Search Results (378)

In this study, we report a reproducible in situ photochemical method for the simultaneous synthesis of metallic and hybrid metal/metal oxide nanoparticles (NPs) within a UV–curable polymer matrix. A series of epoxy diacrylate-based formulations (BEA) was prepared, consisting of Epoxy diacrylate, Di(Ethylene glycol)ethyl ether acrylate (DEGEEA), and Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (BAPO), which served as a Type I photoinitiator. These formulations were designed to enable the simultaneous photopolymerization and photoreduction of metal precursors at various Ag⁺/Co²⁺ ratios, resulting in nanocomposites containing in situ-formed Ag NPs, cobalt oxide NPs, and hybrid Ag–Co₃O₄ nanostructures. The photochemical, magnetic, and dielectric properties of the resulting nanocomposites were evaluated in comparison with those of the pure polymer using UV–Vis and Fourier Transform Infrared Spectroscopy (FT-IR), Photo-Differential Scanning Calorimetry (Photo-DSC), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Impedance Analysis, and Vibrating Sample Magnetometry (VSM). Photo-DSC studies revealed that the highest conversion values were obtained for the BEA-Ag₁Co₁, BEA-Co, and BEA-Ag₁Co₂ samples, demonstrating that the presence of Co₃O₄ NPs enhances polymerization efficiency because of cobalt species participating in redox-assisted radical generation under UV irradiation, increasing the number of initiating radicals and leading to faster curing and higher final conversion. On the other hand, the Ag NPs, due to the SPR band formation at around 400 nm, compete with photoinitiator absorbance and result in a gradual decrease in conversion values. Crystal structures of the NPs were confirmed by XRD analyses. The dielectric and magnetic characteristics of the nanocomposites suggest potential applicability in energy-storage systems, electromagnetic interference mitigation, radar-absorbing materials, and related multifunctional electronic applications. Full article

Herein, we propose a simple and cost-effective method for fabricating moderate-sensitivity surface-enhanced Raman scattering (SERS) substrates using Cu-plasma polymer fluorocarbon (Cu-PPFC) nanocomposite films fabricated through RF sputtering. The use of a composite target composed of carbon nanotube (CNT), Cu, and polytetrafluoroethylene (PTFE) powders (5:60–80:35–15 wt%) offers the advantage of the simple fabrication of moderate-sensitivity SERS substrates with a single cathode compared to co-sputtering. X-ray photoelectron spectroscopy (XPS) revealed that the film surface was partially composed of metallic Cu with Cu-F bonds and Cu–O bonds, confirming the coexistence of the conducting and plasmon-active domains. UV-VIS spectroscopy revealed a distinct absorption peak at approximately 680 nm, indicating the excitation of localized surface plasmon resonances in the Cu nanoclusters embedded in the plasma polymer fluorocarbon (PPFC) matrix. Atomic force microscopy and grazing incidence small-angle X-ray scattering analyses confirmed that the Cu nanoparticles were uniformly distributed with interparticle distances of 20–35 nm. The Cu-PPFC nanocomposite film with the highest Cu content (80 wt%) exhibited a Raman enhancement factor of 2.18 × 10⁴ for rhodamine 6G, demonstrating its potential as a moderate-sensitivity SERS substrate. Finite-difference time-domain (FDTD) simulations confirmed the strong electromagnetic field localization at the Cu-Cu nanogaps separated by the PPFC matrix, corroborating the experimentally observed SERS enhancement. These results suggest that a Cu-PPFC nanocomposite film, easily fabricated using a composite target, provides an efficient and scalable route for fabricating reproducible, inexpensive, and moderate-sensitivity SERS substrates suitable for practical sensing applications. Full article

