Search Results (902)

This study aimed to characterize corn (CS), wolf fruit (WF), and butterfly lily (BL) starches; to develop bioactive coatings from pure starches and their binary and ternary blends; and to evaluate the synergistic effects of these formulations on the physiological quality of common bean seeds. Films were prepared by thermocompression (80 °C, 6 min, 3 t) of film-forming solutions obtained via microwave processing and formulated using a simplex-centroid mixture design. The starches were characterized in terms of amylose content, Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry, Rapid Visco Analyser, while the films were evaluated for thickness, water solubility, and water vapor permeability. The film-forming solutions were applied as coatings, and seed physiological quality was assessed through germination, first count, seedling length, and dry mass. BL exhibited higher gelatinization temperatures and produced films with adequate thickness and moderate permeability, indicating greater structural stability. The CS:BL blend produced films with balanced hydration, promoting rapid and uniform water uptake. Coatings based on BL and CS:BL showed the highest germination percentages, whereas CS:WF resulted in lower physiological performance. These results demonstrate that film properties directly influence seed vigor and germination. BL, alone or blended with CS, represents a promising starch-based material for seed coating, promoting high physiological quality and environmentally friendly characteristics. Full article

Biodegradable films based on polysaccharides have attracted attention as sustainable alternatives for food preservation. In this study, films and films were developed using cassava starch, chitosan, and grape seed extract, either individually or in polymeric blends, and their physicochemical, mechanical, microstructural, and preservative properties were evaluated. The films were applied to peeled shrimp stored under refrigeration for six days. Microbiological analysis showed a reduction in aerobic mesophilic bacterial counts in coated samples, indicating improved preservation. Films containing cassava starch and chitosan provided greater pH stability during storage. Film characterization revealed that grape seed extract influenced thickness and solubility, particularly in chitosan-based formulations. Cassava starch films exhibited the best water vapor permeability, while blended systems demonstrated improved mechanical performance. The highest tensile strength was observed for the chitosan-based film with extract, whereas starch-containing blends showed balanced strength and flexibility. Scanning electron microscopy revealed more cohesive and continuous structures in polymer blends, while extract-only films presented internal voids, explaining their lower mechanical resistance. Thus, the synergistic combination of cassava starch and chitosan, modulated by grape seed extract, produced films with suitable barrier, mechanical, and structural properties. These biodegradable polymeric films show promising potential for extending the shelf life of refrigerated shrimp and for application in sustainable food packaging. Full article

In the surface protection of stone and brick cultural heritage, a primary challenge is that traditional polymeric coatings are prone to photooxidative degradation under ultraviolet (UV) irradiation, and the resulting aged fragments readily block the substrate micropores, leading to a loss of “breathability”. To address the performance conflict among waterproofing, breathability, and weather resistance, this study prepared few-layer Ti₃C₂T_X MXene using a minimally intensive layer delamination (MILD) method. The poor compatibility between MXene and the fluorosilicone (FPS) resin matrix was effectively resolved through covalent modification with a silane coupling agent (KH-550). Results demonstrate that at an ultralow loading (0.5 wt%), the functionalized f-MXene is uniformly dispersed within the resin. This structure not only spontaneously constructs a hierarchical rough architecture on the surface that imparts high hydrophobicity (water contact angle of 131.6°), but its internal “labyrinth effect” also effectively blocks corrosive media. Simultaneously, the intrinsic water vapor transmission rate of the substrate is effectively maintained (with a reduction of less than 3%), and no visually perceptible color difference is generated (∆E = 1.2). Mechanically, f-MXene relies on interfacial interactions to act as a “nano-skeleton” for stress transfer, thereby increasing the uniaxial compressive strength of fragile limestone by 32.4%. Optical and spectroscopic characterizations further elucidate its anti-aging mechanism: f-MXene not only provides broadband UV shielding but also exhibits highly efficient radical scavenging activity during long-term UV aging. After 400 h of aging, the concentrations of hydroxyl and superoxide anion radicals within the system are significantly reduced, blocking the photooxidative chain reaction from the source. This work develops a composite protective material system for stone cultural heritage that simultaneously integrates high moisture permeability, minimal visual intervention, and long-term antioxidant performance. Full article

