Search Results (753)

Eight different types of tea bags were investigated in this work using dynamic light scattering, electrophoretic mobility and nanoparticle tracking analysis methods to determine the concentration and size of released particles from the bag materials at different temperatures and times. Infrared spectroscopy and calorimetric methods confirmed that the bag material consisted of synthetic (nylon or polypropylene) or natural polymers (cellulose). The size of the released particles lies in the range of 200 nm^–1 µm with an initial bimodal distribution and with an average diameter of about 600 nm. The concentration of released particles increases with increasing temperature and brewing time. The released particles of synthetic polymers remain quite stable and are not affected by natural enzymes, while cellulose particles are easily degraded by the proteolytic complex Morikrase. When analyzing the electrophoretic mobility, it was found that the released particles have a negative surface charge, which probably determines the absence of cytotoxicity established on the epithelial cell line Caco-2 even at the maximum values of the observed particle concentrations (14 × 10⁹ particle/L for synthetic polymers and 170 × 10⁹ particle/L for cellulose). Full article

The viscous rheological behavior of suspensions of mixtures of fumed silica nanoparticles (N20) and rod-shaped cellulose nanocrystals (NCC) were studied experimentally. The fumed silica concentration varied from 2 to 11.3 wt% and the NCC concentration varied from 0.99 to 6.73 wt%. The suspensions of pure fumed silica, pure NCC, and mixtures of N20 and NCC were non-Newtonian shear-thinning in nature. The viscosity versus shear rate data of all suspensions of pure and mixed additives could be described satisfactorily by a power-law model. The consistency and flow behavior indices of the suspensions were strongly dependent on the concentrations of both N20 and NCC. While the consistency index increased sharply with the increases in additive (N20 and NCC) concentrations, the flow behavior index generally decreased with the increases in N20 and NCC concentrations. Thus, the suspensions became more shear-thinning with the increases in N20 and NCC concentrations. The shear-thinning of suspensions was due to two different mechanisms: the orientation of rod-shaped cellulose nanocrystals in the flow direction with the increase in shear rate and the break-up of large agglomerates of fumed silica aggregates with the increase in shear rate. Full article

This work reports a one-step, green synthesis of silver-micro cellulose nanocomposite (Ag@Ce NCs) using Azadirachta indica A. Juss leaf extract to load micro-cellulose isolated from peanut shells with silver nanoparticles, followed by comprehensive physicochemical characterization (FTIR, TEM, EDX-SEM, zeta potential, and XRD). The composite has pH_PZC ≈ 5.0 and was tested for simultaneous removal of methylene blue (MB) and safranin O (SO) under batch conditions across various pH levels, doses, contact times, initial concentrations, ionic strengths, and temperatures. The high removal efficiencies observed at pH 10 for MB and 6.0 for SO. The adsorption reached the maximum at 45 min before partially declining, indicating reversible binding on saturated surfaces. Isotherm study favored the Langmuir model, with similar affinities (K_L ≈ 0.106, and 0.110 L/mg) and monolayer capacities of 17.99 mg/g for MB and 14.90 mg/g for SO, suggesting non-selective competition on uniform sites. Kinetic data fitted the pseudo-second-order model, while thermodynamic analysis indicated mainly exothermic and physisorption interactions. Higher ionic strength reduced removal efficiency (at 1.0 M NaCl, %RE ≈ 33–48%), highlighting salt sensitivity typical of electrostatic attraction. The adsorbent maintained about 90% of its initial performance after five adsorption–desorption cycles in 0.1 M H₂SO₄, indicating excellent reusability. Overall, Ag@Ce NCs provide an inexpensive, eco-friendly, and reuseable platform for treating binary mixtures of cationic dyes. Full article

Considering the high stability of water-in-oil (W/O) emulsions, contamination from emulsified pollutants poses a long-term risk to the environment. In this study, hybrid membranes composed of wheat gluten amyloid fibrils (WGAFs) and zein nanoparticles (ZNPs) were prepared and used as a separator to remove emulsified W/O droplets from the oily phase. ZNPs and WGAFs were synthesized through antisolvent method and fibrillation process. Next, a ZNP-functionalized wheat gluten AF/methyl cellulose (ZNP-WGAF/MC) hybrid membrane was fabricated, and its properties were investigated via various analytical techniques. Lastly, the separation efficiency of the ZNP-WGAF/MC hybrid membrane for various W/O emulsions was assessed using microscopy and light scattering. The formation of ZNPs or WGAFs was first verified via spectroscopic and microscopic methods. Our results indicated that the ZNP-WGAF/MC hybrid membranes were synthesized via chemical crosslinking coupled with the casting method. Furthermore, the incorporation of either WGAFs or ZNPs was found to improve the thermal stability and surface hydrophobicity of membranes. Finally, the separation efficiency of the ZNP-WGAF/MC hybrid membranes for various W/O emulsions was determined to be ~87–99%. This research demonstrates the potential of harnessing three-dimensional membranes composed of plant protein-based fibrils and nanoparticles to separate emulsified W/O mixtures. Full article