Carbon nanotube (CNT) and graphene-reinforced nanocomposites have become exceptional multifunctional materials because of their exceptional mechanical, thermal, and electrical properties. Recent developments in synthesis methods, dispersion strategies, and interfacial engineering have effectively overcome agglomeration-related limitations by significantly improving filler distribution, matrix compatibility, and load-transfer efficiency. These nanocomposites have better wear durability, corrosion resistance, and surface properties like super-hydrophobicity. A comparative analysis of polymer, metal, and ceramic matrices finds benefits for applications in biomedical, construction, energy, defense, and aeronautics. Functionally graded architecture, energy-harvesting nanogenerators, and additive manufacturing are some of the new fabrication processes that enhance design flexibility and functional integration. In recent years, scalability, life-cycle evaluation, and environmentally friendly processing have all gained increased attention. The development of next-generation, high-performance graphene and carbon nanotube (CNT)-based nanocomposites is critically reviewed in this work, along with significant obstacles and potential next steps. Full article

MXenes, a new family of two-dimensional transition-metal carbides and nitrides, have attracted significant interest in biomedicine because of their tunable surface groups and multifunctional properties. Hydrogels, with their three-dimensional polymeric networks rich in water, provide excellent biocompatibility and structural similarity to those of biological tissues. Although synthetic polymer–based MXene hydrogels are well studied, polysaccharide-based systems remain underexplored despite their biodegradability and biomedical relevance. In this work, MXene nanosheets were incorporated into a sodium alginate (ALG)–gellan gum (GG) polymeric blend to develop polysaccharide/MXene hydrogels. Two dehydration approaches, conventional drying and freeze-drying were used to evaluate their influence on the characteristics of the composite, including microstructure, surface roughness, compressive behavior, water states, and thermal stability. Conventionally dried polysaccharide/MXene nanocomposites with 1.0% wt. MXene have reduced the swelling ratio by ~60% and the volume change by 40% compared to polysaccharide blend. Freeze-dried polysaccharide/MXene nanocomposite hydrogels developed a porous, interconnected network, making them promising for applications requiring high surface area, such as adsorption and tissue engineering. In contrast, conventionally dried samples formed compact, smooth structures with improved barrier and mechanical performance. These results demonstrate that the dehydration strategy strongly governs the polymer network architecture, water states, and material functionality, offering pathways to tailor hydrogel modified with MXene for specific biomedical applications. Full article

This study aims to address a major challenge and find solutions for developing less expensive, lighter, and more efficient energy storage materials while remaining environmentally friendly. This work combines the study of the structural, morphological, and optical properties of epoxy nanocomposites containing ZnO and SnO₂ and highlights the influence of oxide filler content on their energy storage performance. To this end, epoxy nanocomposites filled with metal oxides (ZnO and SnO₂) prepared by extrusion, a simple, economical, and reliable industrial method, were studied and compared. The materials obtained are inexpensive, lightweight, and highly efficient, and can replace traditional glass-based systems in the energy sector. The results of XRD, SEM, and FTIR analyses show the absence of impurities, the stability of the structures in humid environments, and the homogeneity of the prepared films. They also indicate that the nature and charge content of the oxide integrated into the polymer matrix play a significant role in the properties of the nanocomposites. Optical measurements were used to determine the film thickness, the type of electronic transition, the band gap energy, and the Urbach energy. Based on the results obtained, the prepared nanocomposite films appear to be promising materials for energy-based optical applications. Full article

There has been tremendous progress in the development and application of nanotechnology in the past ten years. There are a plethora of nanoparticles and nanomaterials that have been developed and used to improve the biosensors’ overall performance. Nanocomposites integrate several nanomaterials inside a matrix to improve their structural and functional characteristics, resulting in enhanced biosensor efficacy. This review covers the achievements in nanocomposites containing metal, polymer, inorganic, carbon-based, or gold nanoparticles as new biosensors for detecting a wide range of (bio)molecules with improved sensitivity, selectivity, and a low limit of detection. The purpose is to give an overview of current advances and applications in the field of nanocomposites utilized in biosensors’ design. Emphasis will be placed on the possible uses of these nanocomposites in biosensing across a range of industries, medication delivery, food safety, healthcare, and environmental monitoring. Full article

