, yet its degradation behavior under the simultaneous attack of molten CMAS and water vapor remains insufficiently understood. This study systematically examines atmospheric plasma-sprayed La₂Si₂O₇ coatings exposed to four environments (air, CMAS alone, H₂O/O₂ alone, and combined CMAS + H₂O/O₂) at 1400 °C for 8 h. Under dry air, the coating recrystallizes to La₂Si₂O₇ with negligible corrosion. CMAS attack triggers a dissolution–reprecipitation mechanism forming needle-like CaLa₄(SiO₄)₃O apatite within a denser reaction zone, which partially impedes further infiltration. Water vapor accelerated the growth of the thermally grown oxide at the bond coat interface. The combined CMAS + H₂O/O₂ environment produced a pronounced synergistic acceleration: water vapor reduced CMAS melt viscosity, enabling deeper CMAS penetration, while concurrent silica volatilization disrupted the protective apatite barrier, generating extensive porosity and through-coating cracking. These findings reveal that the inherent CMAS resistance of La₂Si₂O₇ via apatite formation is critically compromised by simultaneous water vapor, highlighting a key challenge for its application in realistic engine environments. Full article

Waterborne poly(vinyl alcohol) (PVA) adhesives are widely used in iodine-based polarizers, owing to their excellent transparency and interfacial adhesion. However, the intrinsic hydrophilicity of PVA compromises the long-term durability of polarizers under humid conditions. Herein, graphene derivatives with tunable oxygen contents and graphitization degrees, including graphene oxide (GO), partially reduced graphene oxide (rGO), and graphene nanosheets (GNs), were incorporated into a PVA/PEI adhesive system to investigate the oxygen-content-dependent interfacial interactions and moisture-barrier mechanisms. Structural analyses reveal that oxygen-rich GO enhances interfacial hydrogen bonding and polymer–graphene interactions, whereas highly graphitized GN primarily functions through its intrinsic lamellar barrier effect by increasing diffusion tortuosity and reducing water affinity. The rGO exhibits a compromise between interfacial interactions and barrier effects due to its moderate oxygen content and preserved graphene structure. Among them, the GN-modified adhesive demonstrates the most favorable overall performances, achieving a 14.71% reduction in the water vapor transmission rate (WVTR) of the assembled polarizer, enhanced moisture resistance, and improved antistatic capability while maintaining acceptable optical transparency. Furthermore, practical polarizer evaluations confirm that GN effectively suppresses moisture penetration, with only slight bubbling observed after 8 days of water immersion and no delamination or polarization degradation during a 40-day immersion test. These findings provide insights into the relationship between graphene oxygen content, interfacial interactions, and moisture-barrier behavior, offering an effective strategy for designing durable multifunctional waterborne adhesives for advanced optoelectronic polarizer applications. Full article

Starch-based bioplastics are renewable and biodegradable, but their wider use is constrained by moisture sorption, humidity-dependent aging, insufficient tensile performance, and weak water- and oxygen barrier stability. This review critically synthesizes the peer-reviewed literature from 2020 to 2026 on enzymatically engineered starch for film, packaging, and thermoplastic applications using an architecture–property framework that links enzyme specificity, chain-length distribution, crystallinity, processing route, and material response. Controlled α-1,4 hydrolysis mainly improves processability by lowering molecular weight, viscosity, and gelatinization resistance. However, excessive hydrolysis can increase water uptake, solubility, and loss of cohesive strength. Debranching by pullulanase or isoamylase increases amylose-like linear chains and can promote B-type crystallinity or V-type starch–lipid complexes, with reported gains in tensile strength, contact angle, and water vapor barrier when the chain lengths and recrystallization conditions are controlled. Branching enzymes and transglycosylases increase branch density or redistribute glucan chains, suppressing retrogradation and improving flexibility, water retention, and aging resistance, but often with trade-offs in strength, crystallinity, and barrier performance. Lipase- and laccase-catalyzed functionalization expands starch functionality by increasing hydrophobicity, compatibility with hydrophobic phases, antioxidant activity, and active-packaging potential. The evidence indicates that enzymatic modification should not be generalized as uniformly improving starch bioplastics; performance gains are conditional on the starch source, amylose content, enzyme dosage, reaction severity, plasticizer composition, processing method, film conditioning, and storage humidity. Industrial implementation remains limited by enzyme cost and reuse, high-solids mass transfer, reaction time, enzyme stability under heat and shear, and reproducibility across botanical sources. Overall, enzymatic molecular editing is most promising when mechanistic architecture control is coupled with standardized structure–property reporting and scalable processing, such as immobilized-enzyme reactors, high-solids systems, and reactive extrusion. Full article