This study investigates the effect of gamma irradiation on the physicochemical, mechanical, and antimicrobial properties of biodegradable composite films based on modified cassava starch/gelatin (GS) and wheat gluten/gelatin (GG), including their active formulations with 2% potassium sorbate (GS2S and GG2S, respectively). Films were produced by casting and irradiated at 2–32 kGy. Irradiation modulated the structure–property relationships of starch–protein matrices in a dose-dependent manner. In GG systems, tensile strength increased while elongation decreased, indicating enhanced intermolecular interactions. At higher doses (16–32 kGy), excessive rigidity was observed, whereas lower doses (2–8 kGy) provided a more favorable balance between strength and flexibility. Water vapor permeability decreased in selected formulations, while solubility results indicated the coexistence of crosslinking and chain scission mechanisms. Among the tested conditions, 2 kGy was identified as the optimal dose. Despite the incorporation of 2% potassium sorbate, antimicrobial performance remained limited, with modest inhibition against Wallemia sebi and negligible effects on Aspergillus chevalieri and Aspergillus montevidensis. HPLC analysis demonstrated a significant reduction in sorbate release after irradiation (up to ~80%), indicating that restricted mass transfer, rather than intrinsic antimicrobial inefficiency, governs the observed behavior. The main novelty of this work lies in demonstrating that irradiation-induced structural modifications improve mechanical and barrier properties but simultaneously hinder active compound release. This decoupling between structural performance and functional activity highlights a critical limitation in irradiated active films. Overall, gamma irradiation at 2 kGy is effective for tuning material properties; however, controlling release kinetics is essential to achieve functional antimicrobial performance in biodegradable active packaging systems. Full article

Developing a biodegradable film with integrated mechanical robustness and multifunctionality remains a significant challenge for sustainable food packaging. Herein, a pectin/carboxymethyl cellulose composite film (PNZ_xC) incorporated with zinc oxide nanoparticles (ZnO) was fabricated via a solution casting method to achieve the synergistic enhancement of structural and functional properties. ZnO exhibits dual functionality within the polymer matrix, serving both as a reinforcing filler and as a coordination interaction node via interactions with carboxyl groups. At an optimal loading, the PNZ₂C film demonstrates a uniform dispersion of nanoparticles, facilitating the development of a dense network structure and enhancing intermolecular interactions. Consequently, the film showed reduced water vapor and oxygen permeability, attributable to the formation of tortuous diffusion pathways, together with increased surface hydrophobicity and a significantly improved tensile strength of 25.4 MPa. Enhanced thermal stability and excellent UV-blocking performance were also achieved. Notably, the optimized film demonstrated superior preservation performance in blueberry storage, effectively reducing moisture loss and delaying quality deterioration compared with the control. These findings provide new insights into the structure–property relationships of ZnO–polysaccharide nanocomposite systems and highlight a viable strategy for designing high-performance, biodegradable packaging materials with integrated multifunctionality. Full article

The formation of stereocomplex (SC) crystallites in poly(L-lactide) (PLLA)/poly(D-lactide) (PDLA) blends has attracted significant attention due to its potential to enhance the performance of biodegradable polymer films. In this study, the effect of solvent evaporation kinetics on the crystallization behavior, microstructure, and functional properties of PLLA/PDLA blend films was systematically investigated. Films with various blend ratios were prepared under open-lid (fast evaporation) and closed-lid (slow evaporation) conditions. Differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS) analyses revealed that slow solvent evaporation significantly promotes stereocomplex formation, particularly at the equimolar (50:50) composition, resulting in a higher degree of crystallinity and a more compact structure compared to fast evaporation conditions. These structural changes were directly correlated with improved functional properties. The optimized PLLA/PDLA (50:50) films exhibited a substantial reduction in water vapor permeability from 22.7 to 3.11 g·mm/m²·day·kPa (~86% decrease) and a marked decrease in microbial growth, as evidenced by reduced total plate count (TPC) values compared to neat polymers. The enhanced barrier performance and reduced microbial proliferation were attributed to the reduced free volume and increased tortuosity associated with densely packed stereocomplex crystallites, as supported by DSC and WAXD results. These findings demonstrate the importance of solvent evaporation kinetics in tailoring structure–property relationships to control stereocomplex formation and multiscale structural organization, providing a practical strategy for biodegradable packaging films. Full article

