Search Results (231)

In this study, multifunctional nanocomposite membranes were fabricated using biopolymeric polylactic acid (PLA) and cellulose acetate (CA) composites via electrospinning. The hydrophobic nanocomposite membranes were reinforced with varying concentrations of silicon dioxide (silica/SiO₂) nanoparticles. The developed PLA–CA–SiO₂ nanofibrous membranes are characterized using field emission scanning electron microscopy (FE- energy-dispersive SEM), energy-dispersive X-ray (EDX), elemental mapping, X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FT–IR), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. Various physical and mechanical properties of the bio-nanocomposite membrane, such as tensile testing, infrared thermal imaging, ultraviolet–visible spectroscopy (UV–Vis), water contact angle, hydrostatic pressure resistance, and breathability are also investigated. The analysis revealed that a small concentration of silica nanoparticles improves the morphological, mechanical, and thermal characteristics of nanocomposite membranes. The addition of silica nanoparticles improves the UV (A & B), visible and infrared blocking efficiency while also enhancing the waterproofness of protective textiles. The PLA–CA–SiO₂ biopolymer nanocomposite membrane has a fibrous microstructure and demonstrated the tensile strength of 11.2 MPa, a Young’s modulus of 329 MPa, an elongation at break of 98.5%, a hydrostatic pressure resistance of 27 kPa, and a water contact angle of 143.7°. The developed electrospun composite membranes with improved properties provide strong potential to replace petroleum-based membranes with biopolymer-based alternatives, promising improved and wider usage for bio-related applications. Full article

Novel polyester–polyurethane polymeric materials were formulated by combining a natural aliphatic polyester, poly(3-hydroxybutyrate) (P3HB), with a synthetic aliphatic polyurethane via melt blending. The resulting fully biodegradable compositions were functionally modified through the incorporation of urea, with the aim of enabling post-consumer utilization of the material residues as nitrogen-rich fertilizers. The fabrication process was systematically established and optimized, focusing on homogeneous blending and processability. Comprehensive mechanical characterization—including tensile strength, impact resistance, and Shore hardness—was performed. Among the tested formulations, composites containing 1 wt.% urea demonstrated superior mechanical performance and optimal processing behavior. Fourier-transform infrared (FTIR) spectroscopy was employed to investigate molecular-level interactions between polymeric phases and urea, while scanning electron microscopy (SEM) was utilized to assess the morphological characteristics of the resulting biocompositions. Comparative analyses of the physico-mechanical properties and biodegradability were conducted among the urea-modified compositions, binary P3HB–polyurethane blends, and neat P3HB. The observed improvements in mechanical integrity and functional biodegradability suggest that the developed urea-enriched compositions are promising candidates for the fabrication of eco-friendly seedling pots via injection molding technology. Full article

Biopolymers and bio-based plastics, such as polylactic acid (PLA) and polybutylene succinate (PBS), are recognized as environmentally friendly materials and are widely used, especially in the packaging industry. The purpose of this study was to assess the degradation of PLA- and PBS-based formulations in the forms of granules and films under controlled composting conditions at a laboratory scale. Biodegradation tests of bio-based materials were conducted under controlled aerobic conditions, following the standard EVS-EN ISO 14855-1:2012. Scanning electron microscopy (SEM) was performed using a high-resolution Zeiss Ultra 55 scanning electron microscope to analyze the samples. After the six-month laboratory-scale composting experiment, it was observed that the PLA-based materials degraded by 47.46–98.34%, while the PBS-based materials exhibited a final degradation degree of 34.15–80.36%. Additionally, the PLA-based compounds displayed a variable total organic carbon (TOC) content ranging from 38% to 56%. In contrast, the PBS-based compounds exhibited a more consistent TOC content, with a narrow range from 53% to 54%. These findings demonstrate that bioplastics can contribute to reducing plastic waste through controlled composting, but their degradation efficiency depends on the material composition and environmental conditions. Future efforts should optimize bioplastic formulations and composting systems while developing supportive policies for wider adoption. Full article