The enduring popularity of denim in the global apparel market is attributed to its outstanding durability, resistance to repeated laundering, and versatility in adapting to changing fashion trends, making it one of the most widely used fabrics in the textile industry. The incorporation of elastane into denim fabrics enhances their elasticity and improves the wearer’s freedom of movement. In addition to stretch performance, optimizing the thermal comfort of stretch denim fabrics has become an important aspect of advanced textile material development. Unlike previous studies, this research provides a comprehensive evaluation of the combined effects of elastane content and repeated home laundering on the structural and thermal comfort properties of stretch denim fabrics. Five denim fabrics containing different elastane ratios were produced, and their dimensional shrinkage, fabric weight, thickness, fractional cover, thermal resistance, air permeability, and relative water vapor permeability were determined before and after five laundering cycles. Statistical analyses were performed to evaluate the effects of elastane content and laundering. The results demonstrated that laundering induced significant structural changes, including increased dimensional shrinkage, fabric weight, thickness, and fractional cover, which consequently altered the comfort performance of the fabrics. Thermal resistance and relative water vapor permeability increased after laundering, whereas air permeability decreased significantly (p < 0.05). Correlation analysis further revealed strong statistically significant relationships between the structural characteristics and the measured comfort properties, confirming that both elastane content and laundering are key factors governing the thermal comfort performance of stretch denim fabrics. These findings provide valuable guidance for optimizing the design and laundering performance of stretch denim fabrics with improved thermal comfort and may also contribute to future studies involving functional and technical applications of denim materials. Full article

Accurate estimation of evapotranspiration (ET) and transpiration (T) is crucial in enhancing irrigation schedules in agricultural ecosystems. A simplified canopy resistance ($r_s^c$) algorithm grounded in the Ball-Berry model was integrated into Penman–Monteith (PM)-based models and assessed in a humid-region kiwifruit orchard. The Shuttleworth–Wallace (SW) and Clumping (CL) models agreed well with eddy covariance ET (ET_EC) throughout the growth season (R² = 0.79 and 0.89, RRMSE = 0.73–0.75 and 0.22, at the sub-daily and daily scales), outperforming the Two-Patch (TP) and topography- and vegetation-based surface energy partitioning (TVET) models. SW and CL also best reproduced sap-flow-based T (T_SF) (R² = 0.72 and 0.71–0.72, RRMSE = 0.85–0.87 and 0.38–0.39), primarily due to their higher accuracy during the mid stage. In this ecosystem, canopy interception evaporation had only a limited influence on the simulation performance of the SW and CL models. ET and T were most sensitive to changes in $r_s^c$ and related environmental factors, including gross primary productivity (GPP), the empirical parameter (a₁), and soil water content (θ). The sensitivity of T to θ was higher during the early stage but lower during the mid and late stages due to seasonal drought. ET was more sensitive to θ than T, due to its direct effect on soil surface resistance ($r_s^s$). T simulated by TP, TVET, and CL models showed greater sensitivity to leaf area index (LAI) than SW, while contrasting T and soil evaporation (E) responses to LAI caused ET to remain relatively insensitive. Both ET and T were highly sensitive to net radiation (R_n), air temperature (T_a), and vapor pressure deficit (VPD), all of which directly affect the energy balance. Overall, integrating the simplified canopy resistance algorithm with PM-based models improves ET and T estimation in humid-region orchards, supporting more efficient water management. Full article

This study examines how yarn microstructure influences isothermal water-vapor transport and the associated evaporative heat loss under ISO 11092 skin-model conditions. Sweating guarded hotplate experiments were performed on PET yarn-array specimens to measure evaporative heat flux and moisture resistance. A fiber-level two-dimensional finite element model was then developed to reproduce the same boundary conditions and simulate transport through a PET fiber/air matrix. Using a full-factorial design, denier per filament, the number of filaments, and packing factor were varied independently, with multiple random filament arrangements used for each parameter combination to account for microstructural variability. The model reproduced the main experimental trends and gave predictions consistent with measured heat flux and moisture resistance for representative yarn configurations. Over the investigated design space, packing factor had the strongest influence: higher packing reduced heat and moisture flux and increased moisture resistance. Denier per filament and the number of filaments showed smaller but systematic effects, mainly through changes in pore connectivity and tortuosity. Statistical analysis indicated that main effects accounted for most response variation, while interaction effects were limited within the studied ranges. Flow-field results further showed a shift from internal flow penetration at low packing to bypass-dominated transport at high packing. These findings provide a validated framework for linking yarn-level structural parameters with heat–moisture transport performance in fibrous assemblies. Full article