Bird feathers possess functions such as water resistance, thermal insulation, and air permeability, providing inspiration for the design of functional fabrics. Based on the functional differentiation of different feather regions and the structural constraints associated with these functions, this study selected down feathers, feather vanes, hooklets, and fluffy feather filament node structures as biomimetic prototypes. Four biomimetic knitted structures were designed for outdoor environments with significant temperature fluctuations and for the thermo-moisture comfort needs of older adults. Through macro- and micro-structural feature extraction, three-dimensional modeling, and experimental testing, a multi-parameter evaluation system covering water resistance, thermal resistance, thermal insulation rate, air permeability, moisture vapor transmission, and moisture management was established to systematically evaluate the thermo-moisture regulation performance of the fabrics. The results showed that each structure exhibited distinct performance advantages: Structure 1 demonstrated the best thermal insulation performance; Structure 2 showed relatively superior water resistance and outstanding air permeability; Structure 4 exhibited relatively superior moisture vapor transmission and moisture management performance; and Structure 3 achieved the highest gray relational optimality value, indicating a relatively balanced thermo-moisture regulation capability. Among all performance indicators, air permeability showed the highest correlation with the knitted structures. Based on these results, and considering regional differences in heat generation and sweating across different body parts of older adults, this study further explored zonal application strategies for elderly outdoor clothing to improve wearing comfort and functionality under environments with fluctuating thermal conditions. Full article

Studies have shown that oceanic surface-water salinity varies across the globe and changes over time, while atmospheric water-vapor levels have also increased in recent decades. Evaporation from ocean and inland waters is controlled primarily by meteorological forcing, but the thermodynamic state of the water body also matters. In saline waters, dissolved solutes reduce water activity and thereby reduce the equilibrium tendency of water molecules to enter the vapor phase. In this study, the authors’ coefficient-less aqueous osmotic potential equation was used to examine the thermodynamic effect of representative oceanic salinity differences on evaporative tendency. Calculations were made for recorded surface-water salinities ranging from 31 to 38 kg·m⁻³ of dissolved solutes at an average temperature of 20 °C. Computed osmotic potentials ranged from −2.257 to −2.708 MPa. The corresponding semi-permeable membrane interface pressures ranged from 8.935 to 8.484 MPa, indicating an approximately 5% difference across the selected oceanic salinity range. The interface pressure calculated for solute-free water (11.192 MPa) was more than 24% higher than for the seawater cases considered. These results suggest that salinity acts as a secondary thermodynamic modifier of evaporation potential, whereas radiative, aerodynamic, humidity, and temperature controls remain dominant in determining actual evaporation fluxes. The results also indicate that freshwater bodies and changing land-based evaporative sources may contribute differently to atmospheric water vapor than saline ocean waters. The framework presented here is intended to complement, rather than replace, established evaporation formulations by clarifying how salinity-related osmotic effects can modify the water-side boundary condition. Full article

In this study, fully bio-based oligomers of butylene succinate (OBS) with different molecular weights (low: L-OBS, medium: M-OBS and high: H-OBS) were incorporated into poly(butylene succinate) (PBS) by melt mixing at varying loadings of 5–15 wt%. Then, PBS/OBS films were obtained by thermo-compression and characterized to assess their suitability for sustainable food packaging. Thus, OBS were homogeneously incorporated into PBS matrix and modulated the thermal, mechanical, and barrier properties of the PBS. L-OBS (Mn = 1150 g·mol⁻¹) plasticized the amorphous PBS, depending on its concentration, more effectively than M-OBS (Mn: 8700 g·mol⁻¹) and H-OBS (Mn: 18,650 g·mol⁻¹), as deduced from the thermo-mechanical analysis. In every case, OBS enhanced crystallinity, mainly L-OBS, which reduced the film strength and increased water vapor permeability, depending on its concentration. In contrast, H-OBS improved mechanical strength, stiffness, and barrier performance. In all cases, X-ray diffraction confirmed the preservation of the PBS’s monoclinic crystalline structure but slightly shifted the diffraction angle depending on the ratio of the end-chain groups in the blend, thus reflecting the contribution of OBS in the crystalline lattice. Finally, oligomer incorporation resulted in an overall migration increase in different food simulants, impairing their application in packaging. Full article

