Search Results (986)

The growing request for more sustainable materials and environmentally friendly nanofabrication methods in the electronics field has recently driven the scientific community in the development of bio-derived materials as an alternative to conventional lithographic resists. In this work, we used chitosan, a biodegradable and biocompatible polysaccharide, as a green direct-write resist material for Atomic Force Microscopy-based nanolithography. Chitosan thin layers were obtained by spin coating and systematically characterized, in terms of thickness and surface roughness, demonstrating nanoscale smoothness and tunable film thickness. Three Pulse–Atomic Force Lithography (P-AFL) approaches, i.e., Constant Pulse, Gradient Pulse, and Raster Pulse AFL methods, were used to pattern nanostructures with constant-depth nanogrooves, variable-depth (2.5D) profile, and three-dimensional nanoholes on chitosan films. The results reveal high pattern fidelity, reproducibility, and tunability of feature dimensions as a function of applied force and scanning direction. Moreover, the RP-AFL technique enabled the fabrication of well-defined 3D nanostructures with depths matching the film thickness, which is a prerequisite for subsequent pattern transfer. This experimental work provided a first proof-of-concept to adopt chitosan as a more sustainable alternative with respect to conventional resists. Moreover, the results highlight P-AFL methods as a versatile and low-impact nanofabrication strategy, contributing to the development of greener micro- and nano-manufacturing technologies. Full article

Chicken feet, an abundant and low-cost poultry by-product rich in collagen, were used to extract gelatin, which was then formulated into active biodegradable films containing food-grade clove essential oil (CEO), glycerol, sorbitol, and Tween 20. Gelatin extraction involved 0.5 M NaOH pretreatment followed by 5% acetic acid extraction at 66 °C, yielding 11.22% gelatin. Eight gelatin–CEO films were prepared by varying the CEO concentration and plasticizer composition. The supplier-declared CEO composition was eugenol-dominant, and antibacterial activity against Escherichia coli, Kluyvera sp., and Enterobacter cloacae was assessed by agar disk diffusion, MIC, and MBC assays, each performed in triplicate. CEO inhibition zones of 22, 14, and 19 mm were recorded against E. coli, Kluyvera sp., and E. cloacae, respectively; the blank 6 mm control disks without oil produced no inhibition halo beyond the disk edge. MIC/MBC values were 5/6, 3/4, and 4/5 mg/mL for the same three strains. All films were continuous, smooth, and peelable; sorbitol-containing formulations were clearer and more flexible than sorbitol-free variants. Water solubility ranged from 37.67% to 48.78%, opacity from 5.26 × 10⁻³ to 9.20 × 10⁻³ A500 mm⁻¹, and thickness from 11.75 to 23.75 µm. Water vapor transfer was undetectable under the gravimetric screening protocol for all formulations. All films showed complete visual disappearance in soil within 6–10 days. In the cherry tomato trial, the best-performing coatings extended acceptable storage from about 5 days (uncoated control) to 10 days at 17–20 °C. Full article

Sour cherry is a highly perishable non-climacteric fruit characterized by rapid postharvest quality deterioration. In this study, a novel biodegradable edible coating system based on chitosan microparticles (CsMPs), green-synthesized selenium microparticles (SeMPs), and thyme essential oil was developed to enhance the postharvest quality and extend the shelf life of sour cherry fruits. The results demonstrated that all coating treatments significantly reduced postharvest quality losses compared to the control. The CsMPs + Oil treatment was most effective in minimizing weight loss (9.44% vs. 13.54% in control at 21 °C) and preserving color parameters, attributed to its barrier properties preventing moisture loss. The incorporation of selenium microparticles markedly enhanced antimicrobial activity, with CsMPs + SeMPs reducing decay rates to 19.5%, compared to 50% in the control, at 21 °C. Additionally, CsMPs + SeMPs effectively suppressed the respiration rate and maintained fruit firmness, indicating delayed metabolic activity. Biochemical analyses revealed that the coatings moderated the increase in total soluble solids, total phenolic content, and total anthocyanin accumulation, while CsMPs + SeMPs was superior in slowing the decline in antioxidant activity. Among treatments, CsMPs + SeMPs and CsMPs + SeMPs + Oil emerged as the most effective formulations. This study highlights the potential of multifunctional edible colloidal coatings as sustainable and eco-friendly alternatives to conventional packaging for extending the shelf life of highly perishable fruits. Full article

