Search Results (9,266)

Effluent-containing dye molecules is a significant environmental hazard. An economical and energy-saving solution is needed to combat this issue for the purpose of environmental sustainability. In this study, Fe-Ni-Co-based trimetallic nanocomposite was synthesized using the coprecipitation method. Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infra-Red spectroscopy were conducted to explore the physical morphology, phase structure and functional groups of the synthesized catalyst. Among dyes, methyl orange is considered as a major contaminant in textile effluent. The current study focused on the degradation of methyl orange using a trimetallic Fe-Ni-Co-based nanocomposite. A central composite design in response surface methodology was employed to analyze the independent variables including dye concentration, catalyst dose, temperature, hydrogen peroxide, irradiation time, and pH. Dye degradation has been achieved up to 81% in 20 min at the lowest initial concentration (5 mg/L) in optimized conditions. Based on ANOVA, the predicted values were in great agreement with the actual values, signifying the applicability of response surface methodology in the photocatalytic decolorization of dyeing effluents. The results gained from this research demonstrated that the synthesis method of trimetallic nanocomposite (Iron Triad) is a cost-effective and energy efficient method that can be scaled up to a higher level for industrial application. Full article

A set of Pd-containing composites was prepared by the deposition of Pd on the following carriers: polyaniline (PANI); PANI doped by H₂SO₄; Norit GSX activated carbon or Aerosil (SiO₂) coated by PANI or by H₂SO₄-doped PANI; PANI after thermal treatment at 300 °C in an atmosphere of H₂. One sample was also prepared by the in situ polymerization of aniline in the presence of Pd²⁺· The decomposition of Pd was carried out via deposition from the solutions of Pd²⁺ salts or decomposition of Pd⁰ complex Pd₂(dba)₃, where dba is dibenzylideneacetone. The composites were studied by powder X-ray diffraction, transmission electron microscopy, IR and Raman spectroscopy. The hydrogenation of quinoline in the presence of composites was carried out; the catalytic performance of the composites was evaluated by the yield of 1,2,3,4-tetrahydroquinoline. It was found that the doping of PANI by H₂SO₄, inclusion of Norit GSX activated carbon as a component of the carrier or thermal treatment of PANI prior to the deposition of Pd led to significant increase in the catalytic performance of the composites in the hydrogenation of quinoline. Full article

Nanocomposites with a natural rubber (NR) matrix containing organomodified montmorillonite (MMT) as a precursor of nanoparticles were prepared using two different polyoxazolines as surface modifiers of the MMT. The materials were characterized by X-ray diffraction, transmission electronic microscopy and ultimate mechanical properties, and parameters obtained by DMTA method (storage and loss moduli and loss tangent) were determined. It was found that the effect of nanofillers presence has a significant effect on tensile strength as well as elongation at break, which are higher for materials with higher viscosity due to the presence of carbon blacks compared to the composites without carbon blacks. From the two modifiers, poly(2-ethyl-2-oxazoline) was identified as a prospective modifier for surface modification of MMT used as the possible additive for tyre treads exhibiting optimal balance between fuel consumption and safety of driving concerning breaking action and lateral breakaway. Full article

Currently, there is an increasing need to find new ways to purify water by eliminating bacterial biofilms, textile dyes, and toxic water pollutants. These contaminants pose significant risks to both human health and the environment. To address this issue, in this study, we have developed an eco-friendly approach that involves synthesizing a cobalt-doped cerium iron oxide (CCIO) nanocomposite (NC) using an aqueous extract of Gossypium arboreum L. stalks. The resulting nanoparticles can be used to effectively purify water and tackle the challenges associated with these harmful pollutants. Nanoparticles excel in water pollutant removal by providing a high surface area for efficient adsorption, versatile design for the simultaneous removal of multiple contaminants, catalytic properties for organic pollutant degradation, and magnetic features for easy separation, offering cost-effective and sustainable water treatment solutions. A CCIO nanocomposite was synthesized via a green co-precipitation method utilizing biomolecules and co-enzymes extracted from the aqueous solution of Gossypium arboreum L. stalk. This single-step synthesis process was accomplished within a 5-h reaction period. Furthermore, the synthesis of nanocomposites was confirmed by various characterization techniques such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and energy dispersive X-ray (EDX) technology. CCIO NCs were discovered to have a spherical shape and an average size of 40 nm. Based on DLS zeta potential analysis, CCIO NCs were found to be anionic. CCIO NCs also showed significant antimicrobial and antioxidant activity. Overall, considering their physical and chemical properties, the application of CCIO NCs for the adsorption of various dyes (~91%) and water pollutants (chromium = ~60%) has been considered here since they exhibit great adsorption capacity owing to their microporous structure, and represent a step forward in water purification. Full article

