Search Results (518)

To develop a fully green and non-toxic wood adhesive with improved water resistance and bonding performance for soybean meal (Glycine max (L.) Merr.)-based adhesives, oxidized tannin (OTN) was obtained by the laccase treatment of waxberry tannin (TN), a natural polyphenolic polymer, and then blended with soybean meal (SM) to prepare an oxidized tannin–soybean meal adhesive (OTS). Laccase-mediated oxidation converted the tannin polymer into quinone-rich oxidized polymeric structures, which reacted with amino groups in soybean meal proteins through Michael addition and Schiff base reactions to form a covalently crosslinked polymeric network. Under the optimal conditions of a laccase dosage of 10%, an oxidation time of 6 h, an OTN:SM mass ratio of 0.5:1, and a hot-pressing temperature of 160 °C, plywood bonded with OTS exhibited a wet shear strength of 0.85 MPa at 63 °C, representing a 136% increase over that of the neat soybean meal adhesive, and showed slightly higher bonding performance than the commercial urea-formaldehyde (UF) resin under boiling-water conditions. Structural analyses (FT-IR and XPS) verified quinone formation and carbon–nitrogen single and double bonds. Thermal analyses (DSC and TGA) revealed improved curing reactivity and significantly enhanced thermal stability compared with the neat soybean meal adhesive. Full article

Conventional adhesives for plywood are mostly derived from petroleum-based materials and commonly suffer from formaldehyde emission, posing threats to the environment and human health. In this study, a renewable resource, Xanthoceras sorbifolium Bunge oil, was used as the raw material. A high-performance bio-based adhesive was successfully prepared by synthesizing Xanthoceras sorbifolium Bunge oil dimethacrylate (MXOEA) as a reactive diluent, blending it with acrylated epoxy Xanthoceras sorbifolium Bunge oil (AEXO), and introducing 2-isocyanatoethyl methacrylate (IEM) to enhance crosslinking. The effects of the MXOEA/AEXO ratio and the IEM addition level on the properties of the adhesive and the resulting plywood were systematically investigated. The results showed that when the mass ratio of AEXO to MXOEA was 3:7, and the IEM content was 10%, the adhesive exhibited the best bonding performance: the resulting plywood achieved a modulus of rupture of 68.85 MPa, a modulus of elasticity of 8086 MPa, and dry and wet bonding strengths of 3.21 MPa and 2.32 MPa, respectively. Mechanistic analysis indicated that the introduction of IEM moderately reduced the viscosity of the adhesive system. Meanwhile, the isocyanate groups in IEM reacted with the hydroxyl groups on the wood surface, forming a chemical crosslinking structure at the adhesive-wood interface, which is considered one of the reasons for the improved mechanical properties of the plywood. This study provides a formaldehyde-free, high-performance bio-based adhesive derived from Xanthoceras sorbifolium Bunge oil for the field of wood-based composites. Full article

To develop cosmetic film-forming agents that combine sustainability with functionality, this study synthesized a series of bio-based polyols using epoxidized soybean oil (ESO) as raw material through acid-catalyzed ring-opening reactions. These polyols partially replaced petroleum-based polyols and reacted with isophorone diisocyanate (IPDI). By incorporating β-cyclodextrin (β-CD), a water-based polyurethane (CPS-ESO) was successfully developed that combines degradability with active ingredient delivery capability. Experiments demonstrated that the resulting CPS-M film exhibits excellent water repellency (contact angle 66.7°), mechanical properties (tensile strength 14.21 MPa, elongation at break 229.42%), adhesion (Level 0), and breathability, while displaying controllable degradation behavior under both enzymatic and alkaline hydrolysis conditions. Due to the cavity structure of β-cyclodextrin, this material efficiently loaded resveratrol (RES) at a loading rate of 0.16%. Formulated into a setting spray (F1), the product demonstrated outstanding makeup longevity (lowest ΔE value after water/sweat immersion), anti-friction performance (ΔE value after friction only one-third of the control group), and antioxidant activity (DPPH scavenging rate of 86.25%), with RES remaining stable under high-temperature storage conditions. This study provides new insights for designing green multifunctional cosmetic film-forming agents. Full article

