Search Results (344)

Thin-film composite nanofiltration membranes were fabricated via the interfacial polymerization method from optimized polyethersulfone (PES) mixed matrix membranes, using m-phenylenediamine and trimesoyl chloride monomers, which produced a selective polyamide layer and were used for heavy metal removal. The concentration of trimesoyl chloride (TMC) is a critical factor to govern the properties of the selective polyamide layer, which directly influences the surface morphology and selective performance of (0.5 wt%) PES-coreshell-Fe₃O₄/ZnO membranes. Morphological structure, illustrated by SEM images, elucidated the role of TMC addition. FTIR spectra validated the successful formation of the amine and acyl chloride groups. Performance studies illustrated that NF3 (made from 0.1 w/v% of TMC) showed a unique salt rejection trend (NaCl > Na₂SO₄ > MgCl₂) with an optimal salt rejection of 52.64%, 50.91%, and 12.67%. A low concentration of 0.1 w/v% of the NF3 membrane was the most optimal high-performance membrane. The adsorption rate of NF3 for Pb(II) ions in real environmental wastewater is attributed to the tailored surface chemistry of the polyamide layered thin-film/PES-coreshell-Fe₃O₄/ZnO nanocomposites of the membranes. The maximum Langmuir adsorption capacity at the optimal pH = 5 was 8.8573 mg/g at 25 °C. The fabricated adsorptive nanofiltration membranes alleviated the presence of Pb(II) ions and other competing ions present in environmental wastewater. 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 study compares the structural, morphological, magnetic, and photocatalytic properties of a pure SiO₂ matrix, a ZnFe₂O₄-doped SiO₂ nanocomposite (both synthesized via the sol-gel method), and bulk ZnFe₂O₄ produced by thermal decomposition. Thermogravimetric analysis (TGA) reveals that metal oxalates form below 200 °C and decompose into metal oxides, which subsequently form ferrite. Fourier-transform infrared (FTIR) spectroscopy confirms the embedding of both undoped and ZnFe₂O₄-doped nanoparticles into the SiO₂ matrix at all investigated annealing temperatures. X-ray diffraction (XRD) consistently reveals the formation of crystalline ZnFe₂O₄, with the crystallite size increasing from 48 to 93 nm upon annealing. Atomic force microscopy (AFM) shows spherical ferrite nanoparticles surrounded by an amorphous layer, with particle growth observed at higher temperatures. Structural parameters derived from XRD (e.g., crystallite size, density, porosity, lattice constant, unit cell volume) and AFM (e.g., particle size, coating thickness) as well as magnetic parameters (saturation magnetization, remanence, anisotropy, coercivity) demonstrate clear dependence on both dopant presence and annealing temperature. Magnetic measurements reveal enhanced properties with increasing ferrite content and heat treatment, with a transition from superparamagnetic behavior at 700 °C to ferrimagnetic behavior above 1000 °C. Scavenger experiments confirmed the involvement of holes, hydroxyl radicals, and superoxide radicals in the photocatalytic process. The photocatalytic efficiency, as evaluated by the Rhodamine B degradation under visible light, highlights the promising potential of the obtained nanocomposite for advanced environmental and technological applications. Full article

Periodontitis is a chronic oral inflammatory disease whose treatment is often hindered by poor drug retention, prolonged therapeutic regimens, and the rise of antibiotic resistance. In this study, we developed a Hydrogel@ZIF-8@metronidazole (Hydrogel@ZIF-8@MNZ) nanocomposite dressing for targeted, sustained, and in situ antimicrobial therapy. This system integrates ZIF-8, a pH-responsive metal–organic framework, with the antimicrobial agent metronidazole (MNZ), encapsulated within a crosslinked hydrogel matrix to enhance stability and retention in the oral environment. Drug release studies demonstrated that MNZ release was significantly accelerated under acidic conditions (pH 5.0), mimicking the periodontal microenvironment. The Hydrogel@ZIF-8 composite achieved a maximum MNZ adsorption capacity of 132.45 mg·g⁻¹, with a spontaneous and exothermic uptake process best described by a pseudo-second-order kinetic model, suggesting chemisorption as the dominant mechanism. The nanoplatform exhibited strong pH-responsive behavior, with enhanced drug release under acidic conditions and potent dose-dependent bactericidal activity against Fusobacterium nucleatum (Fn). At the highest tested concentration, bacterial survival was reduced to approximately 30%, with extensive membrane disruption observed through live/dead fluorescence microscopy. In summary, the stimuli-responsive Hydrogel@ZIF-8@MNZ nanocomposite offers an intelligent and effective therapeutic strategy for periodontitis. By tailoring its action to the disease microenvironment, this platform enables sustained and localized antibacterial therapy, addressing major challenges in the treatment of chronic oral infections. Full article

