In this article, the casting method was used to prepare poly(methyl methacrylate)/hydroxyapatite (PMMA/HA) nanocomposite flms incorporated with diferent contents (0.5, 1, and 1.5 wt%) of graphene nanoplatelets (Gnp). The chemical properties and surface morphology of the PMMA/HA blend and PMMA/HA/Gnp nanocomposite were characterized using FTIR, and SEM analysis. Besides, the thermal conductivity, dielectric and electrical properties at (1–107 Hz) of the PMMA/HA blend and PMMA/HA/Gnp composites were investigated. The structural analysis showed that the synthesized composites had a low agglomerated state, with multiple wrinkles of graphene fakes in the PMMA/HA blend. The thermal conductivity was improved by more than 35-fold its value for pure PMMA. The AC and DC electrical conductivities of PMMA/HA/Gnp composites were enhanced with increasing the amount of Gnp and the estimated exponent (s) being between 1.25 and 1.3. The values of the real part (ɛ′) and imaginary part (ε′′) of the dielectric constant as well as electrical impedance depend on the Gnp ratio. The value of ɛ′ was reduced at the lower frequency (< 105  Hz) and became constant at the higher frequency which attributed to the relaxation time. The values of ε″ are small at low frequencies and increase with increased frequency due to the electronic polarization efects as well as to the dipoles not beginning to follow the feld variation at higher frequencies. The increase in the dielectric loss, tan(δ), with an increase in Gnp content, to 0.5 wt%, due to the interfacial polarization mechanism occurred in the composite’s flms corresponding to frequencies.

The direct impregnation approach is used to synthesize nickel dimethylglyoxime (NDG) on γ-alumina (γ-Al2O3) composites to be used as a catalyst. The structural, thermal, and magnetic characteristics of γ-Al2O3, NDG, and NDG/γ-Al2O3 composites are investigated and their photocatalytic performance towards methylene blue (MB) and methyl orange (MO) is examined. The fnding supports the use of NDG over γ-Al2O3 as catalysts, besides their enhanced thermal stability. The scanning electron microscope (SEM) and transmission electron microscopy (TEM) demonstrate that the catalyst particles are dispersed uniformly, indicating that the Ni microcrystalline or Ni nanoparticles on γ-Al2O3 are most likely distributed in a single phase and/or in a homogenous route. X-ray difraction (XRD) results together with the results of SEM and TEM indicated that NDG/γ-Al2O3 nanocomposite catalysts can be prepared efectively by impingement approach. The average crystallite size of γ-Al2O3 is 6 nm, whereas the average crystallite size of NDG/γ-Al2O3 composites is 10 nm. Both γ-Al2O3 and NDG/γAl2O3 composites have a weakly diamagnetic response, whereas NDG exhibits poor ferromagnetism response. The calculated values for the photodegradation efciency, after UV–visible irradiation for 130 min, towards MO dye employing γ-Al2O3, NDG, and NDG/γ-Al2O3 composites as a catalyst are 74.2, 36.7, and 61.7%, respectively, whereas their values towards MB dye are 17.8, 5.3, and 19.1%, respectively. Furthermore, when NDG was combined with γ-Al2O3 to form NDG/γ-Al2O3 composites, the degradation performance was signifcantly improved and could be suitable for the degradation of other dyes.

Functionalizing organic–inorganic materials for use in packaging technologies, such as polymers wrapped in thin metal, has proven to be one of the more successful strategies. In this study, the direct current (DC) sputtering technique under a vacuum of 3× 10−5 Torr was used to deposit silver (Ag) flms of thicknesses of 100 and 300 nm on poly (methyl methacrylate) (PMMA) polymer. The structural, optical, antibacterial activity, and wettability properties of Ag/PMMA were carried out using X-ray difraction (XRD), Fourier-transform infrared spectroscopy (FTIR), feld emission scanning electron microscope (FE-SEM), atomic force microscopy (AFM), UV spectrophotometer, and contact angle. The cubic crystal structure phase of Ag was confrmed by the XRD. The Ag coating layer has consistent nanomorphology, according to AFM, and the PMMA substrate surface was well coated with Ag nanoparticles. As the Ag flm thickness rose, the optical band gap values of Ag/PMMA slightly increased. In addition, it has been found that these optical characteristics such as extension coefcient, optical density, and optical surface resistance essentially depend on the thickness of the Ag layers. Both samples of pure PMMA and Ag/PMMA polymers show no activity against E. coli. In the meantime, S. aureus activity is detected in the Ag/PMMA samples, and the antibacterial activity is slightly infuenced by the Ag thickness. The contact angle rose as the Ag flm thickness grew over the PMMA, resulting in a decrease in the wettability of the liquid which is required for food packaging technology.

A study of the spectroscopic properties, as well as polarizability and optical basicity of TeO2–B2O3 glasses doped with CuO using density, XRD, and UV–Vis analysis, is presented in this paper. The TeO2–B2O3 – CuO glasses are fabricated using the melt-quenching method. The glasses proved to be amorphous in nature from the XRD which was confirmed by the UV–Vis spectra. The peak observed in the pattern of the 0% CuO sample represents the presence of a crystalline phase of α-TeO2 and/or γ-TeO2. Important optical and physical parameters are discussed such as the refractive index (2.318–2.378), metallization criterion (0.4069–0.3919), optical basicity (0.7995–0.8057), electronic polarizability (0.2358–0.2410), linear dielectric susceptibility (0.3480–0.3704 esu), and third order non-linear dielectric susceptibility (1.466 × 1012–1.882 × 1012 esu). Based on the refractive index, metallization criterion, electronic polarizability, optical basicity, and dielectric susceptibility values, the glasses could present great potential applications in fiber optics and laser applications.