In recent years, polymer-based hybrid nanocomposites have emerged as promising alternatives to traditional heavy metal shields due to their low density, flexibility, and environmental safety. In this study, the synthesis of PS-PEG copolymers and the gamma radiation-shielding properties of PS-PEG/As₂O₃, PS-PEG/BN, and PS-PEG/As₂O₃/BN nanocomposites with different compositions are investigated. The goal is to find the optimal nanocomposite composition for gamma radiation shielding and dosimetry. Therefore, the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), effective atomic number, mean free path (MFP), radiation shielding efficiency (RPE), electron density, and specific gamma-ray constant were presented. Gamma rays emitted by the Eu source were detected by a high-purity germanium (HPGe) detector device. GammaVision was used to analyze the given data. Photon energy was in the vicinity of 121.8–1408.0 keV. The MAC values in XCOM simulation tools were used to compute. Gamma-shielding efficiency was increased by an increased number of NPs at a smaller photon energy. At 121.8 keV, the HVL of a composite with 70 wt% As₂O₃ NPs is 2.00 cm, which is comparable to the HVL of lead (0.56 cm) at the same energy level. Due to the increasing need for lightweight, flexible, and lead-free shielding materials, PS-b-PEG copolymer-based nanocomposites reinforced with arsenic oxide and BN NPs will be materials of significant interest for next-generation radiation protection applications. Full article

Silver nanoparticles (AgNPs) are widely used as antibacterial agents either as colloidal solutions or deposited on surfaces. However, the high concentration of AgNPs can lead to cytotoxicity, posing a hazard to healthy cells and tissues. Achieving a balance between antibacterial efficacy and cytocompatibility is crucial for biomedical applications. Polymeric coatings, especially those made from polydimethylsiloxane (PDMS) like Sylgard 184, are popular in biomedical applications due to their user-friendliness. We have developed a cost-effective method to reduce silver ions using the Si-H silane functions of PDMS in situ. Tetrahydrofuran (THF) acts as a solvent, inducing a swelling effect in PDMS, allowing silver ions from silver tetrafluoroborate (AgBF₄) dissolved in THF to diffuse into the polymer and undergo reduction. This process results in PDMS functionalized with well-distributed 10 nm silver AgNPs. The resulting metal–polymer nanocomposites (MPNs) exhibit yellow shades and, based on qualitative Live/Dead staining observations, show no apparent cytotoxicity on human gingival fibroblasts. In addition, SEM analyses indicate a qualitative reduction in E. coli adhesion, suggesting an antibacterial anti-adhesive potential against this bacterial strain. Further studies should investigate the release profile of AgNPs in these composites, which could guide the development of new biocompatible coatings for phototherapy devices and enhance their long-term clinical performance. Full article

Fiber-reinforced polymer composites, particularly carbon fiber and glass fiber reinforced composites, are widely used in cutting-edge industries due to their excellent properties, such as light weight and high strength. This review systematically compares and summarizes recent research advances in flame retardancy for carbon fiber-reinforced polymers and glass fiber-reinforced polymers. Focusing on various polymer matrices, including epoxy, polyamide, and polyetheretherketone, the mechanisms and synergistic effects of different flame-retardant modification strategies—such as additive flame retardants, nanocomposites, coating techniques, intrinsically flame-retardant polymers, and advanced manufacturing processes—are analyzed with emphasis on improving flame retardancy and suppressing the “wick effect.” The review critically examines the challenges in balancing flame retardancy, mechanical performance, and environmental friendliness in current approaches, highlighting the key role of interface engineering in mitigating the “wick effect.” Based on this analysis, four future research directions are proposed: implementing green design principles throughout the material life cycle; promoting the use of natural fibers, bio-based resins, and bio-derived flame retardants; developing intelligent responsive flame-retardant systems based on materials such as metal–organic frameworks; advancing interface engineering through biomimetic design and advanced characterization to fundamentally suppress the fiber “wick effect”; and incorporating materials genome and high-throughput preparation technologies to accelerate the development of high-performance flame-retardant composites. This review aims to provide systematic theoretical insights and clear technical pathways for developing the next generation of high-performance, safe, and sustainable fiber-reinforced composites. Full article