Polylactide materials present a promising alternative to petroleum-based polymers due to their sustainability and biodegradability, although they have certain limitations in physical and mechanical properties for specific applications. The incorporation of nanoparticles, such as layered silicate (clay), carbon nanotubes, metal or metal oxide, cellulose nanowhiskers, can address these limitations by enhancing the thermal, mechanicals, barriers, and some other properties of polylactide. However, the distinct characteristics of these nanoparticles can affect the compatibility and processing of polylactide blends. In the polylactide nanocomposites, well-dispersed nanoparticles within the polylactide matrix result in excellent mechanical and thermal properties of the materials. Surface modification is required to improve compatibility and the crystallization process in the blended materials. This article reviews the development of polylactide nanocomposites and their applications. It discusses the general aspect of polylactides and nanomaterials as nanofillers, followed by the discussion of the processing and characterization of polylactide nanocomposites, including their applications. The final section summarizes and discusses the future challenges of polylactide nanocomposites concerning the future material’s requirements and economic considerations. As eco-friendly materials, polylactide nanocomposites offer significant potential to replace petroleum-based polymers. Full article

Exfoliated graphite (ExG) embedded in a polymeric matrix represents an accessible, cost-effective, and sustainable method for generating nanosized graphite-based polymer composites with multifunctional properties. This review article analyzes diverse methods currently used to exfoliate graphite into graphite nanoplatelets, few-layer graphene, and polymer-assisted graphene. It also explores engineered methods for small-scale pilot production of polymer nanocomposites. It highlights the chemistry involved during the graphite intercalation and exfoliation process, particularly emphasizing the interfacial interactions related to steric repulsion forces, van der Waals forces, hydrogen bonds, π-π stacking, and covalent bonds. These interactions promote the dispersion and stabilization of the graphite derivative structures in polymeric matrices. Finally, it compares the enhanced properties of nanocomposites, such as increased thermal and electrical conductivity and electromagnetic interference (EMI) shielding applications, with those of neat polymer materials. Full article

Shale formations present significant challenges to traditional drilling fluids due to fluid infiltration, cuttings dispersion, and shale swelling, which can destabilize the wellbore. While oil-based drilling fluids (OBM) effectively address these concerns about their environmental impact, their cost limits their widespread use. Recently, nanomaterials (NPs) have emerged as a promising approach in drilling fluid technology, offering an innovative solution to improve the efficiency of water-based drilling fluids (WBDFs) in shale operations. This study evaluates the potential of utilizing modified silica nanocomposite and graphene nanopowder to formulate a nanoparticle-enhanced water-based drilling fluid (NP-WBDF). The main objective is to investigate the impact of these nanoparticle additives on the flow characteristics, filtration efficiency, and inhibition properties of the NP-WBDF. In this research, a silica nanocomposite was successfully synthesized using emulsion polymerization and analyzed using FTIR, PSD, and TEM techniques. Results showed that the silica nanocomposite exhibited a unimodal particle size distribution ranging from 38 nm to 164 nm, with an average particle size of approximately 72 nm. Shale samples before and after interaction with the graphene nanopowder WBDF and the silica nanocomposite WBDF were analyzed using scanning electron microscopy (SEM). The NP-WBM underwent evaluation through API filtration tests (LTLP), high-temperature/high-pressure (HTHP) filtration tests, and rheological measurements conducted with a conventional viscometer. Experimental results showed that the silica nanocomposite and the graphene nanopowder effectively bridged and sealed shale pore throats, demonstrating superior inhibition performance compared to conventional WBDF. Post adsorption, the shale surface exhibited increased hydrophobicity, contributing to enhanced stability. Overall, the silica nanocomposite and the graphene nanopowder positively impacted rheological performance and provided favorable filtration control in water-based drilling fluids. Full article