Nanobiocomposites are a class of biomaterials that include at least one phase with constituents in the nanometer range. Nanobiocomposites, a new class of materials formed by combining natural and inorganic materials (metals, ceramics, polymers, and graphene) at the nanoscale dimension, are expected to revolutionize tissue engineering and bone implant applications because of their enhanced corrosion resistance, mechanical properties, biocompatibility, and antimicrobial activity. Titanium-based nanocomposites are gaining attention in biomedical applications due to their exceptional biocompatibility, corrosion resistance, and mechanical properties. These composites typically consist of a titanium or titanium alloy matrix that is embedded with nanoscale bioactive phases, such as hydroxyapatite, bioactive glass, polymers, or carbon-based nanomaterials. Common methods for synthesizing Ti-based nanobiocomposites and their parts, including bottom-up and top-down approaches, are presented and discussed. The synthesis conditions and appropriate functionalization influence the final properties of nanobiomaterials. By modifying the surface roughness at the nanoscale level, composite implants can be enhanced to improve tissue integration, leading to increased cell adhesion and protein adsorption. The objective of this review is to illustrate the most recent research on the synthesis and properties of Ti-based biocomposites and their scaffolds. Full article

Aluminium metal matrix composites (AMMCs) incorporate aluminium alloys reinforced with fibres (continuous/discontinuous), whiskers, or particulate. These materials were engineered as advanced solutions for demanding sectors including construction, aerospace, automotive, and marine. Micro- and nano-scale reinforcing particles typically enable attainment of exceptional combined properties, including reduced density with ultra-high strength, enhanced fatigue strength, superior creep resistance, high specific strength, and specific stiffness. Microstructural, mechanical, and tribological characterizations were performed, evaluating input parameters like reinforcement weight percentage, applied normal load, sliding speed, and sliding distance. Fabricated nanocomposites underwent tribometer testing to quantify abrasive and erosive wear behaviour. Multiple investigations employed the Taguchi technique with regression modelling. Analysis of variance (ANOVA) assessed the influence of varied test constraints. Applied load constituted the most significant factor affecting the physical/statistical attributes of nanocomposites. Sliding velocity critically governed the coefficient of friction (COF), becoming highly significant for minimizing COF and wear loss. In this review, the reinforcement homogeneity, fractural behaviour, and worn surface morphology of AMMCswere examined. Full article

Polymer matrix composites (PMCs) are crucial for their applications in aerospace, electronics, defense, and structural materials. PMCs reinforced with nanofillers offer substantial potential for enhanced thermal and mechanical performance. Although there have been significant developments in nanofiller-based high-performance composites involving graphene, carbon nanotubes, and metal oxides, the smallest of all the fillers, the graphene quantum dot (GQD), has not been explored thoroughly. The objective of this study is to investigate the effects of GQDs on the thermal properties of epoxy nanocomposites using all-atom molecular dynamics (MD) simulations. Specifically, the influence of GQDs on the glass transition temperature (T_g) and coefficient of linear thermal expansion (CTE) of the bisphenol F epoxy is evaluated. Further, the effects of surface functionalization and edge functionalization of GQDs are analyzed. Results demonstrate that the inclusion of functionalized GQDs leads to a 16% improvement in T_g, attributed to enhanced interfacial interactions and restricted molecular mobility in the epoxy network. MD simulations reveal that functional groups on GQDs form strong physical and chemical interactions with the polymer matrix, effectively altering its dynamics at the T_g. These results provide key molecular-level insights into the design of the next generation of thermally stable epoxy nanocomposites for high-performance applications in aerospace and defense. Full article

Conductive composites are a flexible class of engineered materials that combine conductive fillers with an insulating matrix—usually made of ceramic, polymeric, or a hybrid material—to customize a system’s electrical performance. By providing tunable electrical properties in addition to benefits like low density, mechanical flexibility, and processability, these materials are intended to fill the gap between conventional insulators and conductors. The increasing need for advanced technologies, such as energy storage devices, sensors, flexible electronics, and biomedical interfaces, has significantly accelerated their development. The electrical characteristics of composite materials, including metallic, ceramic, polymeric, and nanostructured systems, are thoroughly examined in this review. The impact of various reinforcement phases—such as ceramic fillers, carbon-based nanomaterials, and metallic nanoparticles—on the electrical conductivity and dielectric behavior of composites is highlighted. In addition to conduction models like correlated barrier hopping and Debye relaxation, the study investigates mechanisms like percolation thresholds, interfacial polarization, and electron/hole mobility. Because of the creation of conductive pathways and improved charge transport, developments in nanocomposite engineering, especially with regard to graphene derivatives and silver nanoparticles, have shown notable improvements in electrical performance. This work covers the theoretical underpinnings and physical principles of conductivity and permittivity in composites, as well as experimental approaches, characterization methods (such as SEM, AFM, and impedance spectroscopy), and real-world applications in fields like biomedical devices, sensors, energy storage, and electronics. This review provides important insights for researchers who want to create and modify multifunctional composite materials with improved electrical properties by bridging basic theory with technological applications. Full article

