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Magnetite nanoparticles (Fe3O4 NPs) have received considerable attention in various biomedical applications due to their fascinating properties and multiple functionalities. In this multidisciplinary study, Fe3O4 NPs were produced by an inexpensive co-precipitation technique and using four different weight percentages of Punica granatum fruit peel extract as a green stabilizer. From the image of transmission electron microscopy, the NPs showed spherical shapes with an average size of 14.38 nm. Results of UV–VIS spectroscopy and bandgap indicated successful preparation of the Fe3O4 NPs stabilized with the extract. Adding the stabilizer concentration improved the particle zeta potential from −29.24 to −35.62 mV. Thermoresponsive performance of the Fe3O4 nanofluids with the green extract could render a remarkable heating capability under the hyperthermia condition. Magnetic resonance imaging (MRI) analysis presented that the samples possessed acceptable MRI signals. An anticancer drug 5-fluorouracil was successfully loaded onto the Fe3O4 NPs containing 2 weight percentage of the extract, which indicated a maximum release of 79% in a media with pH 7.4. In cytotoxicity assays, the drug-loaded Fe3O4 NPs at 15.62 and 31.25 µg.ml−1 concentration eliminated 29% and 35% of HCT116 colorectal cancer cells, respectively. This study, therefore, introduced that the green-synthesized Fe3O4 NPs can be a promising candidate for magnetic hyperthermia therapy, MRI nanoagents and drug delivery in colorectal cancer. [ABSTRACT FROM AUTHOR]

Biosynthesis of noble metal nanoparticles is a vast developing area of research. In the present study, silver nanoparticles (Ag-NPs) are synthesized from aqueous silver nitrate through a simple and biosynthetic route using aqueous extract of Entada spiralis stem powder, which acted simultaneously as a reductant and stabilizer. The prepared samples are characterized using UV-visible, XRD, TEM, SEM, EDX, zeta potential and FTIR techniques. The formation of Ag-NPs is evidenced by the appearance of the signature brown color of the solution and UV-Vis spectra. Formation of E. spiralis/Ag-NPs is determined by UV-Vis spectroscopy, where surface plasmon resonance (SPR) absorption maxima can be observed at 400-450 nm from the UV-Vis spectrum at moderate temperature (~ 52 °C). The XRD analysis shows that the Ag-NPs at moderate temperature have a face-centered cubic structure (FCC). Well-dispersed Ag-NPs with anisotropic and isotropic morphology for E. spiralis/Ag-NPs at room and moderate temperature, with sizes of around 39.82 and 17.56 nm, are observed in TEM images. The SAED pattern exhibits the cubic lattice structure for Ag-NPs, and the d-spacing value of the crystalline structure of Ag-NPs measures around ~ 0.14 nm, which is attributed to the Ag-NPs of the (220) cubic plain at an angle of 64.78°. The spherical shapes of Ag-NPs with proper distribution for both reaction temperatures are observed in SEM images. The FTIR analysis reveals the main functional groups in the E. spiralis stem powder extract involved in the binding of Ag-NPs. The overall performance of the biosynthesis of Ag-NPs indicates that the formation of Ag-NPs using E. spiralis stem powder extract is temperature-dependent. [ABSTRACT FROM AUTHOR]

Green methods are a safer alternative to natural chemical and physical methods for the synthesis of silver nanoparticles (Ag-NPs), due to their being environmentally friendly and cost effective. This study offers a new green approach using ultrasound irradiation as the reducing agent and seaweed Kappaphycus alvarezii ( K. alvarezii) as the natural bio-media. The seaweed K. alvarezii/Ag-NPs was characterised by ultraviolet-visible (UV-vis), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope with energy dispersive X-ray (FESEM-EDX), zeta potential, and Fourier transform infrared (FTIR) studies. UV-vis shows that surface plasmon resonance (SPR) arises from this solution due to the combined oscillations from the nanoparticles. The XRD study indicates the crystalline nature of the Ag-NPs. From the TEM images, the Ag-NPs are almost spherical with an average diameter of 11.78 nm. The FTIR spectrum provides adequate evidence of phytochemicals stabilising the nanoparticles. Synthesised Ag-NPs were successfully obtained using this green method. [ABSTRACT FROM AUTHOR]

A green sonochemical method was developed for preparing silver nanoparticles (Ag-NPs) in κ-carrageenan in different concentrations of AgNO. The κ-carrageenan was used as an eco-friendly stabilizer and ultrasonic irradiation as a green reducing agent. The number of Ag-NPs increased with increasing concentrations of AgNO. Formation of Ag/κ-carrageenan was determined by UV-visible spectroscopy where the surface plasmon absorption maximum was observed at 410-416 nm. XRD analysis showed the Ag-NPs are of a face-centered cubic structure. TEM images showed the well-dispersed Ag-NPs with an average particle size <5 nm. SEM images showed the spherical shape of the Ag-NPs. The FT-IR spectrum indicated the presence of κ-carrageenan in capping the Ag-NPs. The use of photo irradiation provides a green and economic method features to the synthesis reported in this study. [ABSTRACT FROM AUTHOR]