This study examines how 3D-printing orientation affects the mechanical behavior and environmental impact of polymer materials and heterogeneous PLA/TPU composites. Tensile properties of PLA, TPU, and PLA/TPU heterogeneous samples were systematically compared in horizontal and vertical printing orientations. Results show that printing orientation governs mechanical performance: vertical printing generally reduces ductility and exhibits unstable post-peak behavior, with heterogeneous samples performing worse than their single-material counterparts. In contrast, horizontal printing enhances strength, ductility, and energy absorption due to continuous load transfer along the filament path, improved interlayer adhesion, and larger effective contact areas. Specifically, TPU demonstrates higher ductility and energy absorption in the horizontal orientation, while PLA achieves higher strength but lower ductility; both materials degrade substantially in the vertical orientation. For heterogeneous composites, vertical printing yields the poorest outcomes due to load transfer across multiple perpendicular interfaces and thermal shrinkage mismatch, which promote crack initiation and propagation. Horizontal printing delivers an optimal balance of strength and toughness via stronger interface bonding. Life cycle assessment (LCA) indicates that horizontal printing reduces environmental burdens by lowering energy consumption and waste, whereas vertical printing amplifies these impacts, particularly for TPU and composite systems. Based on these findings, we recommend employing horizontally printed PLA/TPU heterogeneous composites to achieve favorable load paths and interface integrity while prioritizing bio-based PLA to enhance sustainability. Full article

Surface-enhanced Raman spectroscopy (SERS) amplifies Raman scattering by placing molecules in the near-field of plasmonic nanostructures, enabling label-free molecular fingerprinting. While attractive for living cell phenotyping, many cellular SERS works rely on internalized colloidal nanoparticles, leading to variable uptake/localization, aggregation-driven hotspot fluctuations, and potential cellular perturbation. Here, we report a chip-like Au/SiO₂ nanolaminate SERS substrate that supports direct culture and label-free measurements of living cells on spatially defined hotspots without nanoparticle uptake. The periodic nanolaminate forms dense nanogaps and is engineered for 785 nm excitation, providing uniform enhancement over a large, culture-compatible area with high hotspot uniformity. By engineering the cell–substrate nano–bio interface, the platform enables reproducible acquisition of intrinsic cellular vibrational fingerprints under physiological conditions without Raman tags. Using MCF-7 and MDA-MB-231 breast cancer cells, we collected hundreds of spectra per line, and MDA-MB-231 exhibited broader spectral variations, indicating greater heterogeneity. Principal component analysis and linear discriminant analysis achieved 99% classification accuracy for MCF-7 and MDA-MB-231, and bright-field imaging confirmed preserved adhesion and canonical morphologies. This chip-based, label-free living cell SERS platform enables scalable, nonperturbative phenotyping and may support rapid malignancy classification and treatment response screening across subtle cancer states. Full article

To address the hazards posed by formaldehyde emissions from wood-based products to human health and the indoor environment, research on wood adhesives has focused on developing green and eco-friendly alternatives. However, the limited water resistance and bonding strength of bio-based or glyoxal-based adhesives have hindered their practical application. In this work, a co-condensation method was employed to prepare glyoxal-based co-condensation adhesive incorporating starch and a small amount of chitosan as synergistic reinforcing agents to enhance their cross-linking extent. Considering cost control, the starch content was varied to adjust the adhesive properties. When the molar ratio of glyoxal to urea was 2:1 and the mass ratio of starch to urea was 0.5:1, the adhesive exhibited optimal bonding strength, reaching 1.48 MPa after immersion in cold water for 24 h and 0.91 MPa after treatment in 63 °C hot water for 3 h. These values exceeded the requirements of the Chinese national standard (GB/T 9846-2015, ≥0.7 MPa). Structural analysis indicated Schiff base and aldol condensation reactions among amino groups in chitosan and urea and hydroxyl and aldehyde groups in starch and glyoxal, forming chemical covalent cross-links that contributed to improved water resistance and bonding strength of plywood samples. Furthermore, the excellent penetration ability of the adhesive could promote the formation of a uniform and dense cross-linked network under hot-pressing conditions, thereby enhancing the overall performance of the plywood. Full article

This study investigates the development of polyvinyl alcohol (PVA)-based nanocomposite films reinforced with cellulose nanofibrils (CNFs) and biobased additives derived from blueberry pruning waste for sustainable food packaging applications. The nanocomposites were fabricated via solvent casting and evaluated in terms of their thermal and antimicrobial properties. Thermogravimetric analysis (TGA/DTG) revealed that the thermal degradation of the nanocomposites occurs through overlapping processes of PVA and CNFs, with maximum degradation temperatures ranging from 273 to 293 °C depending on the formulation. The incorporation of CNFs modified the degradation pathway and promoted the formation of thermally stable carbonaceous residues, while TEMPO-oxidized samples exhibited a decrease in degradation onset (14–24 °C) due to the presence of oxidized surface groups. Remarkably, the nanocomposites exhibited significant antimicrobial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria without the incorporation of external antimicrobial agents. Bleached PVA/CNFs films achieved complete growth inhibition (100%), while lignin-containing and additive-modified systems showed selective antibacterial behavior. Zeta potential analysis confirmed a negatively charged CNF surface (−35.3 mV), which may contribute to electrostatic interactions with bacterial membranes. Scanning electron microscopy (SEM) revealed nanostructured surfaces with exposed fibrillar networks that promote bacterial adhesion and immobilization, supporting a contact-active antimicrobial mechanism. These findings demonstrate that the antimicrobial performance of PVA/CNFs nanocomposites is governed by intrinsic physicochemical and topographical properties rather than by the release of antimicrobial agents. This approach provides a safer and more sustainable strategy for the design of active food packaging materials. Full article