Herein, electrospun nanofibers composed of polyaniline (PANI), polyethylene oxide (PEO), and Luffa cylindrica (LC) cellulose, reinforced with titanium dioxide (TiO₂) nanoparticles, were synthesized via electrospinning to investigate the effect of TiO₂ nanoparticles on PANI/PEO/LC nanocomposites and the effect of conductivity on nanofiber morphology. Cellulose extracted from luffa was added to the PANI/PEO copolymer solution, and two different ratios of TiO₂ were mixed into the PANI/PEO/LC biocomposite. The morphological, vibrational, and thermal characteristics of biocomposites were systematically investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). As anticipated, the presence of TiO₂ enhanced the electrical conductivity of biocomposites, while the addition of Luffa cellulose further improved the conductivity of the cellulose-based nanofibers. FTIR analysis confirmed chemical interactions between Luffa cellulose and PANI/PEO matrix, as evidenced by the broadening of the hydroxyl (OH) absorption band at 3500–3200 cm⁻¹. Additionally, the emergence of characteristic peaks within the 400–1000 cm⁻¹ range in the PANI/PEO/LC/TiO₂ spectra signified Ti–O–Ti and Ti–O–C vibrations, confirming the incorporation of TiO₂ into the biocomposite. SEM images of the biocomposites reveal that the thickness of nanofibers decreases by adding Luffa to PANI/PEO nanofibers because of the nanofibers branching. In addition, when blending TiO₂ nanoparticles with the PANI/PEO/LC biocomposite, this increment continued and obtained thinner and smother nanofibers. Furthermore, the incorporation of cellulose slightly improved the crystallinity of the nanofibers, while TiO₂ contributed to the enhanced crystallinity of the biocomposite according to the XRD and DCS results. Similarly, the TGA results supported the DSC results regarding the increasing thermal stability of the biocomposite nanofibers with TiO₂ nanoparticles. These findings demonstrate the potential of PANI/PEO/LC/TiO₂ nanofibers for advanced applications requiring conductive and structurally optimized biomaterials, e.g., for use in humidity or volatile organic compound (VOC) sensors, especially where flexibility and environmental sustainability are required. Full article

Hydroxyapatite (HAP) is the most widely accepted biomaterial for repairing bone tissue defects, demonstrating excellent biocompatibility and bioactivity that promote new bone formation. Zirconia (ZrO₂), known for its strength and fracture toughness, is commonly used to reinforce ceramics. In this study, magnesium oxide (MgO) served as a stabilizer for zirconia, resulting in magnesia partially stabilized zirconia (Mg-PSZ). Both Mg-PSZ and HAP were synthesized via coprecipitation and mixed in specific ratios to create composites through a ceramic method involving mixing, compaction, and sintering at 1100 °C. The samples were characterized using techniques such as X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Structural analyses confirmed the presence of both monoclinic and tetragonal zirconia phases. Besides, the increased wt.% HAP in the composites produced distinct peaks for hexagonal HAP. Crystallite sizes ranged from 27.45 nm to 31.5 nm, and surface morphology was homogeneous with small pores. Elements such as calcium, phosphorus, magnesium, zirconium, and oxygen were detected in all samples. This research also examined microhardness changes in the materials. The findings revealed enhancement in microhardness for the biocomposite with higher zirconia content, 90Mg-PSZ/10HAP sample, with the smallest average pore size, highlighting its potential for biomedical applications. Full article

This research aims to synthesize a novel hydrogel bio-composite based on natural clay, sodium alginate (Na-AL), and iota-carrageenan as adsorbents to remove phosphate ions from aqueous solutions. The adsorbents were characterized by a variety of techniques, such as Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy coupled with energy dispersive X-rays (SEM-EDX), and the determination of point zero charge (PZC). This research investigated how the adsorption process is influenced by parameters such as adsorbent dose, contact time, solution pH, and temperature. In this study, we used four isotherms and four kinetic models to investigate phosphate ion removal on the prepared bio-composite. The results showed that the second-order kinetic (PSO) model is the best model for describing the adsorption process. The findings demonstrate that the R² values are highly significant in both the Langmuir and Freundlich models (very close to 1). This suggests that Langmuir and Freundlich models, with a diversity of adsorption sites, promote the adsorption of phosphate ions. The maximum adsorbed amounts of phosphate ions by the bio-composite used were 140.84 mg/g for H₂PO₄⁻ ions and 105.26 mg/g for HPO₄²⁻ ions from the batch system. The positive ∆H° confirms the endothermic and physical nature of adsorption, in agreement with experimental results. Negative ∆G° values indicate spontaneity, while the positive ∆S° reflects increased disorder at the solid–liquid interface during phosphate uptake. The main parameters, including adsorbent dosage (mg), contact time (min), and initial concentration (mg/L), were tuned using the Box–Behnken design of the response surface methodology (BBD-RSM) to achieve the optimum conditions. The reliability of the constructed models is demonstrated by their high correlation coefficients (R²). An R² value of 0.9714 suggests that the model explains 97.14% of the variability in adsorption efficiency (%), which reflects its strong predictive capability and reliability. Finally, the adsorption behavior of phosphate ions on the prepared bio-composite beads was analyzed using an artificial neural network (ANN) to predict the process efficiency. The ANN model accurately predicted the adsorption of phosphate ions onto the bio-composite, with a strong correlation (R² = 0.974) between the predicted and experimental results. Full article