This article has attempted to establish eco-friendly organic PVA/Al2O3 nanocomposite membranes and estimate the effectiveness of different additives (1, 2, and 3 wt%) of alumina (Al2O3) nano-filler in PVA matrix on their structural and optical properties for establishing their suitability in photonic applications. Al2O3 nano-filler dispersed in the PVA matrix has been synthesized via the solvent casting technique. The structure of synthesized PVA/Al2O3 nanocomposite membranes has been characterized by Fourier transform-infrared (FTIR), Raman spectroscopy, and X-ray diffraction (XRD). Upon introducing the Al2O3 nano-filler in the PVA matrix, the self-hydrogen bonding between the PVA chains was weakened while hydrogen bonding with Al2O3 was generated. In addition, optical, dielectric, and dispersion analysis suggested that even though the Al2O3 nano-filler in PVA/Al2O3 nanocomposite membranes aided in regularly folding the PVA polymer chains. Moreover, formed new structural defects, disorders, and impurities can be used for tuning the PVA/Al2O3 nanocomposites for optoelectronic applications and for making efficient absorbents for environmental treatments.

Graphitic carbon nitride (CN) has emerged as a highly promising material in the photocatalysis field. However, its bulk structure suffers from a lack of active sites, limiting its practical application. Herein, a boron-doped CN (BCN) was prepared by a green gas-blowing-assisted thermal polymerization and then subjected to different exfoliation processes in order to delaminate the layered structure and tune the surface-active sites. A thorough comparative study shows that thermal exfoliation creates unsaturated nitrogen sites and induces the formation of interconnected layers that act as an electron diffusion channel for better charge transport. Furthermore, the thermally exfoliated BCN is rich in structural disorders that serve as dissociation defects for photoinduced charge carriers with a low exciton binding energy of 27 meV. Experimental results supported by theoretical calculations show that the nitrogen adjacent to 

Utilization of g-C₃N₄ as a single photocatalyst material without combination with other semiconductor remains challenging. Herein, we report a facile green method for synthesizing a metal free modified g-C₃N₄ photocatalyst. The modification process combines four different strategies in a one-pot thermal reaction: non-metal doping, porosity generation, functionalization with amino groups, and thermal oxidation etching. The as-prepared amino-functionalized ultrathin nanoporous boron-doped g-C₃N₄ exhibited a high specific surface area of 143.2 m² g⁻¹ which resulted in abundant adsorption sites for CO₂ and water molecules. The surface amino groups act as Lewis basic sites to adsorb acidic CO₂ molecules, which can also serve as active sites to facilitate hydrogen generation. Besides, the simultaneous use of ammonium chloride as a dynamic gas bubble template along with thermal oxidation etching …

Here, we demonstrate the SnS/g-C₃N₄ crystallized and nanostructured photocatalysts for efficient and selective CO₂ conversion to CH₄ by engineered thermal evaporation and the decoration of g-C₃N₄ through a simple dipping method, overcoming the limitation of bulk SnS-based photocatalysts. The SnS/g-C₃N₄ nanostructured photocatalysts exhibit a superior methane production rate of 387.5 μmol∙m⁻²∙h⁻¹ (= c.a. 122.33 μmol∙g⁻¹∙h⁻¹) with an apparent quantum yield of c.a. 9.7% at 520 nm with engineered lengths. Moreover, 100% selective production toward CH₄ is also measured from the SnS/g-C₃N₄ photocatalysts, with > 10 h stable operation. These performances are, to the best of our knowledge, the highest production rate among reported photocatalytic films and metal sulfide/g-C₃N₄ composite-based photocatalysts. These highly improved performances are attributed to synergistic effects by the …

Cancer is a complex and heterogeneous disease and is still one of the leading causes of morbidity and mortality worldwide, mostly as the population ages. Despite the encouraging advances made over the years in chemotherapy, the development of new compounds for cancer treatments is an urgent priority. In recent years, the design and chemical synthesis of several innovative hybrid molecules, which bring different pharmacophores on the same scaffold, have attracted the interest of many researchers. Following this strategy, we designed and synthetized a series of new hybrid compounds that contain three pharmacophores, namely trimethoxybenzene, thiazolidinedione and thiazole, and tested their anticancer properties on two breast cancer (MCF-7 and MDA-MB-231) cell lines and one melanoma (A2058) cell line. The most active compounds were particularly effective against the MCF-7 cells and did not affect the viability of the normal MCF-10A cells. Docking simulations indicated the human Topoisomerases I and II (hTopos I and II) as possible targets of these compounds, the inhibitory activity of which was demonstrated by the mean of direct enzymatic assays. Particularly, compound 7e was proved to inhibit both the hTopo I and II, whereas compounds 7c,d blocked only the hTopo II. Finally, compound 7e was responsible for MCF-7 cell death by apoptosis. The reported results are promising for the further design and synthesis of other analogues potentially active as anticancer tools.

In recent years, the number of people suffering from cancer has risen rapidly and the World Health Organization and U.S. and European governments have identified this pathology as a priority issue. It is known that most bioactive anticancer molecules do not target a single protein but exert pleiotropic effects, simultaneously affecting multiple pathways. In our study, we designed and synthesized a new series of silver N‐heterocyclic carbene (NHC) complexes [(NHC)₂Ag]⁺[AgX₂]⁻ (X=iodide or acetate). The new complexes were active against two human breast cancer cell lines, MCF‐7 and MDA‐MB‐231. These compounds showed multiple target actions as anticancer, by inhibiting in vitro the activity of the human topoisomerases I and II and interfering with the cytoskeleton dynamic, as also confirmed by in silico studies. Moreover, the antimicrobial activity of these silver complexes was studied against Gram …