This study develops a unified multiscale–machine learning framework to interpret and predict thermo-mechanical wear regime transitions in MWCNT- and nanoclay-reinforced bio-based epoxy composites. A physics-informed master wear formulation integrating real contact mechanics, geometry-dependent shear transfer, interfacial adhesion energetics, and fracture-controlled matrix detachment was combined with interpretable machine learning analytics on a unified tribological dataset. In the CNT system, increasing loading from 0.1 to 0.4 wt.% enhanced interfacial adhesion energy density from 0.00813 to 0.01906 J/m², resulting in a monotonic reduction in the wear rate from 0.00918 to 0.00613 mm³/N·m (~33% reduction). In contrast, nanoclay exhibited an optimum behavior, with a minimum wear at 0.25 wt.% (0.000093 mm³/N·m; 7.9% reduction vs. neat clay baseline), followed by deterioration at a higher loading due to dispersion loss. The unified probabilistic regime classification of low-wear conditions (k < 0.007 mm³/N·m) achieved an ROC − AUC = 0.9256 and balanced accuracy = 94.3%, with thermo-mechanical severity identified as the dominant regime-switching driver. Reinforcement identity significantly modulated regime stability, confirming distinct shear transfer (Carbon Nano Tubes(CNT)) and confinement/tribofilm (clay) mechanisms within a common mathematical framework. By enabling the durability-oriented design of bio-based tribological systems and extending component service life through predictive stability mapping, this work contributes to resource-efficient materials engineering and reduced lifecycle waste, supporting Sustainable Development Goals SDG 9 (Industry, Innovation and Infrastructure), SDG 12 (Responsible Consumption and Production), and SDG 13 (Climate Action). Full article

A major drawback of many proposed biobased alternatives of the most commonly used petroleum-based packaging materials is their relatively poor physical properties. In order to develop more viable alternative packaging materials, these properties need to be modified, while maintaining and improving the other desired characteristics. An investigation was done on corona-charged curcumin-containing PLA films to determine how the addition of the polyphenol impacts its physical properties. Measurements of the surface potential of the films were performed, as was the impact of low pressure on the electret properties. The effect of the corona discharge treatment on the physicochemistry of the surface of composite PLA films was investigated systematically using some complementary surface analytical techniques, such as surface wettability and morphology by scanning electron microscopy. The mechanical properties and conductance of the films were also investigated. A dependency of the decay of the surface potential on the film type and the polarity of the corona was found. It was also established that modifying the surface of the films with corona discharge can cause an increase in their wettability and surface free energy, while also improving their adhesion properties. This is caused by the creation of polar functional groups on the film surface during the charging process. It was also determined that the introduction of curcumin in the PLA films decreases their stiffness, which may be caused by a decrease in intramolecular cohesion. Full article

This work focused on the investigation of sulfonated lignin as a novel and sustainable reinforcing filler for polyamide 6 (PA6) composites. Different formulations were thus prepared by melt compounding, varying the lignin content (5, 10, and 20 wt%). The interaction between lignin and PA6 was systematically studied through rheological, structural, morphological, thermo-mechanical, and flammability tests. Rheological measurements showed an increase in the complex viscosity and viscoelastic moduli with increasing lignin content, suggesting restricted polymer chain mobility and the formation of strong physical interactions between the molten PA6 and the lignin particles. Microstructural observations through FESEM highlighted a good dispersion of lignin particles and efficient filler–matrix interfacial adhesion. Moreover, the addition of lignin significantly increased the tensile stiffness of the composites (up to 3.4 GPa), and a lignin content of 10 wt% enhanced the tensile strength up to 58.4 MPa (i.e., +45% compared to neat PA6) without compromising the ductility. Finally, UL-94 tests revealed an improvement in flame retardancy at higher lignin contents due to the intrinsic char-forming ability of this filler. These results demonstrated that lignin could be an effective multifunctional bio-based filler that can improve the thermo-mechanical performance of PA6 without the need for compatibilizing agents. Full article

