JOURNAL OF NANOSTRUCTURE IN CHEMISTRY
Year:2019 | Volume:9 | Issue:3|Papers Count:8

A novel 0. 5(BaZrO3)– 0. 5(CoFe2O4) (BZ– CF) nanocomposite ceramics has been synthesized using sol– gel autocombustion and mixing technique. The structural analysis was carried out using X-ray diffraction (XRD) technique. The XRD pattern shows mixed perovskite and spinel ferrite phases with simple cubic structure for the BZ– CF nanocomposite. The calculated average crystallite size of the samples varies of the order of the nanoregime. The lattice parameter (a) and other structural parameter were obtained using XRD data and it is found that the structural data of pure parent ceramics were in the reported range. The surface morphology of grains of the present samples was examined using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The FESEM images show spherical particles with average grain size in the nanometer range. Compositional stoichiometry was confirmed by energy dispersive spectrum (EDX) analysis. Fourier-transform infrared spectra (FTIR) of barium zirconate (BZ) and cobalt ferrite (CF) confirmed the perovskite and spinel ferrite structure, respectively. However, the FTIR spectrum of BZ– CF nanocomposite confirmed the change in crystal structure due to mixed phases. The M– H curves recorded at room temperature using pulse field hysteresis loop tracer technique exhibits a weak hysteresis loop for BZ– CF nanocomposite, perfectly diamagnetic nature for BZ nanoceramics, and typical ferromagnetic hysteresis loop for pure CF nanoceramics.

The Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) can bind drugs and act as drug-carriers. The magnetically active SPIONs can be used to deliver the drugs to the target through magnetic fields. The objective of the present work has been undertaken to study the stability, and binding behaviour of procaine with SPIONs and surfactant-coated SPIONs. Procaine is among the ester drugs and hydrolyses in the alkaline medium. The influence of SPIONs and surfactant-coated SPIONs on the rate of hydrolysis of procaine in alkaline medium may help to define the behaviour of the drug in the presence of these nanoparticles. The kinetic studies of procaine hydrolysis in the presence of SPIONs and surfactant-coated SPIONs were carried out spectrophotometrically. The concentrations of OH− ions were taken in excess over [procaine] to keep the reaction conditions under pseudo-first-order. The presence of SPIONs and the SPIONs coated with cetyltrimethylammonium bromide; CTABr and sodium dodecylsulphate; SDS surfactants displayed an inhibitive effect on the rate of hydrolysis of procaine. The synthesised nanoparticles were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The kψ-[surfactant] profile in the presence of SPIONs was discussed using the pseudophase model in which the reactants are considered to be distributed in the aqueous and micellar media. The rate constant for the procaine hydrolysis and the binding constants of procaine with coated and non-coated SPIONs have been calculated by analysing the data for the variation in the rate constant with the change in [surfactant], [SPIONs] and [surfactant-coated SPIONs].

To develop a process of fine particle production by spray pyrolysis, spray combustion of W/O (water-in-oil) emulsion, of which water phase was raw material solution and oil phase was fuel for heat source of high-temperature reaction field, was investigated. In this study, nickel oxide particles, which were a preliminary step of the nickel fine particle production, were synthesized and its structural characteristics were evaluated. Mixed solution of nickel nitrate and white kerosene was used as raw material. W/O emulsions were prepared using ultrasonic homogenizer and stirring these raw materials adding a surfactant. These emulsions were burning in a high temperature furnace to produce nickel oxide particles. The mean particle diameter of produced particles was less than 20 nm according to TEM observation. The diameter of the particles was much smaller than the estimated value based on the size distribution of dispersed solution phase in the emulsions and its concentration. Moreover, there is no effect of the concentration of the aqueous solution phase. On the other hand, X-ray diffraction pattern showed that the produced particles were complex of metal nickel with nickel oxide.

In this research a high yield, homogenous and fast bottom-up wet-chemical method has been carried out for the synthesis of platinum nanocrystal (Pt-NC) and up to micron size (Pt-M). After synthesis of the particles, surface plasmon resonance (SPR), ultra violet (UV) spectrum, size, shape, and composition were measured for each set. Platinum nanocrystal attained by preventing particles to grow directly after reduction of Pt+ 4 to Pt0. Pt-NC constructed by statistic repulsion of ionic surfactant surrounded nanocrystals. The final size of the Pt-NC found to be 3. 8 ± 0. 72 nm. Before sonication treatment, particle size of 705. 2 ± 80. 3 nm was achieved. After sonication, particle size increased to 1046. 1 ± 199 nm. Particles were formed in a controllable way, homogenous and mono-disperse in size and shape. It is confirmed that sonication except for the sharpness of the spectrum did not alter the peak wavelengths. The suggested synthesis method enabled cost-effective concrete control over size, shape, concentration, and time of the synthesis.