This study investigates the coupled hygrothermal behavior of mycelium-based composites (MBCs) as a function of their microstructural organization, governed by fungal species, substrate type, additive incorporation, and treatment method. Eleven composite formulations were selected and characterized using a multi-scale experimental approach, combining scanning electron microscopy, dynamic vapor sorption, vapor permeability tests, capillary uptake measurements, and transient thermal conductivity analysis. SEM analysis revealed that Ganoderma lucidum forms dense and interconnected hyphal networks, whereas Trametes versicolor generates looser, localized structures. These morphological differences directly influence water vapor transport and heat conduction. Additive-enriched composites exhibited up to 21.8% higher moisture uptake at 90% RH, while straw-based composites demonstrated higher capillary uptake and free water saturation (up to 704 kg/m³), indicating enhanced moisture sensitivity. In contrast, hemp-based formulations with Ganoderma lucidum showed reduced sorption and vapor permeability due to limited pore interconnectivity. Thermal conductivity varied nonlinearly with temperature and moisture content. Fitting the experimental data with an exponential model revealed a moisture sensitivity coefficient thirty times lower for GHOP compared to VHOP, highlighting the stabilizing effect of a compact microstructure. The distinction between total and effective porosity emerged as a key factor in explaining discrepancies between apparent and functional moisture behavior. These findings demonstrate that hygric and thermal properties in MBCs are governed not by porosity alone, but by the geometry and connectivity of the internal fungal network. Optimizing these structural features enables fine control overheat and mass transfer, laying the groundwork for the development of high-performance, bio-based insulation materials. Full article

This study develops highly flexible, biodegradable polymer blends using bio-based polyhydroxyalkanoate (PHA) polymers for Fused Deposition Modeling (FDM) 3D printing. A Design of Experiment (DoE) approach optimized blend compositions by varying crystallinity levels of three PHAs, processed via twin-screw extrusion. Rheological analysis revealed that PHA blends exhibited 30–50% lower viscosity than PLA at low shear rates, ensuring improved processability. Tensile testing confirmed favorable mechanical properties, with elongation at break exceeding 2000%, significantly surpassing PLA (29%). Differential scanning calorimetry (DSC) indicated partial miscibility and crystallinity reductions of up to 50%, influencing printability. Optimized 3D printing parameters demonstrated minimal warping for blends with crystallinity below 18%, ensuring high-dimensional stability. During home composting tests, PHA blends showed significant degradation within two months, whereas PLA remained intact. Scanning electron microscopy (SEM) confirmed microbial degradation. Cytotoxicity tests demonstrated that the blends were non-toxic, supporting applications in tissue engineering. These findings highlight the potential of PHA-based blends as sustainable, high-performance materials for biomedical, packaging, and environmental applications. Full article

The objective of this study was to explore the potential of creating advanced insulating biocomposites using waste almond and hazelnut shells as particulate fillers, combined with a geopolymer binder, to develop sustainable materials with minimal environmental impact. Optimal conditions for the preparation of biocomposites were determined by measuring the compressive strengths. The aforementioned optimal conditions included a geopolymer to waste nutshell mass ratio of 2, room-temperature curing, and the use of metakaolin geopolymers activated with potassium solutions. Notably, the highest compressive strengths of 4.1 MPa for hazelnut shells biocomposite and 6.4 MPa for almond shells biocomposite were obtained with milk of lime pretreatment at 80 °C for 1 h. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) and Fourier transform infrared spectroscopy (FTIR) analyses revealed better adhesion, as well as improved geopolymer gel polymerization. Furthermore, thermal conductivity and diffusivity measurements demonstrated values characteristic of insulating materials, reinforcing their potential for eco-friendly construction applications. Full article