The sonochemical method as a green method for the preparation and size control of silver nanoparticles (Ag-NPs) formed in κ-carrageenan has been developed. κ-carrageenan was chosen because it is an eco-friendly stabilizer and ultrasonic irradiation reducing agent. Formations of Ag/κ-carrageenan were determined by electronic spectroscopy where the surface plasmon absorption maxima were observed at 437-412 nm. The FT-IR spectrum indicated the presence of κ-carrageenan in capping with Ag-NPs. The XRD analysis proved that the Ag-NPs were of a face-centered cubic structure. TEM images displayed well-dispersed Ag-NPs with an average particle size of less than 10 nm. SEM images indicated the spherical shape of the Ag-NPs. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (Ag NPs) have been synthesized by using a chemical reducing method in the external space of talc layers as a solid support at room temperature. NaBH and AgNO were used as a reducing agent and silver precursor, respectively. The interlamellar space limits were without many changes and, therefore, Ag NPs formed on the exterior surface of talc composites with mean diameters 7.60-13.11 nm for different silver nitrate concentrations. The antibacterial effects of different sizes of Ag NPs in talc were investigated against Gram-positive (i.e. Staphylococcus aureus and methicillin-resistant S. aureus) and Gram-negative (i.e. Escherichia coli) bacteria by the disk diffusion method using Mueller-Hinton Agar. The AgNO was found to have significant antibacterial activity against Ag NPs that did not indicate any antibacterial effects. These results showed that Ag NPs entrapped in the surface of talc layers cannot be used as effective growth inhibitors in different biological systems. [ABSTRACT FROM AUTHOR]

This research was to apply the combination of the particle swarm optimization method and artificial neural network training with the aim of building a quantitative model to forecast the size of copper nanoparticles (Cu-NPs) prepared in sodium alginate. Sodium alginate, sodium hydroxide, copper sulfate, hydrazinium hydroxide, and ascorbic acid were used as stabilizer, pH moderator, copper precursor, reducing agent, and antioxidant, respectively. The results showed that the different sizes of Cu-NPs were obtained by changing these functions. Meaning that by increasing the amount of sodium alginate and or increase the volume of hydrazine hydrate, particle sizes of Cu-NPs were reduced. Other variables had the opposite effects due to the increase of the size of the Cu-NPs. The prediction results were remarkably in agreement with the experimental data with a correlation coefficient of 0.99 and a mean square error of 0.0058. [ABSTRACT FROM AUTHOR]

This study aims is to investigate the influence of different concentrations of Kappaphycus alvarezii ( K. alvarezii) for the synthesis of Cu@CuO core-shell nanoparticles (NPs) in aqueous solution. The core-shell NPs were prepared by a chemical reduction method using K. alvarezii, CuSO·5HO, NaOH, ascorbic acid, hydrazinium hydroxide, as stabilizer, copper precursor, pH moderator, antioxidant and reducing agent under 120 °C temperature, respectively. Formation of Cu@CuO-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@CuO-NPs were investigated by TEM, FESEM and EDXRF. The Fourier transform infrared spectrum suggested the complexation present between K. alvarezii and Cu@CuO-NPs. The study clearly showed that using various amounts of K. alvarezii leads to produce different ratios and sizes of Cu@CuO NPs. The size of the Cu@CuO-NPs decreased as the amount of K. alvarezii was increased. The ratio of Cu@CuO increases with the increasing concentration of K. alvarezii until 0.2 wt%. [ABSTRACT FROM AUTHOR]

The composite materials based on rice straw (RS) fiber and polycaprolactone (PCL) were prepared by a solution-casting method and characterized. The composites were prepared using different fiber loadings (1.0, 3.0, 5.0, and 7.0 wt%). The prepared composites (Cs) were characterized by using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), electro-optical microscopy, Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis, and mechanical properties were investigated. The XRD results showed that the intensity of the peaks decreased with the increase of RS content from 1.0 to 7.0 wt% in comparison with PCL peaks. SEM micrographs indicated poor adhesion between RS and PCL matrices, and FT-IR spectroscopy showed that, with the increase of loading percentages of RS, the intensity of the peaks is decreased from 1.0 to 7.0 wt%, and the interaction between RS and PCL was a physical interaction. Thermal stability was decreased with increasing the RS contents. Tensile measurement showed an increase in tensile modulus from 1.0 to 7.0 wt% loading of RS into the PCL, but a decrease in tensile strength and elongation at the break as the RS contents are increased, although there is a modest increase in tensile strength of the Cs material with 3.0 wt% loading of RS. [ABSTRACT FROM AUTHOR]

