Synthesis of talc/Fe3O4 magnetic nanocomposites using chemical co-precipitation method.

The aim of this research was to synthesize and develop a new method for the preparation of iron oxide (Fe3O4) nanoparticles on talc layers using an environmentally friendly process. The Fe3O4 magnetic nanoparticles were synthesized using the chemical co-precipitation method on the exterior surface layer of talc mineral as a solid substrate. Ferric chloride, ferrous chloride, and sodium hydroxide were used as the Fe3O4 precursor and reducing agent in talc. The talc was suspended in deionized water, and then ferrous and ferric ions were added to this solution and stirred. After the absorption of ions on the exterior surface of talc layers, the ions were reduced with sodium hydroxide. The reaction was carried out under a nonoxidizing oxygen-free environment. There were not many changes in the interlamellar space limits (d-spacing=0.94-0.93nm); therefore, Fe3O4 nanoparticles formed on the exterior surface of talc, with an average size of 1.95-2.59nm in diameter. Nanoparticles were characterized using different methods, including powder X-ray diffraction, transmission electron microscopy, emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. These talc/Fe3O4 nanocomposites may have potential applications in the chemical and biological industries

Polysulfone mixed-matrix membrane incorporating talc clay particles for gas separation

Mixed-matrix membranes (MMMs) have showed advantages in membrane-based gas separation in recent years. However, there is still intensive demand for the development of membranes incorporated by proper fillers for further enhancement of gas separation performance. In this study, mixed-matrix membrane (MMMs) has been synthesized by incorporating of different content of talc into polysulfone (PSf) polymer specifically upon the separation of carbon dioxide from methane. The influence of filler content on the gas separation performance of the fabricated membranes was studied. The prepared MMMs were analyzed by thermal gravimetric analysis (TGA), X-ray diffraction (XRD), derivative thermo-gravimetric (DTG), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and pure gas permeation testing. XRD analysis suggested that talc layers crystalline structure was changed slightly due to blending and just limited PSf chain intercalation occurred. The results showed that the rate of gas permeation increased with increasing talc content while the selectivity declined at 0.5 wt% due to filler agglomeration as confirmed by FESEM. The best results were obtained at 0.1 wt% talc compared to neat PSf with superior gas separation behavior

Effect of seaweed Kappaphycus alvarezii in the synthesis of Cu@Cu2O core–shell nanoparticles prepared by chemical reduction method

This study aims is to investigate the influence of different concentrations of Kappaphycus alvarezii (K. alvarezii) for the synthesis of Cu@Cu2O core–shell nanoparticles (NPs) in aqueous solution. The core–shell NPs were prepared by a chemical reduction method using K. alvarezii, CuSO4·5H2O, NaOH, ascorbic acid, hydrazinium hydroxide, as stabilizer, copper precursor, pH moderator, antioxidant and reducing agent under 120°C temperature, respectively. Formation of Cu@Cu2O-NPs was determined by UV–Vis spectroscopy where surface plasmon absorption maxima can be observed at 390-590 nm. The synthesized core–shell NPs were also characterized by X-ray diffraction. Moreover, the morphology and structure of the K. alvarezii/Cu@Cu2O-NPs were investigated by TEM, FESEM and EDXRF. The Fourier transform infrared spectrum suggested the complexation present between K. alvarezii and Cu@Cu2O-NPs. The study clearly showed that using various amounts of K. alvarezii leads to produce different ratios and sizes of Cu@Cu2O NPs. The size of the Cu@Cu2O-NPs decreased as the amount of K. alvarezii was increased. The ratio of Cu@Cu2O increases with the increasing concentration of K. alvarezii until 0.2 wt%

Enhancement of heavy metals sorption via nanocomposites of rice straw and Fe3O4 nanoparticles using artificial neural network (ANN)

The artificial neural network (ANN) modeling of adsorption of Pb(II) and Cu(II) was carried out for determination of the optimum values of the variables to get the maximum removal efficiency. The input variables were initial ion concentration, adsorbent dosage, and removal time, while the removal efficiency was considered as output. The performed experiments were designed into two data sets including training, and testing sets. To acquire the optimum topologies, ANN was trained by quick propagation (QP), Batch Back Propagation (BBP), Incremental Back Propagation (IBP), genetic algorithm (GA) and Levenberg-Marquardt (LM) algorithms for testing data set. The topologies were defined by the indicator of minimized root mean squared error (RMSE) for each algorithm. According to the indicator, the IBP-3-9-2 was selected as the optimized topologies for heavy metal removal, due to the minimum RMSE and maximum R-squared