The valorization of agro-industrial byproducts as sources of functional polysaccharides is a promising strategy for developing sustainable materials. In this study, cellulose was extracted and purified from rice husk and apple pomace through sequential alkaline and bleaching treatments. Then it was chemically modified via TEMPO-mediated oxidation to obtain cellulose nanofibers (TOCNFs) with cellulose yields ranging from 23.8 to 32.4% for rice husk and 9.3–13.8% for apple pomace. Owing to its higher recovery and structural regularity, rice husk was selected for surface modification with 3-aminopropyltriethoxysilane (APTES). The resulting TOCNFs exhibited an average width of 8 nm and a carboxyl content of 0.48 mmol g⁻¹. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nitrogen determination (1.72 mg g⁻¹) confirmed the presence of aminosilane functionalities. APTES-modified TOCNFs were incorporated as active components to develop hybrid poly(vinyl acetate) (PVA) adhesives synthesized via in situ heterogeneous water-based polymerization. The influence of TOCNF surface chemistry and sodium dodecyl sulfate (SDS) on latex particle size, rheological behavior, and adhesive performance was systematically investigated. Latex particle size increased from 193 nm (PVA-SDS) to 625 nm with TOCNF-APTES and decreased to 247 nm upon SDS addition. Rheological analysis revealed pronounced shear-thinning behavior associated with the formation of percolated nanofibrillar networks, with low-shear viscosity increasing up to 477 Pa·s for TOCNF–APTES and decreasing to 370 Pa·s with SDS. Lap-shear testing (ASTM D905) showed substantial improvements in adhesive strength, reaching up to 250 kPa compared to PVA-SDS. These results demonstrate that surface-modified CNFs act not only as mechanical reinforcements but also as interfacially active components governing polymerization behavior, rheology, and adhesive performance. This exploratory study provides a proof-of-concept for the development of sustainable wood adhesives from agro-industrial byproducts. Full article

The increasing demand for sustainable and environmentally friendly construction materials has spurred interest in biopolymer composites reinforced with agricultural waste. Rice husk (RH), a byproduct of rice milling, is abundant and rich in lignocellulosic fibers and silica, making it excellent for use in fiber-reinforced biopolymers. The novelty of this study lies in its integrated and construction-oriented evaluation of rice husk (RH)-reinforced biopolymers, combining mechanical, thermal, environmental, and economic perspectives within a single framework. The study introduces a novel comparative approach by benchmarking multiple polymer matrices-including PP, recycled HDPE, epoxy, PLA, and bio-binders-under unified quantitative performance criteria. Another key novelty is the identification of the dual functional role of silica-rich RH in simultaneously enhancing structural strength and flame retardancy while contributing to carbon emission reduction. With a high silica content (15–20%) and lignocellulosic structure, RH serves as a natural filler that enhances the performance of polymer matrices such as polypropylene (PP), epoxy, polylactic acid (PLA), and recycled polyethylene. Mechanically, RH-reinforced composites demonstrate significant improvements in tensile, flexural, and impact strength. For example, PP composites with NaOH-treated RH and coffee husks achieved tensile strengths between 27.4 MPa and 37.4 MPa, with corresponding Young’s modulus values ranging from 1656 MPa to 2247.8 MPa. Recycled HDPE-RH blends reached tensile strengths up to 74 MPa and flexural values of 39 MPa, validating their structural applicability. Epoxy matrices embedded with 0.45 wt.% RH nanofibers showed degradation thresholds of 411 °C and 678 °C, reflecting substantial thermal resistance. Flame retardancy is further improved by the presence of RH biochar, which leads to reduced peak heat release rate (PHRR) and enhanced char formation. In building insulation applications, RH-based composites exhibit low thermal conductivity values between 0.08 and 0.14 W/m·K, contributing to energy efficiency. Economically, RH reduces material costs by 30–40%, while environmentally, its integration lowers carbon emissions in PP composites by up to 10%, and promotes biodegradability. Despite challenges such as moisture absorption and interfacial adhesion, these can be mitigated through alkali treatment, compatibilizers (e.g., MAPP), or hybrid reinforcement strategies. Full article

