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Three samples of Fe−S were prepared with different hydrothermal periods (6, 12, and 18 h). X‐ray diffraction (XRD) test showed that the first produced sample contained 42.3 wt % of magnetite, 35 wt % of greigite, and 22.7 wt % of pyrite phases. The same phases were formed during the second period but with different wt % ratios. The greigite increased to 67.8 wt % by the third period, while the magnetite and pyrite phases vanished and were associated with a low ratio of the presence of pyrrhotite and FeO2. Scanning electron microscope (SEM) images confirmed the formation of the nanoparticles. The increase in the hydrothermal time produced a reduction in the saturation magnetization (39.8 to 9.1) emu/g and the remanence magnetization (8 to 2.4) emu/g, and increasing in the coercivity. To assess the viability of Michigan Cancer Foundation‐7 (MCF‐7) and hemolytic disease of the fetus and newborn (HdFn) cells, a colorimetric assay for assessing cell metabolic activity (MTT) was applied to the third sample. The outcome verified iron sulfide's cytocompatibility against HdFn cells even at high concentrations and good anticancer activity against MCF‐7 cell lines. The result of the DPPH test confirmed that the third sample had antioxidant activity equivalent to that of ascorbic acid. [ABSTRACT FROM AUTHOR]

Since the development of bacterial resistance towards antibiotics has the potential to limit the effectiveness of antibiotics in the treatment of infectious diseases, it is necessary to try different strategies to provide alternatives. In order to solve the problems, this work used silver nanoparticles‐loaded polydopamine‐modified montmorillonite (AgNP/PDA−Mt) to cope with the infection of the gram‐negative bacteria Escherichia. Coli and the gram‐positive bacteria Staphylococcus. aureus. Polydopamine‐modified montmorillonite (PDA−Mt) was used to reduce silver ions into silver nanoparticles through the hydroxyl groups of polydopamine. The chemical properties and morphology of AgNP/PDA−Mt were analyzed by X‐ray diffraction spectroscopy (XRD), fourier transform infrared spectroscopy (FT‐IR), transmission electron microscope (TEM), scanning electron microscope (SEM), etc. Also, its antimicrobial property has been investigated. The results showed that AgNP/PDA−Mt possessed significant sterilization at low doses. And the results had been shown its acceptable biocompatibility. [ABSTRACT FROM AUTHOR]

Sulfonic acid functionalized silica coated cobalt ferrite nanoparticles (CoFe2O4/SiO2−SO3H) was prepared as an efficient solid acid catalyst for the green synthesis of dihydropyrimido[4,5‐b]quinolinetrione derivatives. CoFe2O4 NPs were prepared by co‐precipitation method and then the silica‐coated CoFe2O4 NPs were modified with chlorosulfonic acid. Obtained CoFe2O4/SiO2−SO3H was characterized by thermo gravimetric analysis (TGA), Fourier transform‐infrared spectroscopy (FT‐IR), scanning electron microscope (SEM), energy‐dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD) and vibrating‐sample magnetometer (VSM). The magnetically separable CoFe2O4/SiO2−SO3H was successfully used for the four component reaction of barbituric acid, dimedone, amines (or ammonium acetate) and benzaldehyde derivatives for the synthesis of dihydropyrimido[4,5‐b]quinolinetriones under thermal and ultrasound conditions. The advantages of presented simple protocol are the easily separation of magnetic catalyst from the reaction medium by an external magnet, short reaction times, green reaction conditions in addition to simple workup and high yield of products. [ABSTRACT FROM AUTHOR]

ZnO/ZrO2 samples were obtained by impregnation ZnO on three different ZrO2 polymorphic phases: monoclinic, tetrahedral and amorphous. The catalysts were tested for CO2 hydrogenation to methanol and the structure was determined using nitrogen physisorption, scanning electron microscope (SEM), Fourier transform infrared (FT‐IR) pyridine adsorption, hydrogen temperature‐programmed desorption (H2‐TPD), CO2‐TPD and X‐ray photoelectron spectroscopy (XPS). The results showed that the ZnO/tm‐ZrO2‐500 catalyst, with a mixture of both tetrahedral and monoclinic ZrO2 phases, had the highest CH3OH yield among all the samples. The yield of methanol is correlated to the lattice oxygen content for all the catalysts. During the reaction, formate and methoxy species seemed to be the active intermediate species. [ABSTRACT FROM AUTHOR]