Constructing catalytic materials with specific morphologies is an effective approach to boosting and optimizing their catalytic performances. Herein, SnO₂ supports with diverse morphologies of nanosphere, nanosheet and nanorod were separately synthesized for the fabrication of supported Ru catalysts. Catalytic evaluation results for vinyl chloride (VC) oxidation reveal that the nanosphere-shaped catalyst (Ru/SnO₂-Sp) exhibits the optimum catalytic activity (achieving 90% of VC conversion at 268 °C), exceptional long-term catalytic durability, and cyclic stability comparable to nanosheet-shaped and nanorod-shaped catalysts (Ru/SnO₂-Sh and Ru/SnO₂-Rd). Additionally, Ru/SnO₂-Sp presents promising applicability with regard to its impressive resistance behavior towards carbon dioxide and water vapor interference. Characterization results clearly demonstrate the close structure–activity relationship, primarily depending on the physicochemical parameters of specific surface area, redox capacity, surface oxygen species and valence state distribution of Ru. In situ infrared spectroscopy clarifies the key catalytic pathways of VC oxidation over Ru/SnO₂-Sp, evidencing that the enol species from C-Cl bond cleavage and initial activation of VC molecules and the carboxylic acid species resulting from the subsequent oxidation of enol are both recognized as the crucial organic intermediates. Full article

The poor moisture resistance of gypsum remains one of the main factors limiting its wider application in construction. This study investigates a novel approach to improving the moisture resistance of gypsum through the addition of soluble salts capable of reacting with dissolved calcium sulfate to form insoluble products within the gypsum matrix. The formation of insoluble reaction products was considered as one of the possible mechanisms contributing to this effect. Three salts were examined—trisodium phosphate dodecahydrate (TSP), potassium sodium tartrate tetrahydrate (PS), and sodium oxalate (SO)—each added at 2 wt.% of gypsum mass. The influence of the salts on phase composition, microstructure, setting behavior, density, porosity, mechanical properties, and water-vapor transport was evaluated. The reference gypsum exhibited compressive strengths of 5.18 MPa and 0.79 MPa and flexural strengths of 3.01 MPa and 0.57 MPa after storage in laboratory conditions and water, respectively. The results showed that salt chemistry strongly affected gypsum performance. TSP significantly altered crystal morphology, accelerated the initial setting time from 16.0 min to approximately 4.0 min, and delayed the final setting to the third day after mixing. Consequently, TSP exhibited the poorest mechanical performance, with compressive strengths of 2.77 MPa and 0.09 MPa and flexural strengths of 2.03 MPa and 0.27 MPa in dry and wet conditions, respectively. In contrast, the organic salts PS and SO preserved a gypsum crystal network similar to that of the reference material. PS achieved compressive strengths of 4.89 MPa and 0.79 MPa and flexural strengths of 2.84 MPa and 0.67 MPa, while SO reached 4.43 MPa and 0.34 MPa in compression and 2.59 MPa and 0.55 MPa in flexure. Moreover, PS and SO improved the flexural softening coefficient by 24% and 11%, respectively, whereas TSP reduced it by approximately 30%. Total porosity ranged from 53 to 61% for specimens stored in laboratory conditions and decreased to 35–39% after water storage. Water-vapor diffusion resistance was affected only marginally, and the vapor-open character typical of gypsum materials was preserved. Among the investigated admixtures, potassium sodium tartrate exhibited the most promising overall performance, maintaining compressive strength after water exposure at the same level as the reference gypsum while improving moisture resistance. The results indicate that the selected organic salts represent a promising route for improving the moisture resistance of gypsum-based materials. However, the present results suggest that the observed improvement cannot be attributed solely to the formation of insoluble reaction products, and further research is required to clarify the relative contribution of the underlying mechanisms. Full article

The food packaging sector widely relies on polymeric materials, and as sustainability concerns grow, commodity polymers need to be replaced with innovative and more sustainable materials. Thermoplastic polyurethane (TPU) is a versatile elastomeric polymer characterized by flexibility, strength, chemical and abrasion resistance, and biocompatibility. However, it presents some limitations, notably in terms of functional properties (i.e., barrier properties). The use of nano-sized renewable fillers, such as cellulose nanocrystals (CNCs), may improve these properties, extending the applicability range of TPU. In this work, bio-based TPU nanocomposites were obtained by adding commercial silane-modified cellulose nanocrystals (Si−O−CNC) at different contents (1–5 wt.%). The nanocomposites were produced via melt mixing followed by compression molding and were characterized in terms of chemical (FTIR), morphological, thermal, mechanical, rheological, wettability, and barrier properties (i.e., water vapor permeability, WVP and oxygen transmission rate, OTR). The presence of Si−O−CNC promoted hydrogen bonding interactions with the TPU matrix, affecting the microphase separation and organization of the hard segments. These microstructural changes improved thermal stability, reduced WVP and OTR, and increased tensile properties at lower nanofiller contents (1–3 wt.%). At higher contents, partial nanofiller aggregation was observed, leading to a reduction in mechanical performance. Overall, these results suggest that TPU/Si−O−CNC nanocomposites have promising potential as sustainable food packaging materials. Full article