Recycled cellulosic fiber (RCF) composites offer significant potential to reduce environmental burdens associated with virgin fiber production; however, their broader adoption remains limited by feedstock variability, recycling-induced degradation, and uncertainty regarding long-term performance. This review critically synthesizes recent advances in RCF composites using a structure–processing–performance–sustainability framework, treating recycled fibers as secondary materials with distinct morphological, chemical, and mechanical characteristics rather than direct substitutes for virgin reinforcements. Emphasis is placed on the effects of fiber shortening, surface damage, moisture sensitivity, and altered surface chemistry on interfacial adhesion, load transfer efficiency, durability, and failure mechanisms. The analysis reveals that many reported performance discrepancies arise from poorly defined structure–property relationships and the absence of standardized characterization, grading, and durability testing protocols for recycled fibers. Addressing these gaps enables more reliable predictive modeling and application-specific material design. Beyond mechanical behavior, the review evaluates various critical factors for integration into higher-value applications such as durability under realistic service conditions, including environmental aging, fire performance, and long-term stability. Emerging strategies such as hybrid reinforcement, environmentally benign surface functionalization, smart functionalities, and recyclable or bio-based matrices are assessed for their potential to enhance multifunctionality and circularity. Overall, the findings indicate that RCF composites can meaningfully contribute to circular material systems if materials design, performance validation, and life-cycle assessment are integrated systematically. Advancing standardized evaluation and aligning materials innovation with circular economy principles are essential to transition RCF composites from downcycled applications to reliable, performance-oriented components in sustainable engineering systems. Full article

Biofilm production by foodborne pathogens poses significant challenges to food safety and quality, leading to contamination, deterioration, and substantial economic losses for the food industry. Traditional biofilm control methods, such as chemical disinfectants, antibiotics, and preservatives, are sometimes ineffective against persistent biofilms, raising concerns about antimicrobial resistance and the accumulation of chemical residues. Lactic acid bacteria (LAB) have emerged as attractive natural biocontrol agents due to their ability to produce a wide range of antimicrobial secondary metabolites, including bacteriocins, organic acids, hydrogen peroxide, and biosurfactants. This paper thoroughly examines the effect of LAB and their metabolites in preventing and destroying biofilms generated by bacteria relevant to food systems, including Listeria monocytogenes, Salmonella enterica, Escherichia coli, and Pseudomonas spp. The processes causing LAB-mediated biofilm attenuation are thoroughly investigated, including competition for nutrients and adhesion sites, interference with quorum sensing (QS), and metabolic inhibition. Furthermore, recent breakthroughs in LAB-based techniques for food preservation and facility hygiene are discussed, including the creation of LAB-derived antimicrobial coatings, biosurfactant-based cleaning agents, and probiotic bio-coatings for industrial sanitation. The incorporation of nanotechnology has enhanced LAB applications by enabling the creation of LAB-mediated metallic nanoparticles and encapsulated formulations that improve metabolite stability and facilitate controlled release. The combination of LAB metabolites, natural preservatives, and eco-friendly materials in active packaging provides sustainable alternatives to synthetic chemicals. Overall, this review emphasizes the potential of LAB and their bioactive derivatives as environmentally friendly and practical tools for controlling biofilms and preserving food, thereby promoting safer food production systems and accelerating the food industry’s transition to green, sustainable technologies. Full article

This study presents the fabrication and optimization of eco-efficient epoxy composites reinforced with ground natural stone fillers, namely pebble, sandstone, and marble, at loadings of up to 15.6 wt.%. Low content of a bio-based modifier, modified castor oil (MCO ≈ 0.5 wt.%), is incorporated to improve filler dispersion, processing behavior, and matrix–filler interfacial compatibility. The composites are designed to enhance mechanical, thermal, and dielectric performance using low-cost, abundant, and environmentally sustainable constituents. An experimental optimization approach is employed to evaluate and optimize bulk density, Shore D hardness, thermal conductivity, dielectric constant, and tensile strength. The results demonstrate that pebble-reinforced composites exhibit the highest tensile strength (≈30 MPa) and surface hardness (≈82 Shore D), which are attributed to the angular morphology and high intrinsic rigidity of pebble particles. Marble-filled systems show superior thermal stability, with residual mass increasing from approximately 2.5 wt.% for neat epoxy to over 11 wt.% at 550 °C, owing to the thermally stable calcium carbonate phase. In contrast, sandstone-reinforced composites exhibit the lowest dielectric constant (≈3.2), indicating enhanced electrical insulation capability. Fourier–transform infrared spectroscopy (FTIR) results confirm that the epoxy network structure is preserved upon filler incorporation, while MCO promotes improved interfacial interactions through physical interactions. Thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) reveal enhanced thermal resistance, reduced microvoid formation, and improved filler–matrix adhesion at optimal filler contents of approximately 3.5 wt.%. Full article