In the present study, composites incorporating NiO-Co₃O₄ (NC) and CuO-NiO-Co₃O₄ (CNC) as active electrode materials were produced through the hydrothermal method and their performance was investigated systematically. The composition, formation, and nanocomposite structure of the fabricated material were characterized by XRD, FTIR, and UV–Vis. The FE-SEM analysis revealed the presence of rod and spherical mixed morphologies. The prepared NC and CNC samples were utilized as supercapacitor electrodes, demonstrating specific capacitances of 262 Fg⁻¹ at a current density of 1 Ag⁻¹. Interestingly, the CNC composite displayed a notable long-term cyclic stability 84.9%, which was observed even after 5000 charge–discharge cycles. The exceptional electrochemical properties observed can be accredited to the harmonious effects of copper oxide addition, the hollow structure, and various metal oxides. This approach holds promise for the development of supercapacitor electrodes. These findings collectively indicate that the hydrothermally synthesized NC and CNC nanocomposites exhibit potential as high-performance electrodes for supercapacitor applications. Full article

A ZnO-Graphene oxide nanocomposite (Z-G) was prepared in order to exploit the biomedical features of each component in a single anticancer material. This was achieved by means of an environmentally friendly synthesis, taking place at a low temperature and without the involvement of toxic reagents. The product was physicochemically characterized. The ZnO-to-GO ratio was determined through thermogravimetric analysis, while scanning electron microscopy and transmission electron microscopy were used to provide insight into the morphology of the nanocomposite. Using energy-dispersive X-ray spectroscopy, it was possible to confirm that the graphene flakes were homogeneously coated with ZnO. The crystallite size of the ZnO nanoparticles in the new composite was determined using X-ray powder diffraction. The capacity of Z-G to enhance the toxicity of the anticancer drug Paclitaxel towards breast cancer cells was assessed via a cell viability study, showing the remarkable anticancer activity of the obtained system. Such results support the potential use of Z-G as an anticancer agent in combination with a common chemotherapeutic like Paclitaxel, leading to new chemotherapeutic formulations. Full article

Although an enzymatic electrochemical biosensor is a major keystone in Diabetes Mellitus management, its replacement with a low-cost and stable non-enzymatic glucose sensor (NEGS) is of high interest to scientific and industrial fields. However, most NEGS for direct glucose electrooxidation (DGE) must be performed under extreme alkaline conditions, implying additional pretreatments before detection and a limited application for on-body, real-time monitoring. Thus, research on DGE in physiological conditions is fundamental to successfully translating the current NEGS into clinical applications. In physiological conditions, drawbacks such as low current, low selectivity, and poisoning appear due to the reduction of OH ions in neutral electrolytes and the presence of chloride ions in biofluids. Therefore, an increasing number of nanomaterials based on Pt, Au, and their nanocomposites have been proposed to improve the electrochemical performance. Additionally, transition metals such as Cu, Pd, Ni, or Co combined with high surface area supports have shown promising results in increasing catalytic sites for DGE. The molecular interaction of phenylboronic acid with glucose has also been demonstrated in neutral conditions. Overall, the present review summarizes the current strategies for DGE in physiological conditions and highlights the challenges still faced for further development of functional glucose NEGS. Full article

This study investigates the properties of solution-processed hybrid polyimide (PI) nanocomposites containing a variety of nanofillers, including polyaniline copolymer-modified clay (PNEA), nanographene sheets (NGSs), and carbon nanotube sheets (CNT-PVDFs). Through a series of experiments, the flow behavior of poly(amic acid) (PAA) solution and PAA suspension containing polyaniline copolymer-modified clay (PNEA) is determined as a function of the shear rate, processing temperature, and polymerization time. It is shown that the neat PAA solution exhibits a complex rheological behavior ranging from shear thickening to Newtonian behavior with increasing shear rate and testing temperature. The presence of modified clay in PAA solution significantly reduced the viscosity of PAA. Differential scanning calorimetry (DSC) analysis showed that polyimide–nanographene sheet (PI NGS) nanocomposites processed at a high spindle speed (100 rpm) have lower total heat of decomposition, which is indicative of improved fire retardancy. The effect of processing temperature on the specific capacitance of a polyimide–CNT-PVDF composite containing electrodeposited polypyrrole is determined using cyclic voltammetry (CV). It is shown that the hybrid composite working electrode material processed at 90 °C produces a remarkably higher overall stored charge when compared to the composite electrode material processed at 250 °C. Consequently, the specific capacitance obtained at a scan rate of 5 mV/s for the hybrid nanocomposite processed at 90 °C is around 858 F/g after one cycle, which is about 6.3 times higher than the specific capacitance of 136 F/g produced by the hybrid nanocomposite processed at 250 °C. These findings show that the properties of the hybrid nanocomposites are remarkably influenced by the processing conditions and highlight the need for process optimization. Full article