Chitosan is a natural biopolymer with intrinsic antimicrobial properties and strong metal ion chelating properties, making it an ideal matrix for the development of bioactive composites. In this study, silver and copper nanoparticles were synthesized using laser ablation in liquid (LAL) by the ablation of metallic targets into commercial chitosan (Cs) and chitosan produced from Hermetia illucens pupal exuviae (CsE) solutions, avoiding the use of chemical precursors or stabilizing agents. The nanocomposites obtained were characterized by UV–vis spectroscopy, TEM microscopy and FTIR spectroscopy in order to evaluate the size of the nanoparticles and the interactions between the polymer and metal nanoparticles. Antibacterial tests demonstrated the efficacy of Ag-based composites with a minimum inhibitory concentration (MIC) of 0.006 g/L, and Cu-based composites with a MIC of 0.003 g/L against both Escherichia coli and Micrococcus flavus. While the silver composites show antibacterial activity in both colloidal and film forms, the copper composites present antibacterial activity only in colloidal form. Swelling tests indicated that all films maintained a high water absorption capacity, with a swelling index over 200%, unaffected by nanoparticle integration. The results highlight the potential of LAL-synthesized metal–chitosan composites, particularly those based on insect chitosan, as sustainable and effective antimicrobial materials for biomedical and environmental applications. Full article

A facile and versatile strategy to obtain NPs@ZnAlO nanocomposite materials, comprising controlled-size nanoparticles (NPs) within a ZnAlO matrix is reported. The mono-(Au, Ni) and bimetallic (Ni-Au) NPs serving as an active phase were prepared by the polyol-alkaline method, while the ZnAlO support was obtained via the thermal decomposition of its corresponding layered double hydroxide (LDH) precursors. X-ray diffraction (XRD) patterns confirmed the successful fabrication of the nanocomposites, including the synthesis of the metallic NPs, the formation of LDH-like structure, and the subsequent transformation to ZnO phase upon LDH calcination. The obtained nanostructures confirmed the nanoplate-like morphology inherited from the original LDH precursors, which tended to aggregate after the addition of gold NPs. According to the UV-Vis spectroscopy, loading NPs onto the ZnAlO support enhanced the light absorption and reduced the band gap energy. ATR-DRIFT spectroscopy, H₂-TPR measurements, and XPS analysis provided information about the functional groups, surface composition, and reducibility of the materials. The catalytic performance of the developed nanostructures was evaluated by the photodegradation of bisphenol A (BPA), under simulated solar irradiation. The conversion of BPA over the bimetallic Ni-Au@ZnAlO reached up to 95% after 180 min of irradiation, exceeding the monometallic Ni@ZnAlO and Au@ZnAlO catalysts. Its enhanced activity was correlated with good dispersion of the bimetals, narrower band gap, and efficient charge carrier separation of the photo-induced e⁻/h⁺ pairs. Full article

Nano-titanium dioxide ceramic coatings exhibit excellent wear resistance, corrosion resistance, and self-cleaning properties, showing great potential as multifunctional protective materials. This study proposes a synergistic reinforcement strategy by encapsulating micron-sized Al₂O₃ particles with nano-TiO₂. A core-shell structured nanocomposite coating composed of 65 wt% nano-TiO₂ encapsulating 30 wt% micron-Al₂O₃ was precisely designed and fabricated via a slurry dip-coating method on Q235 steel substrates. The microstructure and surface morphology of the coatings were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Comprehensive performance evaluations including densification, adhesion strength, wear resistance, and thermal shock resistance were conducted. Optimal coating properties were achieved under the conditions of a binder-to-solvent ratio of 1:15 (g/mL), a heating rate of 2 °C/min, and a sintering temperature of 400 °C. XRD analysis confirmed the formation of multiple crystalline phases during the 400 °C curing process, including titanium pyrophosphate (TiP₂O₇), aluminum phosphate (AlPO₄), copper aluminate (Cu(AlO₂)₂), and a unique titanium phosphate phase (Ti₃(PO₄)₄) exclusive to the 2 °C/min heating rate. Adhesion strength tests revealed that the coating sintered at 2 °C/min exhibited superior interfacial bonding strength and outstanding performance in wear resistance, hardness, and thermal shock resistance. The incorporation of nano-TiO₂ into the 30 wt% Al₂O₃ matrix significantly enhanced the mechanical properties of the composite coating. Mechanistic studies indicated that the bonding between the nanocomposite coating and the metal substrate is primarily achieved through mechanical interlocking, forming a robust physical interface. These findings provide theoretical guidance for optimizing the fabrication process of metal-based ceramic coatings and expanding their engineering applications in various industries. Full article