Calcium silicate-based sealers (CSBS) vary in chemical composition, which can influence treatment outcomes. Therefore, the study aimed at comparing several commercially available CSBS regarding microstructure and elemental characterization. Four CSBS (AH Plus Bioceramic Sealer, BioRoot RCS, BioRoot Flow, TotalFill BC Sealer) and a control resin-based sealer (AH Plus) were evaluated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray powder diffraction analysis (XRD). The specimens were analyzed after setting (SEM, EDX, XRD), as well as after 7 (SEM) and 28 days (SEM, EDX) of incubation in Hank’s balanced salt solution. AH Plus exhibited a uniform matrix and small amounts of calcium (Ca), significantly decreasing after incubation. In contrast, CSBSs exhibited crystalline forms on the surface and increased Ca content, significantly increasing after 28 days of incubation. The main crystalline phase for all tested CSBS was zirconium oxide, while for ERBS it was calcium tungstate. In conclusion, the amount of calcium increased on the surface of CSBSs after incubation, which alkalinized the pH, promoting mineralization, apatite formation, and antibacterial potential. Despite this, the formation of a hydroxyapatite layer was not demonstrated, possibly due to the high dissolution potential of CSBSs. Full article

The development of biocomposites derived from wheat flour and Hermetia illucens (black soldier fly) larvae flour presents a viable and sustainable alternative to conventional petroleum-based plastics, which contribute significantly to environmental degradation. The incorporation of cellulose nanocrystals (CNCs) is anticipated to enhance the functional properties of these materials, particularly for food packaging applications. The objective of this study was to develop and characterise biodegradable composites formulated from wheat and larvae flours, and to evaluate the effect of CNC addition on their physicochemical, mechanical, and structural properties. The biocomposites were produced using compression moulding and subsequently subjected to comprehensive characterisation. The results indicated that the addition of CNCs markedly improved the optical, barrier, and mechanical properties of the composites. These improvements render the materials suitable for packaging systems requiring moisture retention and reduced permeability to water vapour. From a mechanical perspective, composites incorporating CNCs exhibited increased tensile strength and stiffness, although a reduction in elongation at break was observed when compared to those prepared solely with larvae flour (LF). Scanning electron microscopy (SEM) analyses revealed that higher concentrations of larvae flour yielded composites with fewer surface fractures and reduced porosity. In conclusion, the utilisation of wheat and insect larvae flours, in combination with cellulose nanocrystals, represents an innovative and environmentally responsible approach for the development of biodegradable composites suitable for eco-friendly food packaging applications. Full article

In this work, poly(L-lactic acid)/thermoplastic alginate (PLA/TPA) biocomposites were prepared through a melt blending method. The TPA was initially prepared using glycerol as a plasticizer. The effects of TPA content on the interactions between blend components, thermal properties, phase morphology, mechanical properties, hydrophilicity, and biodegradation properties of biocomposites were systematically investigated. Fourier transform infrared (FTIR) spectroscopy analysis corroborated the interaction between the blend components. The addition of TPA enhanced the nucleating effect for PLA, as determined by differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) revealed poor phase compatibility between the PLA and TPA phases. The thermal stability and mechanical properties of the biocomposites decreased with the addition of TPA, as demonstrated by thermogravimetric analysis (TGA) and tensile tests, respectively. The hydrophilicity and soil burial degradation rate of biocomposites increased significantly as the TPA content increased. These results indicated that PLA/TPA biocomposites degraded faster than pure PLA, making them suitable for single-use packaging, but this necessitates careful optimization of TPA content to balance mechanical properties and soil burial degradation rate for practical single-use applications. Full article