Glitter is a distinctive and largely overlooked form of primary microplastic. Unlike more commonly studied microplastics, glitter particles are typically flat, highly reflective, multi-layered, and are composed of polymers such as polyethylene terephthalate, polyvinyl chloride with metallic coatings and a wide range of additives. In response to regulatory restrictions on intentionally added microplastics and increasing consumer demand, “eco-friendly” alternatives based on modified regenerated cellulose, cellulose nanocrystals, or mica have been introduced, although their environmental safety remains insufficiently characterized. This review synthesizes current knowledge on the environmental occurrence and ecotoxicological effects of both conventional and biodegradable glitters. A systematic literature search in Scopus identified 15 peer-reviewed experimental studies meeting predefined inclusion criteria. Evidence spans a wide range of taxa, including bacteria (i.e., Aliivibrio fischeri), microalgae and cyanobacteria (i.e., Phaeodactylum tricornutum, Raphidocelis subcapitata, Microcystis aeruginosa), aquatic plants (i.e., Lemna minor, Egeria densa), marine and freshwater invertebrates as crustaceans (i.e., Daphnia magna), bivalves (i.e., Mytilus galloprovincialis), sea urchins (i.e., Paracentrotus lividus), brine shrimp (Artemia sp.) and terrestrial soil fauna (Eisenia fetida, Folsomia candida). Results indicate that glitter cannot be treated as a uniform stressor: biological responses vary markedly with particle size, shape, colour, polymer type, additive composition, and weathering time, and leachates often exert stronger effects than intact particles. Reported impacts include impaired photosynthesis and growth, oxidative stress, developmental abnormalities, altered energy metabolism, and reduced reproduction. Substantial gaps remain regarding environmental concentrations, ageing processes, mixture effects, and long-term ecological consequences, particularly for biodegradable glitters. Addressing these gaps will require realistic exposure scenarios, mesocosm and field studies, and integrated chemical–biological approaches to support robust risk assessment and safer material design. Full article

Cotton fabrics are widely used due to their comfort and biodegradability; however, their intrinsic hydrophilicity limits their performance in advanced applications. In this work, a fluorine-free approach for imparting durable hydrophobicity to cotton was developed based on thiol-ene crosslinking of polysiloxane networks formed on the fiber surface. Two thiol-functional polysiloxanes differing in –SH group content were combined with four vinyl-functional organosilicon crosslinkers under UV (2,2-dimethoxy-2-phenylacetophenone (DMPA)) and thermal (2,2′-azobis(2-methylpropionitrile) (AIBN)) initiation. FT-IR analysis confirmed the presence of siloxane structures, while SEM-EDS revealed stable silicon- and sulfur-containing layers. SEM observations showed continuous coatings without blocking the textile structure. Water contact angle (WCA) measurements demonstrated that hydrophobic performance strongly depends on thiol content and crosslinker structure, with the highest values obtained for the thiol-rich polysiloxane and tetrafunctional vinyl crosslinker. All modified fabrics exhibited high durability, with minimal changes in WCA and complete droplet stability (1800 s) after washing. In the case of the lower-functionality polysiloxane, an increase in hydrophobicity after washing was observed, attributed to the reorganization of siloxane chains. These results demonstrate that thiol-ene crosslinking provides an effective strategy for designing durable, fluorine-free hydrophobic coatings on cotton. 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