In this work, ethyl cellulose nanoparticles loaded with rosemary extract (RCL-NPs) were synthesized and utilized to reinforce high-density polyethylene (HDPE) packaging bags as a nanotechnological alternative for rabbit meat preservation. The synthesized RCL-NPs were characterized by DLS and for their stability. The analyzed variables of rabbit meat packaged samples included drained liquid, weight loss, color, pH, texture, and hardness. The total phenolic content (TPC) and antioxidant capacity of rosemary extract were also investigated. The results demonstrated that RCL-NPs were 117.30 nm in size with a negative surface charge (−24.59 mV) and low PDI (0.12). According to the Higuchi model, the release rate of RCL-NPs was sustained from 0 to 24 h. The encapsulation efficiency of the implemented synthesis route was 99.97%. The TPC of rosemary extract was 566.13 ± 1.72 mg GAE/L, whereas their antioxidant activity utilizing the DPPH and FRAP assays was 27.86 ± 0.32 mM Trolox/L and 0.31 mM Trolox/L, respectively. Contrary to control samples, rabbit meat samples conserved in HDPE packaging bags reinforced with RCL-NPs prevent drained liquid and weight loss, while preserving *L (60 ± 2.5–66.10 ± 2.0) and *b (10.67 ± 2.28–11.62 ± 2.39), pH (5.22 ± 0.05–5.80 ± 0.03), and texture (10.37 ± 0.82–0.70 ± 0.50). In the same regard, the developed material conserved the hardness of rabbit meat samples, exhibiting values that ranged from 27.79 ± 7.23 to 27.60 ± 3.05 N during the evaluated period (0–13 days). The retrieved data demonstrate the efficacy of RCL in preserving the quality of rabbit meat when integrated with additional food packaging materials. Full article

This work deals with the preparation of a novel set of ternary polymer composites, where the matrix is a cellulose ether and the reinforcement agent is a 50:50 mixture of TiO₂ nanoparticles with PbCl₂ micropowder (0.25–4 wt%). The attained film samples are investigated from morphological, optical, and electrical points of view to explore the applicative potential as LED encapsulants or flexible dielectric layers for capacitors. Morphological analyses at micro- and nanoscale evidence the level of distribution of the fillers blended within the matrix. UV-VIS spectroscopy and refractometry emphasize that at 0.5 wt% the samples display the best balance between transparency and high refractive index, which matches the applicative criteria for LED encapsulation. The electrical testing with broadband dielectric spectrometer proves that the dielectric constant at 1 kHz of the composite with 4 wt% fillers is enhanced by about 6.63 times in comparison to the neat polymer. This is beneficial for designing eco-friendly and flexible dielectrics for capacitor devices. Full article

Industrial wastewater pollution has reached acute levels in the environment; consequently, scientists are developing new sustainable treatment methods. Lignocellulosic biomass (LB) stands as a promising raw material because it originates from agricultural waste, forestry residues, and energy crop production. This review examines the application of nanomaterials derived from lignocellulosic resources in wastewater management, highlighting their distinctive physical and chemical properties, including a large surface area, adjustable porosity structure, and multifunctional group capability. The collection of nanomaterials incorporating cellulose nanocrystals (CNCs) with lignin nanoparticles, as well as biochar and carbon-based nanostructures, demonstrates high effectiveness in extracting heavy metals, dyes, and organic pollutants through adsorption, membrane filtration, and catalysis mechanisms. Nanomaterials have benefited from recent analytical breakthroughs that improve both their manufacturing potential and eco-friendly character through hybrid catalysis methods and functionalization procedures. This review demonstrates the ability of nanomaterials to simultaneously turn waste into valuable product while cleaning up the environment through their connection to circular bioeconomic principles and the United Nations Sustainable Development Goals (SDGs). This review addresses hurdles related to feedstock variability, production costs, and lifecycle impacts, demonstrating the capability of lignocellulosic nanomaterials to transform wastewater treatment operations while sustaining global sustainability. Full article