Chickpea (Cicer arietinum L.) flour is a promising raw material for bio-based packaging due to its protein and polyphenol content. In this study, thermocompressed chickpea flour sheets were reinforced with cellulose nanocrystals (CNCs) to improve their barrier, mechanical, optical, thermal, and structural properties. Preliminary trials identified 22% moisture as the most suitable condition for consistent sheet formation. CNC was incorporated at 0, 2.5, 5.0, and 7.5% (w/w). Thermocompression reduced the measurable phenolic fractions, although antioxidant activity was not significantly affected. CNC markedly reduced water vapor permeability from 5.16 × 10⁻¹⁰ in the control to 5.93 × 10⁻¹² g∙m⁻¹∙s⁻¹∙Pa⁻¹ at 7.5% CNC. Tensile strength and Young’s modulus increased with CNC loading, whereas elongation at break was highest at intermediate concentrations. Optical characterization showed changes in transmittance and opacity. Thermal analysis indicated that CNC modified the DSC thermal event, whereas only minor differences were observed in the TGA profile. SEM, DSC, XRD, and FTIR analyses suggested changes in morphology and thermo-structural organization. Overall, CNC improved barrier and mechanical performance, supporting the potential of these sheets as a material for semirigid biodegradable packaging applications. Full article

The application of lignin-based films is often restricted by traditional processing methods that rely on toxic organic solvents and harsh chemical reagents, which result in poor compatibility with the polymer matrix and difficulty balancing transparency, barrier, and toughness. Here, lignin was green-modified by ternary deep eutectic solvent (choline chloride-lactic acid-ethanol), and ZnO hybrids with cellulose nanocrystals (CNC) as anchor points were introduced to realize the stability and uniform dispersion of ZnO in the polyvinyl alcohol (PVA) matrix. The prepared composite film maintains a transmittance of about 78% at 800 nm while achieving a wide spectrum of ultraviolet shielding. The barrier properties of the film were markedly improved: the water vapor permeability (WVP) decreased to 0.24 × 10⁻⁷ g·m⁻¹·h⁻¹·Pa⁻¹, and the oxygen permeability (OTR) to 6.98 cm³·m⁻²·24 h⁻¹·0.1 MPa⁻¹. In addition, the mechanical flexibility and durability of the material were significantly improved, as evidenced by a tensile strain of 109%. In the insurance experiment, compared with the blank film, the browning degree and weight loss of the composite film were relatively low. The scalable and low-solvent consumption route provides a practical idea for the application of lignin in food preservation. Full article

In this study, bean starch films were developed and treated with dielectric barrier discharge (DBD) cold plasma (5 min (DBD5), 10 min (DBD10), and 15 min (DBD15)) and pulsed light (PL) radiation (4 J cm⁻² (PL4), 8 J cm⁻² (PL8), and 12 J cm⁻² (PL12)), and the effects of these treatments on the physical, barrier, mechanical, morphological, and structural properties were evaluated, as well as the practical application of the films in bread storage for 7 days. Both treatments significantly modified the film properties (p < 0.05). Film thickness decreased from 95 µm (control) to 87 µm (PL12), while solubility was reduced from 39.40% (control) to 25.32% (PL12), indicating improved water resistance. Reductions in water vapor permeability (WVP) were also observed, with a more pronounced effect for PL12 (approximately 55% reduction compared to the control). The contact angle increased from 58.30° (control) to 67.76° (PL12), indicating a moderate increase in surface hydrophobicity. The DBD cold plasma treatment increased tensile strength (up to 16.05 MPa in DBD15) and reduced elongation (44.72%), whereas PL, especially at PL8, increased flexibility (60.36%). Morphological analyses indicated increased surface roughness for DBD-treated films, while structural analyses suggested subtle changes in molecular organization rather than the formation of well-defined crystalline domains. During bread storage, the treated films, particularly PL12, were significantly more effective than the control in delaying bread staling (final firmness of 6.67 N vs. 11.82 N), reducing mass loss (5.66% vs. 12.66%), and maintaining higher water activity, thereby better preserving product quality. Overall, both treatments showed potential for tailoring film properties: DBD was more effective in enhancing mechanical strength, while PL promoted improvements in barrier properties and practical performance. Therefore, physical treatments, particularly PL, represent promising strategies to overcome intrinsic limitations of starch-based films and to develop packaging materials with potential applications in bakery product preservation. Full article