The growing demand for sustainable packaging materials has accelerated interest in biomass-derived carbon fillers as functional reinforcements for biodegradable polymer composites. This review critically evaluates the use of carbon materials produced from agricultural residues, particularly palm kernel shell (PKS) and coconut shell (CS), in biopolymer composite coating films for food packaging applications. Recent thermochemical conversion routes, including carbonization, activation, and catalytic graphitization, are discussed in relation to their influence on filler morphology, porosity, surface chemistry, and graphitic ordering. Particular emphasis is placed on structure–property relationships in composite systems containing matrices such as polylactic acid (PLA), starch, chitosan, gelatin, and polyvinyl alcohol (PVA). Published studies indicate that properly dispersed carbon fillers can improve tensile strength, thermal stability, ultraviolet shielding, and oxygen/water vapor barrier performance through stress-transfer mechanisms and tortuous diffusion pathways. However, excessive filler loading or poor interfacial compatibility frequently causes agglomeration, brittleness, and loss of transparency. Surface modification strategies including oxidation, silanization, and surfactant-assisted dispersion, are therefore reviewed as key approaches to optimize composite performance. Finally, current limitations involving migration safety, process scalability, and the lack of standardized testing protocols are discussed. Overall, PKS- and CS-derived carbon fillers represent promising sustainable additives for next-generation biopolymer composite packaging systems. Full article

Efficient separation of Cu–Mo sulfide minerals from moraine materials remains a major challenge for low-grade, high-moraine Cu–Mo ores. Fine-grained muscovite induces severe slime coating and gangue entrainment, thereby markedly reducing flotation selectivity. In this work, a biodegradable polymer depressant, polyaspartic acid (PASP), was employed to regulate Cu–Mo sulfide flotation under muscovite interference conditions. Microflotation tests, particle size distribution analysis, zeta potential measurements, SEM-EDS observations, contact angle measurements, and XPS analyses were conducted to clarify the dispersion behavior, slime-coating mechanism, and selective adsorption characteristics of PASP. The results demonstrated that PASP selectively depressed muscovite at relatively low dosages while exerting negligible influence on the floatability of chalcopyrite and molybdenite. Notably, at a dosage of 15 mg/L, PASP reduced muscovite recovery by 43.07% and 31.23% more effectively than sodium silicate and sodium hexametaphosphate, respectively, demonstrating superior selective depression efficiency under moraine interference conditions. Particle size distribution and zeta potential analyses confirmed that PASP effectively weakened heterocoagulation and electrostatic attraction between muscovite and sulfide minerals, thereby suppressing slime coating and improving slurry dispersion stability. SEM-EDS and contact angle analyses further revealed that PASP significantly reduced muscovite deposition on sulfide mineral surfaces while maintaining the hydrophobicity of chalcopyrite and molybdenite. High-resolution XPS analysis further indicated that PASP adsorbed onto muscovite mainly through coordination between carboxylate groups and surface Al–OH sites, forming a stable hydrophilic adsorption layer. Overall, PASP provides a low-dosage, highly selective, and biodegradable depressant strategy for mitigating muscovite-induced slime coating and improving the flotation separation of Cu–Mo sulfide ores under moraine interference conditions. Full article

Rising environmental concerns have intensified interest in waste valorisation and the development of sustainable, bio-based materials through green chemistry approaches. In this study, proteins extracted from waste lentil and chickpea seeds were used to develop protein-based films using a range of carboxylic acids as cross-linkers. The acids facilitated protein unfolding and promoted intermolecular interactions, allowing tunable control over mechanical strength, barrier performance, and water resistance. In addition to their structural role, the inherent bioactivity of selected carboxylic acids imparted added functionality to the resulting materials. Physical characterisation and FTIR secondary structure analysis revealed that the acid-type, plasticiser, and, in some cases, protein fraction composition influenced the final material performance. Liquid monocarboxylic acids produced cohesive and flexible films, with tensile strength ranging from ~1 to 23 MPa, with formic acid yielding the strongest films. Lactic acid and its blends improved flexibility and reduced permeability, achieving water vapour permeability (WVP) of 5.76 ± 0.7 × 10⁻¹² g m m⁻² s⁻¹ Pa⁻¹ and oxygen permeability (OP) of 5.8 ± 0.0 × 10⁻¹³ mL m m⁻² s⁻¹ Pa⁻¹ at low acid loadings. In contrast, solid di- and polycarboxylic acids tended to crystallise at higher concentrations. Citric acid was an exception, exhibiting behaviour distinct from the other solid acids and producing clear, crystal-free films with excellent flexibility, showing elongation at break (EAB) up to ~326%. Preliminary proof-of-concept application testing demonstrated the suitability of selected films for vegetable shelf-life extension for up to 17 days and for gradual lactic acid release, supporting their potential use as biodegradable cosmetic mask/patch platforms. Full article