Synthesis and characterization of rice straw/Fe3O4 nanocomposites by a quick precipitation method

Small sized magnetite iron oxide nanoparticles (Fe3O4-NPs) with were successfully synthesized on the surface of rice straw using the quick precipitation method in the absence of any heat treatment. Ferric chloride (FeCl3·6H2O), ferrous chloride (FeCl2·4H2O), sodium hydroxide (NaOH) and urea (CH4N2O) were used as Fe3O4-NPs precursors, reducing agent and stabilizer, respectively. The rice straw fibers were dispersed in deionized water, and then urea was added to the suspension, after that ferric and ferrous chloride were added to this mixture and stirred. After the absorption of iron ions on the surface layer of the fibers, the ions were reduced with NaOH by a quick precipitation method. The reaction was carried out under N2 gas. The mean diameter and standard deviation of metal oxide NPs synthesized in rice straw/Fe3O4 nanocomposites (NCs) were 9.93 ± 2.42 nm. The prepared rice straw/Fe3O4-NCS were characterized using powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDXF) and Fourier transforms infrared spectroscopy (FT‒IR). The rice straw/Fe3O4-NCs prepared by this method have magnetic properties

Evaluation of heavy metals removal by cross-linked (polyvinyl alcohol/chitosan/magnetic) nano fibrous membrane prepared by electro spinning technique

In this study, chitosan/polyvinyl alcohol (PVA)/magnetic nano fibrous membrane was fabricated via electro spinning. First, magnetic nano particles with average size of 7.98 nm, were fabricated using co-precipitation method. Then, chitosan solution was blended with aqueous PVA solution in different weight ratios. The electro spun fibers were kept in a glass desiccator saturated with (50% aqueous solution) of glutaraldehyde vapor for 24 h. Morphological analysis of chitosan/PVA electro spun nano fibrous showed a defect-free nano fiber material with 50:50 weight ratio of chitosan/PVA. Subsequently, 1 wt.% of magnetic nano particles was added to 50:50 chitosan/PVA solution and then, fine bead free nano fibrous electro spun was fabricated. The resulting nano fiber was characterized with field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-Ray diffraction, Fourier transform infrared spectroscopy, swelling test, and adsorption test. The resulting membrane was stable in distilled water, acidic, and basic media overnight. Moreover, the adsorption ability of nano fibrous membrane was studied over Cr6+, Pb2+, and Ni2+ ions. Kinetic parameters were estimated using the first-order and pseudo-second-order models. Kinetic study showed that adsorption rate was high. Therefore, chitosan/polyvinyl alcohol (PVA)/magnetic nano fibrous membrane can be a useful material for water treatment at moderate concentration of heavy metals

Rapid and high capacity adsorption of heavy metals by Fe3O4/montmorillonite nanocomposite using response surface methodology: preparation, characterization, optimization, equilibrium isotherms, and adsorption kinetics study

Fe3O4/montmorillonite nanocomposite (Fe3O4/MMT NC) was synthesized for removal of Pb2+, Cu2+ and Ni2+ ions from aqueous systems. The nanoadsorbent was characterized by X-ray diffraction and transmission electron microscopy and mean diameter of magnetic nanoparticles was about 8.24 nm. The experiments were designed by response surface methodology and quadratic model was used to prediction of the variables. The adsorption parameters of adsorbent dosage, removal time, and initial heavy metal ions concentration were used as the independent variables and their effects were investigated on the heavy metal ions removal. Variance analysis was utilized to judge the adequacy of the chosen models. Optimum conditions with initial heavy metal ions concentration of 510.16, 182.94, and 111.90 mg/L, 120 s of removal time and 0.06 g/0.025 L, 0.08 g/0.025 L, and 0.08 g/0.025 L of adsorbent amount were given 89.72%, 94.89%, and 76.15% of removal efficiency Pb2+, Cu2+ and Ni2+ ions, respectively. Prediction of models was in good agreement with experimental results and Fe3O4/MMT NC was found successful in removing heavy metals from their aqueous solutions