The aim of this study is to explore the feasibility of using flotation wastewater from copper–porphyry ore processing to synthesize a gel that serves as a precursor for a polymer nanocomposite used in supercapacitor electrode fabrication. These wastewaters—characterized by high acidity and elevated concentrations of metal cations (Cu, Ni, Zn, Fe), sulfates, and organic reagents such as xanthates, oil (20 g/t ore), flotation frother (methyl isobutyl carbinol), and pyrite depressant (CaO, 500–1000 g/t), along with residues from molybdenum flotation (sulfuric acid, sodium hydrosulfide, and kerosene)—are byproducts of copper–porphyry gold-bearing ore beneficiation. The reduction of Ni powder in the wastewater induces the degradation and formation of a gel that captures both residual metal ions and organic compounds—particularly xanthates—which play a crucial role in the subsequent steps. The resulting gel is incorporated during the oxidative polymerization of aniline, forming a nanocomposite with a polyaniline matrix and embedded xanthate-based compounds. An asymmetric supercapacitor was assembled using the synthesized material as the cathodic electrode. Electrochemical tests revealed remarkable capacitance and cycling stability, demonstrating the potential of this novel approach both for the valorization of industrial waste streams and for enhancing the performance of energy storage devices. Full article

In this review work, the different routes and methods for preparing hybrid materials based on nanostructured block copolymers (BCPs) and magnetic nanoparticles (MNPs) are analyzed, as they can be potentially employed in different sectors like biomedicine, electronic or optoelectronic devices, data storing devices, etc. The first procedure for their preparation consists of the nanostructuring of BCPs in the presence of previously synthesized NPs by modifying their surface for increasing compatibility with the matrix or employing magnetic fields for NP orientation, which can also promote the orientation of nanodomains. Surface modification with surfactants led to the selective confinement of NPs depending on the interaction (mainly hydrogen bonding) degree and their intensity. Surface modification with brushes can be performed by three methods, including grafting from, grafting to, or grafting through. Those methods are compared in terms of success for the positioning and confinement of NPs in the desired domains, showing the crucial importance of brush length and grafting density, as well as of NP amount and modification degree in the self-assembled morphology. Regarding the use of external magnetic fields, the importance of relative amounts of MNPs and BCPs employed and that of the magnetic field intensity for the orientation of the NPs and the nearby BCP domains is shown. The second procedure, consisting of the in situ synthesis of NPs inside the nanodomains by a reduction in the respective metallic ions or employing metal-containing BCPs for the generation of MNP patterns or arrays, is also shown. In all cases, the transference of magnetic properties to the nanocomposite was successful. Finally, a brief summary of some aspects about the use of BCPs for the synthesis, encapsulation, and release of MNPs is shown, as they present potential biomedical applications such as cancer treatment, among others. Full article

SiAlCN coatings were first obtained by the method of reactive evaporation of aluminum and plasma chemical activation of an organosilicon precursor in a hollow cathode arc discharge. The spectrum of discharge plasma was studied by optical emission spectroscopy under conditions of evaporation of Al in an Ar+N₂+hexamethyldisilazane vapor/gas medium, and it was shown that in the presence of a metal component in the plasma, not only did intensive activation of various components of the media occur but also an increased ionic effect on the surface of the coating was provided, with a deposition rate of up to 10.1 µm/h. The films had a dense and homogeneous structure and had a hardness of up to 31 GPa and good adhesion on stainless steel. The results of SEM, FTIR, and XRD showed that their structure was a nanocomposite consisting of an amorphous matrix based on SiCN and AlN with inclusions of AlCN nanocrystals. Full article

Doping undermines fairness in sports and threatens athlete health, while conventional detection methods like LC-MS and GC-MS face challenges such as complex procedures, matrix interferences, and lengthy processing times, limiting on-site applications. Two-dimensional (2D) materials, including graphene, MoS₂, and metal–organic frameworks (MOFs), offer promising solutions due to their large surface areas, tunable electronic structures, and special interactions with doping agents, such as hydrogen bonding, π-π stacking, and electrostatic forces. These materials enable signal transduction through changes in conductivity or fluorescence quenching. This review highlights the use of 2D materials in doping detection. For example, reduced graphene oxide–MOF composites show high sensitivity for detecting anabolic steroids like testosterone, while NiO/NGO nanocomposites exhibit strong selectivity for stimulants like ephedrine. However, challenges such as environmental instability and high production costs hinder their widespread application. Future efforts should focus on improving material stability through chemical modifications, reducing production costs, and integrating these materials into advanced systems like machine learning. Such advancements could revolutionize doping detection, ensuring fairness in sports and protecting athlete health. Full article