Background/Objectives: Guided bone regeneration (GBR) in dental applications requires scaffolds that possess balanced mechanical strength, controlled biodegradability, and excellent biological performance; therefore, this study aims to develop and evaluate a multilayered biofunctional dental membrane designed to enhance mechanical, biological, and antibacterial performance. Methods: The multilayered membrane was fabricated using sequential electrospinning and electrospraying techniques to form a polycaprolactone (PCL)/Collagen first layer and a polyvinyl alcohol (PVA)/Collagen/Hydroxyapatite (HAp) second layer, topped with a final electrospray coating of PVA/Amoxicillin. Characterization was performed via SEM, FTIR, and EDS, followed by evaluations of tensile properties, swelling behavior, hydrolytic degradation, in vitro drug release, disk diffusion antibacterial activity against Staphylococcus aureus and Escherichia coli, and 7-day L929 fibroblast cytocompatibility (ANOVA/Tukey, p < 0.05). Results: SEM, FTIR, and EDS analyses confirmed uniform nanofiber morphology, homogeneous HAp distribution, and successful integration of bioactive compounds. The membrane exhibited a maximum tensile strength of 15.17 N, strain of 25.24%, and stress of 2.16 MPa, while swelling reached ~100% within 2 h and degradation stabilized around 4% weight loss after 48 h. Drug release profiles showed a rapid amoxicillin release in the first 50 min, plateauing at approximately 4.5 mg/L by 350 min, with distinct antibacterial inhibition zones, and the PCL/Col–PVA/Col/HAp–PVA/Amox group demonstrated the highest cell viability (~140%) after 7 days, significantly exceeding the control groups (p < 0.01). Conclusions: These quantitative findings validate the fabricated multilayered membrane’s potential as a mechanically robust, biodegradable, antibacterial, and bioactive scaffold for advanced guided bone regeneration in dental applications. Full article

The increasing demand for sustainable agricultural inputs has driven interest in biodegradable polymers from agro-industrial residues. Pineapple crown biomass (PCB), a widely available lignocellulosic waste, represents a promising feedstock for producing carboxymethylcellulose (CMC). However, the optimal pulping and bleaching conditions for CMC synthesis from this residue remain underexplored. Nevertheless, the combination of CMC derived from PCB with Bacillus subtilis as a seed coating agent for the bean cultivar has not yet been investigated. Here, we produced cellulosic pulps from PCB using a bioreactor, varying NaOH concentration (1–3%), pulping time (1.5–2.5 h), bleaching volume (55–75 mL) and time (60–120 min). The selected pulping condition (2% NaOH, 1.5 h) yielded pulp with high purity (83.9%) and crystallinity (76.35%). After bleaching (65 mL, 90 min), the material was suitable for CMC synthesis under two conditions: CMC1 and CMC2. CMC2 showed a higher degree of substitution (1.010) than CMC1 (0.620) but led to reduced seed germination (77.67%) due to excessive water retention and fungal growth. In contrast, CMC1, with or without B. subtilis, maintained high germination (91%) and significantly increased seedling length (21.30 cm). We conclude that PCB is a viable feedstock for CMC production, and CMC1 exhibits strong potential as an effective seed coating agent for sustainable agriculture. Full article

To address the global challenge of desertification, it is essential to develop sustainable and biodegradable materials for sand fixation to support ecological restoration in arid regions. In this work, a CNS/PAM biocomposite system was constructed through the supramolecular assembly of highly flexible two-dimensional cellulose nanosheets (CNS) and polyacrylamide (PAM). Benefiting from the flexible layered structure of CNS and the abundant hydroxyl and carboxyl groups on their surface, a conformal coating and an interparticle bridging network were formed via hydrogen bonding and coordination interactions with mineral cations. The introduction of PAM further regulated the hydrogen-bonding network, which improved structural uniformity and mechanical integrity. The resulting composites showed strong resistance to both wind and water erosion (erosion loss < 0.1%) and reached a compressive strength of up to 0.23 MPa, while maintaining good environmental compatibility. This study clarifies the structure–interaction–property relationships of cellulose nanosheet-based supramolecular assemblies and provides a new theoretical basis and practical pathway for designing biodegradable sand-fixing materials. Full article