Artificial neural networks (ANNs) are computational tools that have found comprehensive utilization in solving many complex real world problems. Major benefits in using ANNs are their remarkable information-processing characteristics pertinent mainly to high parallelism, nonlinearity, fault and noise tolerance, and learning and generalization capabilities. An ANN approach is used to model the size of silver nanoparticles (Ag-NPs) in montmorillonite/chitosan bionanocomposites layers as a function of the silver nitrate concentration, reaction of temperature, chitosan percentage, and d-spacing of clay layers. The best ANN model is found and this final model is capable of predicting the size of nanosilver for a wide range of conditions with a mean absolute error of less than 0.004 and a regression error of about 1. Results obtained showed good ability predictive of neural network model for the prediction of the size of Ag-NPs in chemical reduction methods. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the effect of OH concentration on the size of Fe3O4 nanoparticles (Fe3O4-NPs). Fe3O4-NPs with different cubic nanocrystal structure and percentage Fe3O4 content were successfully prepared, by use of the chemical co-precipitation method, on the exterior surface of talc, as solid substrate, by an environmentally friendly process. Ferric chloride, ferrous chloride, and sodium hydroxide were used as iron oxide precursors and reducing agent. The results showed that the morphology of the Fe3O4-NPs can be adjusted by changing the reaction conditions, for example volume of reducing agent and concentration of iron salts. Different size, dispersal, and the magnetic properties were obtained by changing the concentration of iron salts and NaOH. The products were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The reaction was conducted in a non-oxidizing, oxygen-free environment. Because the interlamellar spacing of the talc was almost unchanged (ds = 0.94-0.87 nm), the Fe3O4-NPs were formed on the exterior surface of the talc. The average diameter of the Fe3O4-NCs could be varied from 6.62-8.13 nm in adjusting the concentration of NaOH. The size of the nanoparticles decreased as the amount of reducing agent was increased. These talc-Fe3O4nanocomposites (talc-Fe3O4-NCs) may have potential applications in the chemical and biological industries. [ABSTRACT FROM AUTHOR]

Hydrofluoric acid has been used as a stripping agent for molybdenum(VI) using a mixture of N,N'-carbonyl difatty amides (CDFAs) synthesized from palm oil as a extractant. The CDFAs was characterized by Fourier transform infrared spectroscopy and H nuclear magnetic resonance technique. In the extraction step, the effects of parameters, such as type of diluent, hydrochloric acid, metal concentration, and temperature, have been studied. The effects of various stripping agents on stripping efficiency have also been investigated. This work presents the development of a low-cost and environmentally friendly extractant to recover molybdenum. [ABSTRACT FROM AUTHOR]

Artificial neural networks have been widely used to solve problems because of their reliable, robust, and salient characteristics in capturing nonlinear relationships between variables in complex systems. In this study, a wavelet neural network (WNN) based on the incremental backpropagation (IBP) algorithm was used in conjunction with an experimental design. To optimize the network, independent variables including ion concentration, adsorbent dose, and removal time were used as input parameters, while the removal percentage of Pb(II), Ni(II), and Cu(II) by magnetic/talc nanocomposite were selected as outputs. The network was trained by the IBP and four other algorithms as a model. To determine the number of hidden-layer nodes in the model, the root-mean-square error of a testing set was minimized. After minimizing this error, the topologies of the algorithms were compared based on the coefficient of determination and absolute average deviation. This comparison indicated that the IBP algorithm had the minimum root-mean-square error and absolute average deviation, and maximum coefficient of determination, for the test dataset. The importance values included 35.16 % for initial ion concentration, 32.74 % for adsorbent dose, and 32.11 % for removal time, showing that none of these were negligible. These results show that the WNN has great potential ability for prediction of removal of heavy-metal ions from aqueous solution with residual standard error less than 1.2 %. [ABSTRACT FROM AUTHOR]

Green biological synthesis of metallic nanoparticles is an important method in improved techniques of eco-friendly nanoparticle production. In the present study, gold nanoparticles (Au-NPs) were synthesized using of the brown marine algae Sargassum muticum (S. muticum) aqueous extract as both a reductant and a capping agent. The treatment of aqueous solution of gold precursors with S. muticum algae extract resulted in rapid formation of stable nanoparticles for gold. The growth of nanoparticles is monitored by UV-Vis spectrophotometer and complemented with characterization using transmission electron microscopy (TEM), X-ray diffraction, and zeta potential. The formation of Au-NPs was confirmed through the presence of an absorption peak at 550 nm using a UV-Vis spectrophotometer. A TEM image showed that the particles are spherical in shape with a mean size of 5.42 ± 1.18 nm. The capping of anionic bio-compounds on the surface of nanoparticles was confirmed by zeta potential measurement (−35.8 mV) and is responsible for the electrostatic stability. The bio-synthesized Au-NPs are expected to have notable applications in pharmaceutical and biomedical applications. [ABSTRACT FROM AUTHOR]