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

This study presents an environmentally benign composite hydrogel system by combining polyvinyl alcohol (PVA) with carboxymethyl cellulose derived from jackfruit peel waste (JCMC), subsequently reinforced with graphene oxide (GO) and Kaolin nanoparticles for enhanced Congo red (CR) adsorption. The structural properties of the synthesized hydrogels were comprehensively characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). FTIR analysis confirmed hydrogel formation through hydrogen bonding interactions, while XRD and SEM revealed the uniform dispersion of GO and Kaolin within the polymer matrix, resulting in an improved adsorption performance. Furthermore, the adsorption efficiency of the composite hydrogels was systematically evaluated under varying conditions, including solution pH, contact time, temperature, and initial CR concentration. Optimal CR removal (92.3%) was achieved at pH 8.0, with equilibrium attained within 90 min. The adsorption kinetics were best fitted by the pseudo-second-order model (R² = 0.9998), confirming a chemisorption-dominated process. The equilibrium adsorption data were accurately described by the Langmuir isotherm model, indicating monolayer coverage with an exceptional maximum capacity of 200.80 mg/g. These findings highlight the superior adsorption performance of the PVA/JCMC/GO/Kaolin hydrogels, attributed to their tailored physicochemical properties and synergistic interactions among components. This study offers both sustainable jackfruit peel waste valorization and an effective solution for anionic dye removal in wastewater treatment. Full article

The overuse of nonrenewable resources has motivated intensive research and the development of new types of green bio-based and degradable feedstocks derived from natural sources, such as cellulose derivates, also in nanoforms. The inclusion of such nanoparticles in bio-based polymers with the aim of providing reinforcement is a trend, which, when associated with the incorporation active compounds, creates active packaging suitable for the packaging of highly perishable food, thus contributing to the product’s shelf-life extension. Chitosan (Ch)/sage essential oil (SEO) bionanocomposite reinforced with nanocrystalline cellulose (CNC) was cast as active packaging for the preservation of fresh poultry meat. Meat samples were wrapped in different bioplastics (pristine chitosan, chitosan with commercial CNC, chitosan with CNC obtained from three different lignocellulosic crops, giant reed (G), kenaf (K), and miscanthus (M), chitosan with SEO, and chitosan with SEO and CNC), while unwrapped samples were tested as the control. Periodically, samples were evaluated in terms of their physicochemical properties and microbial growth. Additionally, bionanocomposites were also evaluated in terms of their in situ antimicrobial properties, as well as migration toward food simulants. Meat samples protected with bionanocomposites showed lower levels of microbiological growth (2–3 logs lower than control) and lipid oxidation (20–30% lower than in control), over time. This was attributed to the intrinsic antimicrobial capacity of chitosan and the high oxygen barrier properties of the films resulting from the CNC inclusion. The SEO incorporation did not significantly improve the material’s antimicrobial and antioxidant activity yet interfered directly with the meat’s color as it migrated to its surface. In the in vitro assays, all bionanocomposites demonstrated good antimicrobial activity against B. cereus (reduction of ~8.2 log) and Salmonella Choleraesuis (reduction of ~5–6 log). Through the in vitro migration assay, it was verified that the SEO release rate of phenolic compounds to ethanol 50% (dairy products simulate) was higher than to ethanol 95% (fatty food simulate). Furthermore, these migration tests proved that nanocellulose was capable of delaying SEO migration, thus reducing the negative effect on the meat’s color and the pro-oxidant activity recorded in TBARS. It was concluded that the tested chitosan/nanocellulose bionanocomposites increased the shelf life of fresh poultry meat. Full article

The growing demand for sustainable materials has led to increased interest in biodegradable polymer fibers and nonwoven mats due to their eco-friendly characteristics and potential to reduce plastic pollution. This review highlights how mechanical properties influence the performance and suitability of biodegradable polymer fibers across diverse applications. This covers synthetic polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), polycaprolactone (PCL), polyglycolic acid (PGA), and polyvinyl alcohol (PVA), as well as natural polymers including chitosan, collagen, cellulose, alginate, silk fibroin, and starch-based polymers. A range of fiber production methods is discussed, including electrospinning, centrifugal spinning, spunbonding, melt blowing, melt spinning, and wet spinning, with attention to how each technique influences tensile strength, elongation, and modulus. The review also addresses advances in composite fibers, nanoparticle incorporation, crosslinking methods, and post-processing strategies that improve mechanical behavior. In addition, mechanical testing techniques such as tensile test machine, atomic force microscopy, and dynamic mechanical analysis are examined to show how fabrication parameters influence fiber performance. This review examines the mechanical performance of biodegradable polymer fibers and fibrous mats, emphasizing their potential as sustainable alternatives to conventional materials in applications such as tissue engineering, drug delivery, medical implants, wound dressings, packaging, and filtration. Full article