The present study deals with the preparation of silver (Ag) and iron (Fe) nanoparticles, extracted from AgNO3 and FeSO4 · 7H2O solutions, respectively. For this, the aqueous extract of Erodium cicutarium was used. The Ag and Fe nanoparticles were characterized by several techniques such as X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray (EDX) spectrometer, UV– visible, and Fourier transform infrared (FTIR) spectroscopy. FE-SEM images showed that the Ag and Fe particles had nearly spherical morphology with diameters less than 100 nm. Low amounts of impurity and different chemicals in the prepared nanoparticles were confirmed by EDX spectrometers. Furthermore, different functional groups in the nanoparticles were indicated using FTIR spectrum. Antibacterial activity of the Ag and Fe nanoparticles was evaluated by minimum inhibitory concentration (MIC) for E. coli and S. aureus bacteria. Two parameters such as the concentration of Ag and Fe nanoparticles (X1) and pH (X2) were modeled by the use of the response surface methodology (RSM). These experiments were carried out as a central composite design (CCD) consisting of 13 experiments. The results showed that the concentration of Ag and Fe nanoparticles had a better effect on antibacterial activity. Under optimal conditions— with concentrations of Ag and Fe nanoparticles at 399. 53 and 397. 38 (μ g/mL) and pH values of 8. 20 and 8. 39, respectively— the bacterial growth inhibition halo was found to have the highest diameter.

Direct methanol fuel cell is claiming to be the most main power source in future as a clean energy source, for which methanol is used as fuel. In the present study, nickel nanoparticles were synthesized by green route in the presence of montmorillonite (Ni-MMT). Then the electrochemical activity of prepared nanocomposite was investigated in methanol oxidation reaction in acidic medium. In the process of nickel nanoparticle synthesis, the natural substrate montmorillonite was used as capping agent and Allium jesdianum water extract was used as the source of reducing agent for the first time. The Ni-MMT sample was characterized by UV– Vis, XRD, SEM and EDX techniques. Production of nickel nanoparticles in the proposed green method is confirmed by absorption peak of 405 nm in UV– Vis spectrum. The average particle size of Ni-MMT was determined as 20. 80 nm. The oxidation of methanol in acidic medium was studied by cyclic voltammetry using Ni-MMTmodified carbon paste electrode (Ni-MMT/CPE). Methanol was oxidized on the modified electrode surface at 0. 3 V. Also, the catalytic current of methanol oxidation was 3 mA in H2SO4 electrolyte which is significantly more than unmodified CPE. The concentration of 0. 5 M for H2SO4 was obtained as the optimum electrolyte for the oxidation of methanol. Methanol can be catalyzed in the concentration range of 0. 1– 0. 5 M by the prepared nanostructured catalyst.

The present work is focused on stability of shock wave-exposed copper oxide (CuO) nanoparticles. CuO nanoparticles are synthesized by chemical reduction method and exposed to 100 shock pulses having Mach number 2. 4. The table top semiautomatic pressure-driven shock tube is used to generate shock waves for the present experiment. The influence of shock waves on the treated and untreated CuO nanoparticles are explored and characterized by a variety of properties like structural, molecular and morphological details observed using powder XRD, FTIR and SEM, respectively. The powder XRD profile confirmed that there are no lattice defects or any deformation except negligible changes in grain size. SEM images established that the shock wave-loaded CuO nanoparticles have good structural and morphological stability. The obtained results showed that CuO nanoparticles can be used in aerospace, nuclear reactors and high-pressure applications which undergo extreme conditions. The details are presented intensely in the following sections.

The present work emphasizes the effect of the use of Sn, with different concentrations, over the structural properties and sensing applications of LaCrO3. In this work, LaCrO3 nanostructures were modified with different concentration of Sn (0. 2 M %, 0. 4 M %, 0. 6 M % and 0. 8 M %). Different modified Sn-doped LaCrO3 was synthesized by sol– gel method and followed by preparation of thick films via a conventional screen printing approach. The characterizations done by means of X-ray diffraction (XRD), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the confirmation of a Sn-doped LaCrO3 crystal structure and its morphology, respectively. These oxides were formulated to identify various air pollutants such as CO2, ethanol, H2S, NH3, NO2, and acetone. The Sn-doped LaCrO3 with 0. 4 M % Sn displayed higher gas response to ethanol vapor at the range of 150– 250 ° C. The sensors additionally demonstrated proper recovery and acceptable stability.