The market for bioactive compounds of natural origin has expanded greatly over the past few years. These compounds can be found as individual supplements or food additives. Due to the importance of this market, incorrect data on their composition can often be found. Therefore, monitoring their concentration is of great importance. Although there are various methods for their selective and sensitive determination, electrochemical sensors represent an important tool in this field. With the development of nanotechnology, additional importance has been given to these sensors. Strictly controlled synthesis procedures can yield nanomaterials with unique morphological properties and significantly improved electrocatalytic capabilities. The integration of two or more nanomaterials in the form of a nanocomposite and/or nanohybrids allows for the synergistic effect of each of the components. Thus, excellent final characteristics are obtained in the field of electrochemical sensors, such as improved sensor stability, selectivity, and lower detection limits. In recent years, various forms of carbon nanomaterials, polymer films, metal and metal oxide nanoparticles (or simply metal/metal oxide nanoparticles), MOFs, porous nanomaterials, MXenes, and others with clearly defined characteristics represent an important step forward in this field. Carefully prepared, these materials achieve strong interactions with selected analytes, which results in significant progress in analytical methods for monitoring biologically active compounds. Therefore, this review summarizes the latest trends in this field, focusing on the method of material preparation, final morphology and electrocatalytic properties, selectivity, and sensitivity. Conclusions and expected future directions in this field are also given in order to improve current analytical performance. Full article

Type IV composite overwrapped pressure vessels—characterized by a polymer liner fully wrapped in fiber-reinforced polymer—are emerging as lightweight, corrosion-proof alternatives to traditional metal cylinders in fire safety applications. This paper presents a comprehensive review of Type IV high-pressure vessels used in portable fire extinguishers and self-contained breathing apparatus (SCBA) systems. We outline recent material innovations for both the non-metallic liners and composite shells, including multilayer liner designs (e.g., high-barrier polymers and nanocomposites) and advanced fiber/resin systems. Key manufacturing developments such as automated filament winding, resin infusion, and in-line non-destructive testing are discussed. Technical performance in fire applications is critically examined: current standards and certification requirements (EU and international), typical design pressures (e.g., 300 bar in SCBA) and safety factors, common failure modes (liner collapse, fiber rupture, etc.), inspection protocols, and a comparison with Type IV hydrogen storage cylinders. Market trends are also reviewed, highlighting the major manufacturers and the growing adoption of composite extinguishers (e.g., 20-year service-life composite units) versus conventional steel. The review draws on 7–10 peer-reviewed studies to analyze the state of the art, finding that Type IV vessels offer significant weight reduction (>30%) and corrosion resistance at the cost of more complex design and certification. In firefighting use, these cylinders demonstrably improve firefighter mobility and reduce maintenance, while meeting rigorous safety standards. Remaining challenges include further improving liner permeability barriers to prevent gas leakage or collapse, understanding long-term composite aging under cyclic loads, and optimizing fire resistance. Overall, Type IV composite pressure vessels represent a major innovation in fire suppression technology, enabling safer and more efficient extinguishing equipment. Future research and standardization efforts are recommended to fully realize their benefits in fire protection. Full article

The integration of polymer coatings with metal and metal oxide nanoparticles represents a significant advancement in nanotechnology, enhancing the stability, biocompatibility, and functional versatility of these materials. These enhanced properties make polymer-coated nanoparticles key components in a wide range of applications, including biomedicine, catalysis, environmental remediation, electronics, and energy storage. The unique combination of polymeric materials with metal and metal oxide cores results in hybrid structures with superior performance characteristics, making them highly desirable for various technological innovations. Polymer-coated metal and metal oxide nanoparticles can be synthesized through various methods, such as grafting to, grafting from, grafting through, in situ techniques, and layer-by-layer assembly, each offering distinct control over nanoparticle size, shape, and surface functionality. The distinctive contribution of this review lies in its systematic comparison of polymer-coating synthesis approaches for different metal and metal oxide nanoparticles, revealing how variations in polymer architecture and surface chemistry govern their stability, functionality, and application performance. The aim of this paper is to provide a comprehensive overview of the current state of research on polymer-coated nanoparticles, including metals such as gold, silver, copper, platinum, and palladium, as well as metal oxides like iron oxide, titanium dioxide, zinc oxide, and aluminum oxide. This review highlights their design strategies, synthesis methods, characterization approaches, and diverse emerging applications, including biomedicine (e.g., targeted drug delivery, gene delivery, bone tissue regeneration, imaging, antimicrobials, and therapeutic interventions), environmental remediation (e.g., antibacterials and sensors), catalysis, electronics, and energy conversion. Full article