The present study focuses on the effect of doping KH560-modified cellulose nanocrystals (CNCs) on the electro-optical characteristics of polymer-dispersed liquid crystals (PDLCs). PDLC films were fabricated through the polymerization-initiated phase separation (PIPS) process and doped with CNC nanoparticles at various concentrations. At low concentrations, the CNCs at the interface, by virtue of their unique chiral characteristics, induce an orderly arrangement of liquid crystal molecules. Meanwhile, the interaction between the film’s fiber structure and the liquid crystal droplets brings about an augmentation in the arrangement efficiency. The excellent dispersion of CNCs diminishes the random alignment of liquid crystal molecules and mitigates light scattering. Additionally, it aids in the deflection of the liquid crystal director, facilitating the lubrication of the liquid crystals’ movement. It is remarkable that within the range of relatively lower CNCs doping concentrations, specifically from 0.005 wt% to 0.05 wt%, the PDLC films exhibit lower threshold and saturation voltages, faster response, enhanced viewing angle performance and higher contrast. Full article

This work aimed to advance the knowledge in the field of eco-friendly dielectrics with applicative relevance for future energy-related technologies. New multicomponent composites were prepared by using a cellulose ether/citric acid mixture as the matrix, which was gradually filled with strontium titanate nanoparticles (5–20 wt%). In this case, citric acid can act as a crosslinking agent for the polymer but also can react differently with the other counterparts from the composite as a function of the solvent used (H₂O and H₂O₂). This led to considerable differences in the morphological, thermal, optical, and electrical characteristics due to distinct solvent-driven interactions, as revealed by the infrared spectroscopy investigation. Hence, in contrast to H₂O, the oxidizing activity of H₂O₂ led to changes in the surface morphology, a greater transparency, a greater yellowness, an enhanced refractive index, and higher permittivity. These data provide new pathways to advance the optical and dielectric behavior of eco-compatible materials for energy devices by the careful selection of the composite’s components and the modulation of the molecular interactions via solvent features. Full article

Lanthanide rare earth elements possess significant promise for material applications owing to their distinctive optical and magnetic characteristics, as well as their versatile coordination capabilities. This study introduced a lanthanide-functionalized magnetic nanocellulose composite (NNC@Fe₃O₄@La(OH)₃) for effective phosphorus/nitrogen (P/N) ligand separation. The hybrid material employs the adaptable coordination geometry and strong affinity for oxygen of La³⁺ ions to show enhanced DNA-binding capacity via multi-site coordination with phosphate backbones and bases. This study utilized cellulose as a carrier, which was modified through carboxylation and amination processes employing deep eutectic solvents (DES) and polyethyleneimine. Magnetic nanoparticles and La(OH)₃ were subsequently incorporated into the cellulose via in situ growth. NNC@Fe₃O₄@La(OH)₃ showed a specific surface area of 36.2 m²·g⁻¹ and a magnetic saturation intensity of 37 emu/g, facilitating the formation of ligands with accessible La³⁺ active sites, hence creating mesoporous interfaces that allow for fast separation. NNC@Fe₃O₄@La(OH)₃ showed a significant affinity for DNA, with adsorption capacities reaching 243 mg/g, mostly due to the multistage coordination binding of La³⁺ to the phosphate groups and bases of DNA. Simultaneously, kinetic experiments indicated that the binding process adhered to a pseudo-secondary kinetic model, predominantly dependent on chemisorption. This study developed a unique rare-earth coordination-driven functional hybrid material, which is highly significant for constructing selective separation platforms for P/N-containing ligands. Full article

Developing multifunctional wound dressings with excellent mechanical properties, strong tissue adhesion, and efficient antibacterial activity is crucial for promoting wound healing. This study prepared a novel nanocomposite hydrogel dressing based on sodium alginate-polyacrylic acid dual crosslinking networks, incorporating tannic acid-coated cellulose nanocrystals (TA@CNC) and in-situ reduced silver nanoparticles for multifunctional enhancement. The rigid CNC framework significantly improved mechanical properties (elastic modulus of 146 kPa at 1 wt%), while TA catechol groups provided excellent adhesion (36.4 kPa to pigskin, 122% improvement over pure system) through dynamic hydrogen bonding and coordination interactions. TA served as a green reducing agent for uniform AgNPs loading, with CNC negative charges preventing particle aggregation. Antibacterial studies revealed synergistic effects between TA-induced membrane disruption and Ag⁺-triggered reactive oxygen species generation, achieving >99.5% inhibition against Staphylococcus aureus and Escherichia coli. The TA@CNC-regulated porous structure balanced swelling performance and water vapor transmission, facilitating wound exudate management and moist healing. This composite hydrogel successfully integrates mechanical toughness, tissue adhesion, antibacterial activity, and biocompatibility, providing a novel strategy for advanced wound dressing development. Full article