Immobilization of bovine serum albumin on the chitosan/PVA film

Chitosan/polyvinyl alcohol (Chitosan/PVA) blended film was prepared by direct blend process and solution casting methods. In order to reduce the swelling ratio and enhance the chemical and mechanical stability, Chitosan/PVA film was cross-linked with glutaraldehyde in order to produce Chitosan-g-PVA. Bovine serum albumin (BSA) was used as a model protein to incorporate into the Chitosan-g-PVA. The chemical structure and morphological characteristics of films were studied by FT-IR and scanning electron microscopy (SEM). Mechanical and physical properties of blended films such as tensile properties in the dry and wet states, water uptake and water contact angle measurement were characterized. Blending PVA and chitosan improved strength and flexibility of the films. Crosslinking with glutaraldehyde further improves the tensile strength and decrease the hydrophilicity of films. BSA immobilized on the Chitosan-g-PVA film was calculated as BSA encapsulation efficiency

Synthesis and characterization of Zeolite/Fe3O4 nanocomposite by green quick precipitation method.

A green quick precipitation method was successfully used for synthesis of magnetic iron oxide nanoparticles (Fe3O4-NPs) on the surface of sodium/potassium type zeolite. Ferric chloride, ferrous chloride and sodium hydroxide aqueous solutions were used in the synthesis and coating of the Fe3O4-NPs on the surface of the zeolite to produce the zeolite/magnetic iron oxide nanocomposite (zeolite/Fe3O4 –NCs). The reaction was performed in aqueous suspension phase under the ambient condition as green chemistry method. Characterization with Fourier transforms infrared spectroscopy (FT‒IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDXF) and transmission electron microscopy (TEM) confirmed the formation of Fe3O4-NPs with mean particle sizes of 3.55±1.02 nm on the surface of the zeolite

Preparation and characterization of Fe₃O₄/montmorillonite and Fe₃O₄/talc nanocomposites for removal of heavy metals

Toxic metal contamination in water systems is a serious problem threating environment. Many researches have been done to develop effective ways for the heavy metals removal. Traditionally methods used for removal have some disadvantages, such as low efficiency and high cost. Adsorption is one of the techniques use in this area due to its effectiveness and easy operation. In this work, Fe3O4/montmorillonite and Fe3O4/talc nanocomposites as nanoadsorbent were prepared by co-precipitation method in different percentages. The suitability of the magnetic nanocomposites for the adsorption of Cu2+, Ni2+ and Pb2+ ions and its efficiency were investigated. The Response Surface Methodology was used for designing the experiment sets. The analysis of variance for Cu2+, Ni2+ and Pb2+ removal was used to estimate the response of initial concentration of heavy metal ion (mg/L), removal time (s) and dosage of adsorbent (g). Transmission electron microscopy showed that the average nanoparticles size were between 8.24 to 12.88 and 6.62 to 8.13 nm for Fe3O4/montmorillonite and Fe3O4/talc nanocomposites, respectively. Scanning electron microscopy showed that the nanoparticles were highly uniform in size and spherical shape. X-ray diffraction and Energy-dispersive X-ray, confirmed that magnetic nanoparticles were prepared. Vibrating sample magnetometer reveals the nanoparticles were superparamagnetic. The Fe3O4/montmorillonite nanocomposite showed a better capability for adsorption of heavy metals from aqueous solution. The best interpretation for the equilibrium data was given by Langmuir isotherm and the kinetic data showed that the adsorption process followed the pseudo-second order kinetic model for both adsorbents. According to RSM results, for Fe3O4/montmorillonite nanocomposite, removal efficiency were 89.72%,94.89%, and 76.15% while the removal time was 120s, Fe3O4/montmorillonite nanocomposite amount were 0.06, 0.08 and 0.08 g and initial heavy metal concentrations were 510.16 for Cu2+, 182.94 for Ni2+ and 111.90 mg/L for Pb2+. Moreover for Fe3O4/talc nanocomposite, removal efficiency were 72.15%, 50.23%, and 91.35% while the removal time was 120s, Fe3O4/talc nanocomposite amount was 0.12 g and initial heavy metal concentrations were 100 for Cu2+, 92 for Ni2+ and 270 mg/L for Pb2+ ions. As a results two unique nano adsorbents made of montmorillonite and talc as a natural substrate and loaded magnetic nano particles were used to rapid remove of Cu2+, Ni2+ and Pb2+ ions from aqueous solution. The adsorbents can easily separate by an external magnetic field