Nanocomposite coatings functionalized with antimicrobial nanoparticles could be a promising alternative for the postharvest preservation of fruits. This study aimed to develop nanocomposite coatings based on pectin incorporated with zinc oxide (NPZ) nanoparticles to preserve the postharvest quality of papaya fruits. The coatings were prepared using pectin (3%) and NPZ (0%–0.4%). The materials were characterized for water-related properties (water solubility and water vapor permeability) as well as physical, mechanical, morphological, rheological, and structural properties. The coatings were applied to papaya fruits, which were analyzed for weight loss, firmness, titratable acidity, and soluble solids over nine days of storage. Incorporating NPZ (0%–0.4%) did not affect the films’ water solubility and vapor permeability. However, films with NPZ exhibited lower mechanical properties than pure pectin films. Rheological behavior testing indicated that the pectin solution was a Newtonian fluid, whereas pectin solutions with zinc nanoparticles were non-Newtonian fluids. The pectin coating with 0.2% NPZ was the most effective in preserving the postharvest quality of papaya by reducing fruit weight loss and acidity content. Therefore, the developed coatings incorporated with NPZ showed promise for the postharvest preservation of papaya fruits. Full article

Increased environmental pollution and the shortage of the current fossil fuel energy supply has increased the demand for eco-friendly energy sources. Hydrogen energy has become a potential solution due to its availability and green combustion byproduct. Hydrogen feedstock materials like sodium borohydride (NaBH₄) are promising sources of hydrogen; however, the rate at which the hydrogen is released during its reaction with water is slow and requires a stable catalyst. In this study, gold nanoparticles were deposited onto mesoporous carbon to form a nano-composite catalyst (AuNP-MCM), which was then characterized via transmission electron microscopy (TEM), powder X-ray diffraction (P-XRD), and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). The composite’s catalytic ability in a hydrogen evolution reaction was tested under varying conditions, including NaBH₄ concentration, pH, and temperature, and it showed an activation of energy of 30.0 kJ mol⁻¹. It was determined that the optimal reaction conditions include high NaBH4 concentrations, lower pH, and higher temperatures. This catalyst, with its stability and competitively low activation energy, makes it a promising material for hydrogen generation. Full article

Nanoclay-composite hydrogels represent a promising avenue for advancing bone tissue engineering. Traditional hydrogels face challenges in providing mechanical strength, biocompatibility, and bioactivity necessary for successful bone regeneration. The incorporation of nanoclay into hydrogel matrices offers a potential unique solution to these challenges. This review provides a comprehensive overview of the fabrication, physico-chemical/biological performance, and applications of nanoclay-composite hydrogels in bone tissue engineering. Various fabrication techniques, including in situ polymerization, physical blending, and 3D printing, are discussed. In vitro and in vivo studies evaluating biocompatibility and bioactivity have demonstrated the potential of these hydrogels for promoting cell adhesion, proliferation, and differentiation. Their applications in bone defect repair, osteochondral tissue engineering and drug delivery are also explored. Despite their potential in bone tissue engineering, nanoclay-composite hydrogels face challenges such as optimal dispersion, scalability, biocompatibility, long-term stability, regulatory approval, and integration with emerging technologies to achieve clinical application. Future research directions need to focus on refining fabrication techniques, enhancing understanding of biological interactions, and advancing towards clinical translation and commercialization. Overall, nanoclay-composite hydrogels offer exciting opportunities for improving bone regeneration strategies. Full article