In response to the urgent need for sustainable antibacterial solutions against antibiotic-resistant pathogens, this study presents a facile dendritic polymer-assisted approach for synthesizing highly active ZnO/mesoporous silica nanocomposites (SBA-15, SBA-16, KIT-6, MSU-X). Two hyperbranched polymers—polyethyleneimine (PEI) and carboxy-methylated polyethyleneimine (Trilon-P, TrP)—were employed as templating and metal-trapping agents. The influence of pore geometry, polymer functionality, and polymer-loading method (wet or dry impregnation) on ZnO nanoparticle (NP) formation was systematically examined. All nanocomposites exhibited high structural homogeneity, incorporating ultrasmall or amorphous ZnO NPs (1–10 nm) even at 8 wt.% Zn loading. Zn uptake was strongly dependent on polymer end groups, while the spatial distribution of ZnO NPs was dictated by the silica host structure. Antibacterial assays against Staphylococcus aureus revealed remarkable activity, particularly for ZnO/SBA-15_PEI, ZnO/SBA-16_PEI, and ZnO/MSU-X_TrP nanocomposites, with minimum inhibitory concentrations of 1–2.5 μg mL⁻¹ Zn and over 90% mammalian cell viability. Life Cycle Assessment identified energy use as the main environmental factor, with ZnO/SBA-15_PEI_WI displaying the lowest impact. Overall, the interplay between silica pore architecture, polymer type, and impregnation method governs ZnO accessibility and bioactivity, establishing a versatile strategy for designing next-generation ZnO/SiO₂ nanocomposites with tunable antibacterial efficacy and minimal cytotoxic and environmental footprint. Full article

A comprehensive investigation was conducted focusing on two series of poly(lactic acid) (PLA)-based nanocomposites filled with small amounts (0.5 and 1.0%) of metal (Ag/Cu) nanoparticles (NPs). Our work aimed to synthesize PLA/Ag nanocomposites via in situ ring-opening polymerization (ROP), and for comparison purposes, the same materials were also prepared via solution casting followed by melt mixing. PLA/Cu nanocomposites were also prepared via melt extrusion. Gel permeation chromatography (GPC) and intrinsic viscosity measurements [η] showed that the incorporation of Ag nanoparticles (AgNPs) resulted in a decrease in the molecular weight of the PLA matrix, indicating a direct effect of the AgNPs on its macromolecular structure. Fourier-transform infrared spectroscopy (FTIR) revealed no significant changes in the characteristic peaks of the nanocomposites, except for an in situ sample containing 1.0 wt% of AgNPs, where slight interactions in the C=O region were detected. Differential scanning calorimetry (DSC) analysis confirmed the semi-crystalline nature of the materials. Glass transition temperature was strongly affected by the presence of NPs in the case of the in situ-based samples. Melt crystallized studies suggested potential indirect polymer–NP interactions, while isothermal melt crystallization experiments confirmed the nucleation ability of the NPs. The mechanical performance was assessed via tensile and flexural measurements, revealing that the in situ-based samples exhibited remarkable flexibility. Moreover, during the three-point bending tests, none of the in situ nanocomposite samples broke. In this context, next-generation PLA-based nanocomposites have been proposed for advanced applications, including flexible printed electronics. Full article

 This review comprehensively examines nanocomposite packaging materials for food preservation, focusing on their preparation methods, functional properties, applications, and safety considerations. Nanocomposites, incorporating nanomaterials such as metal nanoparticles, polysaccharides, or essential oils into polymer matrices, demonstrate enhanced mechanical strength, barrier properties (e.g., reduced water vapor and oxygen permeability), and significant antimicrobial activity. These advancements address critical food spoilage challenges by extending shelf life and maintaining quality in diverse products like fruits, vegetables, meats, and dairy. In addition, this review highlights concerns regarding potential cytotoxicity and migration of nanoparticles, underscoring the need for rigorous safety evaluations. While current methods (e.g., ionic gelation, electrospinning) show promise, scalability remains limited. Future research should prioritize eco-friendly designs, functional integration, and standardized safety protocols to facilitate commercial adoption.  Full article