The algae-derived bio-binder (ADBB) from hydrothermal liquefaction has been reported to be an effective and sustainable new alternative to petroleum-based curing agents for epoxy resin. However, there is still room for the epoxy/ADBB system to attain the comprehensive mechanical performance of conventional epoxy-based nanocomposites, typically reinforced with surface-functionalized nanofillers (e.g., glass nanoparticles (GNPs)) by petroleum-based silane coupling agents. Herein, we explored the use of ADBB as an innovative surface-modifying agent to functionalize GNPs and evaluated the potential of ADBB surface-functionalized GNPs (ADBB-GNPs) as a reinforcing agent in the epoxy/ADBB matrix nanocomposite by comparing them to pristine GNPs and (3-aminopropyl) triethoxysilane (APTES) (a popular silane coupling agent) surface-modified GNPs (APTES-GNPs). The surface functionalization of GNPs with ADBB was carried out and characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). Material performance including tensile, flexural, and Izod impact properties and thermal properties of the resulting epoxy/ADBB nanocomposites were investigated by corresponding ASTM mechanical test standards and thermogravimetric analysis (TGA). Our results revealed that the ADBB is a sustainable and effective surface-modifying agent that can functionalize GNPs. The obtained ADBB-GNPs significantly improved the mechanical performance of the epoxy/ADBB system at ultra-low loading (0.5 wt.%) by up to 42% and the maximum decomposition rate temperature increased from 419 °C to 422 °C, both of which outperformed APTES-GNPs. This research sheds light on developing sustainable surface-modifying agents for nanofillers to create high-performance sustainable polymer composite materials. Full article

Poly(lactic acid) (PLA) is a biodegradable thermoplastic polymer used in various applications, including food packaging, 3D printing, textiles, and biomedical devices. Nevertheless, it presents several limitations, such as high hydrophobicity, low gas barrier properties, UV sensitivity, and brittleness. To overcome this issue, in this study, biochar (BC) produced through pyrolysis of bio-mass waste was incorporated (1 wt.%, 2wt.%, and 3 wt.%—PLA 1, PLA 2, and PLA 3) to enhance thermal and mechanical properties of PLA composites. The impact of pyrolysis temperature on the kinetic parameters, physicochemical characteristics, and structural properties of banana and orange peels for use as biochar added to PLA was investigated. The biomass waste such as banana and orange peels were characterized by proximal analysis and thermogravimetric analysis (TGA); meanwhile, the PLA composites were characterized by tensile straight, TGA, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results indicated that the presence of biochar improved hygroscopic characteristics and Tg temperature from 62.98 °C for 1 wt.% to 80.29 °C for 3 wt.%. Additionally, it was found that the tensile strength of the composites increased by almost 30% for PLA 3 compared with PLA 1. The Young’s modulus also increased from 194.334 MPa for PLA1 to 388.314 MPa for PLA3. However, the elongation decreased from 14.179 (PLA 1) to 7.240 mm (PLA3), and the maximum thermal degradation temperature shifted to lower temperatures ranging from 366 °C for PLA-1 to 345 °C for PLA-3 samples, respectively. From surface analysis, it was observed that the surface of these samples was relatively smooth, but small microcluster BC aggregates were visible, especially for the PLA 3 composite. In conclusion, the incorporation of biochar into PLA is a promising method for enhancing material performance while maintaining environmental sustainability by recycling biomass waste. Full article

Money Art is a growing contemporary practice where artists transform banknotes into unique visual works. While conceptually powerful, these artworks present significant conservation challenges due to their fragile substrates and complex material compositions. This study investigates the degradation behaviour of UniPosca acrylic markers applied on zero-euro banknotes, drawing on the techniques of artist RichardHTT, and explores bio-based protective strategies suitable for their preservation. Laboratory samples were prepared to replicate the original artwork and subjected to accelerated ageing. A multi-analytical approach was employed, including multispectral imaging, Fourier trasform infrared (FTIR) and Raman spectroscopy, and scanning electron microscopy (SEM-EDS) colorimetric analysis. Thickness and adhesion properties were assessed with contact micrometry and peel tests, while wettability was evaluated through static contact angle measurements. Four biopolymer coatings, chitosan and chitosan–nanocellulose films with varying CNC concentrations, were evaluated for their transparency, mechanical stability, and compatibility with the substrate. Results showed that painted areas, especially those with blue and black pigments, experienced marked degradation, while, after coating application, samples demonstrated improved chromatic stability, hydrophobicity, and adhesion. Importantly, all coatings were fully removable via enzymatic cleaning with α-amylase, confirming their reversibility. This research highlights the potential of chitosan-based biocomposites as conservation materials for non-traditional artworks and contributes to developing tailored, reversible strategies for contemporary art preservation. Full article