Miscanthus (Panicum virgatum L.), a biomass material known for its rapid growth and high biomass yield, is considered a suitable resource for producing biobased materials. Nevertheless, the dense and complex structure of Miscanthus hinders its full utilization. In this study, alkaline sulfite pretreatment of Miscanthus was carried out to separate the cellulosic fiber fraction and sulfonated lignin. Then, the fiber fraction was used to prepare biobased seedling pots via the wet foaming technique, and the maximum compressive strength of the prepared seeding pot could reach 1317 kPa. The surface coating of the seeding pot with wood wax oil further improved its hydrophobicity and water resistance. Furthermore, the resulting seedling pot with good biodegradability can be used to replace the petroleum-based plastic seedling pot, which could reduce plastic pollution. In addition, the fractionated sulfonated lignin was directly utilized as a fertilizer, showcasing a 6% increase in root and stem height of cabbage and a 15% rise in biomass (dry weight), compared to the humic acid treatment group. Therefore, this work offers a promising and sustainable strategy for the comprehensive utilization of Miscanthus, which can also be a beneficial reference for the better use of other kinds of lignocellulosic biomass. Full article

Nanocoating technology has emerged as a transformative strategy for enhancing the functional properties of food materials, packaging substrates, and food contact surfaces. This review explores the role of biopolymers as coating materials in nanocoating applications, with a particular focus on the food sector. Inorganic nanomaterials such as silver, titanium dioxide, zinc oxide, and silicon dioxide have been extensively studied for their antimicrobial, photocatalytic, and barrier-enhancing properties; however, concerns regarding toxicity and regulatory compliance continue to limit their direct food contact applications. Biopolymer-based nanocoatings present a safer and more sustainable alternative, offering biodegradability, biocompatibility, and GRAS (Generally Recognized as Safe) status. Key application areas reviewed include edible coatings for fresh and minimally processed fruits, vegetables, meat, cheese, and mushrooms; nanocoating of paper-based and polymeric packaging materials to improve gas barrier, mechanical, moisture resistance, and antimicrobial properties; nanocoating of glass or metal containers and active packaging systems, and nanocoating of food contact surfaces to prevent biofouling and microbial contamination. Recent studies confirm that biopolymer-based nanocoatings, particularly those based on chitosan, cellulose nanofibers, and alginate, can significantly extend shelf life, reduce weight loss, retard oxidation, and maintain sensory quality. Migration of nanomaterials from coatings into food systems is identified as a key safety concern. Challenges including scalability, coating durability, substrate compatibility, and incomplete toxicological profiling are critically discussed. This review underscores the need for standardized testing protocols, comprehensive regulatory frameworks, and continued research into durable, food-grade biopolymer nanocoatings as viable replacements for conventional synthetic coating systems in food preservation and packaging. Full article

Hydrogels (HGs), three-dimensional cross-linked hydrophilic polymer networks, have emerged as a promising class of functional materials for sustainable agriculture due to their exceptional water retention capacity, responsiveness to environmental stimuli, and favorable biocompatibility. This review systematically summarizes the key functional properties of hydrogels and critically examines their multidimensional roles within agricultural systems. The major synergistic benefits of hydrogels are highlighted, including (1) improvement of soil physical structure, chemical properties, and the biological microenvironment, thereby facilitating soil remediation; (2) direct enhancement of seed germination, root development, and crop productivity when employed as soil amendments or seed-coating materials; (3) controlled and sustained release of water, nutrients (N, P, K, and trace elements), and pesticides, leading to significant improvements in resource use efficiency; (4) functional delivery of beneficial microorganisms, enabling precise regulation of their activity and efficacy; and (5) advancement of soilless cultivation technologies through the development of sophisticated hydrogel-based substrates. Furthermore, this review discusses the key challenges that currently limit large-scale agricultural implementation, including insufficient biodegradability, potential ecotoxicological risks, and techno-economic constraints. Finally, future research directions are proposed from an interdisciplinary perspective, emphasizing rational material design, performance optimization, and practical field application. This comprehensive review aims to provide systematic theoretical guidance and practical insights for the development and deployment of hydrogel-based technologies in sustainable agriculture. Full article