This study evaluates the performance of major types of conventional and bio-based plastic items commonly used in agriculture to provide comprehensive insights into their key structural and functional properties, including the chemical composition of the polymer matrix and additives, mechanical behavior, and thermal and radiometric properties. Twelve agricultural plastic (AP) items were analyzed: covering mulch films, geotextile ground cover, protection fleece and low tunnel fleece cover, fertilizer sack, fly trap, irrigation pipe, tree binding net, guide for tree, silage film and hay bales protection fabric. This selection of APs also encompasses a broad range of basic polymers, including conventional materials (mainly polyethylene and polypropylene) and bio-based formulations (primarily starch- or lignocellulose-containing blends). Mass spectrometry and infrared spectroscopy analyses were performed to assess polymer composition and additives. Mechanical properties were assessed through tensile and puncture tests; in addition, radiometric, thermogravimetric, surface wettability, water absorption and permeability tests were also performed to assess other relevant physical characteristics. The study identified significant differences among bio-based biodegradable APs and compared them with their conventional polyolefin-based counterparts. Material composition and structure were found to critically influence water interactions, shaping the balance between durability, degradation, and crop protection performance. Notably, bio-based mulch films exhibited higher water vapor permeability (0.6–1.1 × 10⁻¹³ g/m Pa s), reduced penetration resistance (12.1 N) and lowered impact and tensile strengths (21.8 MPa). Water interaction tests showed that the starch-based mulch film displayed very high swelling (above 100%), favoring biodegradation, whereas a biodegradable blend based on polyhydroxybutyrate and polybutylene succinate exhibited minimal swelling (<3%). Material composition and morphology were also key determinants of water vapor transport: dense polymer films provided superior moisture barriers (permeability range 0.013–0.04 × 10⁻¹³ g/m Pa s), while fibrous or biodegradable materials allowed enhanced vapor permeability. The results of this study, highlighting functionality, advantages and limitations of biodegradable APs versus conventional APs, are intended to guide future innovation in AP design, ensuring alignment with both the operational demands of modern agriculture and environmental sustainability goals. The data obtained from this study can support scientific advancements and policy recommendations on the use and management of plastics in agriculture. Full article

This study investigated the rheological, structural, barrier, mechanical, optical, and thermal properties of composite edible films based on citrus pectin and vegetable purées derived from broccoli, cauliflower, pumpkin, carrot, and their blends. Film-forming formulations were characterized in terms of rheological behavior, thickness, microstructure, gas and water vapor permeability, optical and mechanical properties, water contact angle, and thermal stability. The incorporation of vegetable purées significantly modified the properties of the pectin-based matrices. All film-forming solutions exhibited non-Newtonian shear-thinning behavior, with flow behavior index values below unity. The addition of vegetable purées markedly increased viscosity and flow resistance, indicating the formation of more structured systems with stronger intermolecular interactions. Apparent viscosity increased from 0.19 Pa·s in the control sample to 1.41 Pa·s and 1.19 Pa·s in the broccoli (B) and broccoli–cauliflower (B-CF) formulations, respectively, while the consistency coefficient increased from 0.29 to 51.38 Pa·sⁿ. Composite films exhibited lower water contents (0.090–0.114 gH₂O·g_d.m.⁻¹) than the control film (0.179 gH₂O·g_d.m.⁻¹) and were thicker (170–282 μm) than the pure pectin film (125 μm). Barrier analysis revealed a reduction in water vapor permeability from 18.99·10⁻¹⁰ to 10.74–14.69·10⁻¹⁰ g·m⁻¹·s⁻¹·Pa⁻¹ and a decrease in carbon dioxide permeability from 21.95 to 10.47–17.91 GRT. The carrot-containing film exhibited the highest tensile strength (62.17 MPa), whereas the pumpkin–carrot film demonstrated the most favorable combination of barrier and mechanical properties, including the lowest oxygen permeability (6.95 GRT), low water vapor permeability (10.74·10⁻¹⁰ g·m⁻¹·s⁻¹·Pa⁻¹), and high tensile strength (51.02 MPa). Thermogravimetric analysis revealed similar three-stage degradation profiles for all samples, while vegetable incorporation modified moisture release and increased residual mass. The obtained results confirmed the research hypothesis that vegetable-processing by-products can serve as valuable structure-forming components of pectin-based composite films and that interactions between vegetable-derived biopolymers and citrus pectin improve the mechanical, barrier, and functional properties of the resulting materials. Among the tested formulations, the pumpkin–carrot film demonstrated the greatest potential for further development as a biodegradable packaging material. The utilization of vegetable by-products in pectin-based films represents a sustainable approach supporting circular economy principles and the development of environmentally friendly packaging systems. Full article