Environmental pollution from plastics is largely driven by inadequate waste management, particularly in food packaging that relies heavily on petroleum-derived materials. This study utilized gelatin capsule waste (GCW) as a sustainable biopolymer and incorporated yellow peacock flower extract (YPE), obtained via ultrasound-assisted extraction (UAE), at various concentrations (0–2%, w/v) to develop biodegradable films with enhanced functional and antioxidant properties. The main phenolic constituents of YPE were flavonoid aglycones and their glycosylated derivatives. YPE showed total phenolic content of 98.44–129.34 mg GAE/g dry extract, with ABTS, DPPH, and FRAP antioxidant activities ranging from 5.51 to 8.11, 3.17–7.63, and 3.86–5.82 mg TE/g dry extract, respectively. Incorporation of YPE into GCW films significantly improved light barrier properties, thermal stability, mechanical strength, and antioxidant activity, along with a reduction in water vapor permeability and an increase in contact angle, indicating enhanced film hydrophobicity. All films exhibited excellent biodegradability, with complete disintegration within 15 days under soil burial conditions. Films containing 2% YPE (GF4) showed significantly higher thickness, tensile strength, and thermal stability, along with increased opacity, compared with the control (GF0), indicating a reinforcing effect. FTIR analysis revealed the interaction between protein and phenolic compounds from YPE. In a food application model, GF4 film pouches (5 × 5 cm²) effectively delayed oxidative deterioration of dried shrimp during storage at 25 ± 2 °C for 15 days. These findings highlight YPE as a promising bioactive ingredient for biodegradable active packaging and demonstrate the feasibility of GCW as a sustainable biopolymer for eco-friendly films. Full article

Valorization of abundant agricultural residues, particularly lignin, provides the opportunity to divert waste streams while enabling materials to inherently exhibit durable functionalities, including UV-blocking, antioxidant properties and water repellency. This study reports the side-by-side valorization of hemp hurd (HL) and corn stover lignin (CL), extracted using the CELF process, into electrospun lignin/nylon 6 nanofiber membranes, establishing how lignin botanical origin, molecular weight (M_w), and blend ratio govern multifunctional performance relevant to protective membranes in textiles. Lignin–nylon 6 hydrogen bonding was regulated by the OH content and accessibility, M_w, and purity, and influenced the functional properties of the fibers. While stronger in low-M_w nanofibers, these interactions were weakest in low-M_w HL samples due to the lowest purity, despite the highest OH content. Fibers with low-M_w lignin yielded finer, brittle fibers with higher UV blocking, whereas high-M_w fractions showed higher antioxidant performance due to decreased interactions with nylon 6. Overall, lignin/nylon 6 nanofiber membranes delivered biobased UPF 50+ performance, 55–61% antioxidant activity at the optimal concentration, and exhibited tunable water repellency via fraction selection and the blend ratio. In combination with a nanofiber architecture, these membranes can impart durable inherent functionality onto textile substrates without affecting their existing properties, including water vapor permeability, without the use of chemical finishing, while utilizing renewable resources from agricultural residues. Full article

This study investigates the development of mixed matrix membranes based on polyethersulfone incorporated with attapulgite for gas separation applications, addressing the existing gap regarding the use of this mineral in dense membranes obtained exclusively by solvent evaporation and its combined effects on microstructure and transport. The membranes were prepared by phase inversion via solvent evaporation, using solvent/polymer ratios of 75/25 and 80/20 and a thickness of 0.25 mm. The solutions were evaluated in terms of viscosity, and the membranes were characterized by structural techniques such as X-ray diffraction (XRD), atomic force microscope (AFM), contact angle, mechanical properties (tensile testing), and water vapor permeation. The results showed that attapulgite incorporation promoted a reduction in surface roughness (up to ~40%) and a decrease in contact angle (from ~89° to ~68°), indicating increased hydrophilicity. In addition, water vapor permeability was influenced in a non-linear manner, with optimized performance observed at 3 wt% filler loading. Solution viscosities remained within ranges suitable for processing. Structural analyses indicated compatibility between the phases, while morphology changes dependent on filler content were decisive for transport behavior. It is concluded that attapulgite is a promising additive for fine-tuning membrane properties, enabling optimization of the sorption–diffusion balance and improvement of membrane performance in separation applications. Full article