Metal matrix composites with yttria as reinforcement are mostly produced because of it's improved mechanical properties while thermal stability, electrochemical and magnetic properties of the yttria based composites are rarely considered. In the present study, the feasibility of incorporating yttria nanoparticles into nickel matrix from ethylene glycol bath by electro‐codeposition method is demonstrated. The particle content of the coatings was strongly influenced by current density i. e. the rate of metal deposition. Particle content, surface morphology and microstructural changes of the deposits were investigated by scanning electron microscope (SEM) equipped with energy dispersed X‐ray analyzer (EDAX). A dense, compact and smoother composite surface with lower particle content was obtained at higher current densities. Crystallographic structure, texture and lattice strain have been evaluated using X‐ray diffraction (XRD). Incorporation of yttria particles inhibits the grain growth and causes grain refinement of the nickel matrix. Annealed nanocomposite deposits revealed thermal stability up to 700 °C. The comparative electrochemical corrosion behavior of the electrodeposited coatings in 3.5 % NaCl solution and their deposition potential were evaluated. Magnetic studies showed nearly complete absence of hysteresis i. e. soft magnetic nature of the coatings. [ABSTRACT FROM AUTHOR]

Nanozymes exhibit excellent enzyme‐like activities but lack specificity. Here, molecularly imprinted polymers (MIPs) based on polypyrrole (PPy) and using methylene blue (MB) as template were grown on Fe3O4 nanozymes to enhance the catalytic selectivity. The obtained composite Fe3O4@PPy MIPs were characterized using a scanning electron microscope, transmission electron microscope, powder X‐ray diffractometer, and vibrating sample magnetometer. The PPy‐encapsulated Fe3O4 nanozymes retained their catalytic ability and almost completely removed MB within 30 min in the presence of sodium persulfate. In comparison with bare Fe3O4 nanozymes, the Fe3O4@PPy MIPs showed superior catalytic selectivity for MB. The apparent rate constants (kapp) for MB, rhodamine B, and methyl orange were 0.073, 0.035, and 0.012 min−1, respectively. Even after five recycling steps, the obtained Fe3O4@PPy MIPs could degrade more than 80% of MB. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (Ag‐NP‐AE) are synthesized and stabilized by the extract of an ethnomedicine, Albizia lebbeck bark aqueous extract (AE). Ag‐NP‐AE is active against several multidrug‐resistant (MDR) clinical isolates. The nanoparticles are characterized by UV‐vis spectroscopy, Fourier‐transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and X‐ray diffraction (XRD) studies. The antibacterial potency of Ag‐NP‐AE is determined by Disc diffusion, Agar and Broth dilution assays against 14 MDR isolates along with their minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The growth kinetics was determined by quantification of colonies; while toxicity by quantification of viable cells. The Ag‐NP‐AE shows free‐radical scavenging activity at 15–20 μM and is non‐toxic up to 50 μM but demonstrated significant antibacterial activity against all the test isolates with zone diameter of 10.4–19.5 mm and MIC of 0.5–0.84 μM (0.085‐0.143 μg); while the zone diameter with AE was 10.2–15 mm and MIC of 128–1024 μg/mL, respectively; while 100 % killing was observed at 0.50 μM within 2–4 h of exposure due to damage of cellular architectures. [ABSTRACT FROM AUTHOR]

A new type of reverse osmosis (RO) membrane incorporating S‐Beta zeolite nanoparticles was synthesized through interfacial polymerization of m‐phenylenediamine and trimesoyl chloride on the surface of nanoporous membrane support. The presence of S‐Beta zeolite in the polyamide layer of RO membrane was detected by scanning electron microscope equipped with energy dispersive X‐ray spectroscope. The impacts of S‐Beta zeolite loading ranging from 0.01 to 0.1 wt% on the separation performance of membrane were further studied and the results showed that the optimal S‐Beta zeolite for RO membrane was at 0.05 wt%. Compared to the control RO membrane without nanoparticles that showed water flux of 25.36 L/(m2.h) and NaCl rejection of 97%, the membrane incorporated with optimal zeolite loading exhibited better performance (65.25 L/(m2.h) and 97.33%) when tested using 1500 ppm NaCl solution at 300 psi. [ABSTRACT FROM AUTHOR]