Magnesium Aluminate Nanoparticles Research Articles

Bioinspired synthesis of calcium magnesium aluminate nanoparticles using aloe vera extract: A promising material for electrochemical sensors, antibacterial and environmental remediation applications

Aloe vera (Aloe barbadensis miller) leaf extract was used in green fuel-assisted microwave synthesis to prepare Calcium Magnesium Aluminate (CMA). The synthesized CMA was characterized by X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), Scanning electron microscope (SEM), Energy dispersion spectrometer (EDAX), and Transmission Electron Microscopy (TEM) analyses. X-ray diffraction confirmed the formation of Ca2Mg2Al28O46. The UV–Vis diffuse reflectance (DRS) technique was employed to investigate its absorbance spectrum, and the band gap of CMA was found to be 4.9 eV. The CMA nanoparticles were used to design a sensing electrode for creatinine, enabling the determination of its concentration in human samples and heavy metals. Acid Orange-88 dye was degraded using CMA nanoparticles as a photocatalyst under UV irradiation. After dye degradation, treated water was used to grow Vigna radiata plants to test their suitability for seedling growth. This report demonstrates that CMA photocatalysts are alternatives to semiconductor photocatalysts for the degradation of Acid Orange-88 dye under UV illumination. Escherichia coli (E. coli), Staphylococcus species, and Pseudomonas species were used as model organisms to assess the antibacterial activity of CMA NPs through a green route.

Thermal transport of radially magnetized peristalsis of non-Newtonian nanofluid through an asymmetric curved channel

Present examination explores the heat and mass transfer phenomena for magnetohydrodynamics (MHD) peristaltic transport of diethylene glycol (DEG)-based Cross nanofluid through an asymmetric curved channel. The mass and thermal characteristics of nanofluid are established through the assessment of Buongiorno nano-liquid model, which allows to identify intriguing features of thermophoretic and Brownian diffusion coefficients. Further, velocity slip conditions are enforced on the peristaltic walls. The influences of thermal radiation, radius-dependent magnetic field and viscous dissipation are also taken into consideration. The governing equations are simplified by employing lubrication theory (“biological estimate of the creeping transportation phenomenon”), and resulting system is tackled numerically. Impacts of different flow parameters on the nanofluid’s velocity, nanomaterials concentration profile, heat and mass transfer, streamlines, temperature of nanofluid, and stresses at the wall are analyzed via graphs and tables. The findings of this investigation report that nanofluid’s temperature enhances against Hartmann and Brinkman numbers, whereas it declines for the thermal radiation parameter. The distribution of the concentration profile decreases for Brownian motion while it increases for the thermophoresis parameter. Further, a development in the stresses, thermal and mass transfer rates at the boundary is seen for better values of the Hartmann number. Additionally, higher values of the velocity slip parameter show increasing behavior for the velocity of nanofluid near the walls of the channel. The effects of MHD with magnesium aluminate nanoparticles suspended in DEG base fluid-based nanofluid through an asymmetric curved conduit have many uses in industry, organic compounds, biomedical engineering, and commercial productions, such as brake fluid, tobacco, polyester resins, certain dyes, printing ink, polyurethanes, glue, resins, antifreeze, nitrocellulose, oils, cigarettes, plasticizers, and so forth. DEG-based nanofluids are also used in human medications, including acetaminophen and sulfanilamide, which can result in incidents of human poisoning, some of which have been fatal, either intentionally or unintentionally.

Study of mass and heat transfer for peristaltic transport of cross nanofluid through a curved channel

AbstractNanoparticles have significant applications in drug delivery systems, heat exchanges, treatment of several diseases and chemical reactions. The Cross non‐Newtonian nanofluid model for heat and mass transfer inspection with diethylene glycol‐based fluid is highlighted in this study. The magnesium aluminate nanoparticles are used to evaluate nanofluid characteristics. The current investigation explores the numerical results for magnetohydrodynamics (MHD) peristaltic movement of Cross‐nanofluid via a curved channel under the influences of thermal radiation, heat sink/source and Joule heating. The effects of viscous dissipation, thermophoretic, variable thermal conductivity and Brownian diffusion coefficients in the presence of mass and thermal convection are also taken into consideration. Flow problem is modeled using fundamental conservation laws, and the resulting nonlinear partial differential equations (PDEs) are reduced to a system of nonlinear ordinary differential equations (ODEs) by employing long wavelength and a small Reynolds number approximations. Simplified systems of ODEs are addressed by adopting numerical technique via the NDSolve built‐in command in Mathematica. Furthermore, graphical presentations explain the behavior of relevant flow parameters. Results indicate that better values of the magnetic number and the thermophoresis parameter increase the rate of mass transfer. Results indicate that the nanofluid's temperature increases by improving values of the Brinkman number and falls with the thermal radiation parameter. It is also stated that the nanofluid's velocity reduces near the lower wall for greater values of Hartman number. Moreover, heat transfer rate improves for larger values of the heat generation parameter and curvature parameter.

Development of Magnesium Aluminate (MgAl2O4) Nanoparticles for refractory crucible application.

Ceramics are the oxides of metals and nonmetals with excellent compressive strength. Ceramics usually exhibit inert behavior at high temperatures. Magnesium aluminate (MgAl2O4), a member of the ceramic family, possesses a high working temperature up to 2000°C, low thermal conductivity, high strength even at elevated temperatures, and good corrosion resistance. Moreover, Magnesium Aluminate Nanoparticles (MANPs) can be used in the making of refractory crucible applications. This study focuses on the thermal behavior of Magnesium Aluminate Nanoparticles (MANPs) and their application in the making of refractory crucibles. The molten salt method is used to obtain MANPs. The presence of MANPs is seen by XRD peaks ranging from 66° to 67°. The determination of the smallest crystallite size of the sample is achieved by utilizing the Scherrer formula and is found to be 15.3 nm. The SEM micrographs provided further information, indicating an average particle size of 91.2 nm. At 600°C, DSC curves show that only 0.05 W/g heat flows into the material, and the TGA curve shows only 3% weight loss, which is prominent for thermal insulation applications. To investigate the thermal properties, crucibles of pure MANPs and the different compositions of MANPs and pure alumina are prepared. During the sintering, cracks appear on the crucible of pure magnesium aluminate. To explore the reason for crack development, tablets of MgAl2O4 are made and sintered at 1150°C. Ceramography shows the crack-free surfaces of all the tablets. Results confirm the thermal stability of MANPs at high temperatures and their suitability for melting crucible applications.

Efficient Photocatalytic Decomposition of Acid Blue 25 Dye using Facilely Synthesized Magnesium Aluminate Nanoparticles

Efficient Photocatalytic Decomposition of Acid Blue 25 Dye using Facilely Synthesized Magnesium Aluminate Nanoparticles

A Benign Approach for Sunlight and UV Driven Photocatalytic Applications of Green Synthesized Novel Calcium Magnesium Aluminate Nanoparticles for Acid Red-88 Dye Degradation

A Benign Approach for Sunlight and UV Driven Photocatalytic Applications of Green Synthesized Novel Calcium Magnesium Aluminate Nanoparticles for Acid Red-88 Dye Degradation

Low-pressure injection molding of magnesium aluminate nanoparticles: Rheological behavior and flexural properties of sintered component

This research aims to investigate the density and flexural strength of nanostructured spinel parts fabricated using the low-pressure injection molding (LPIM) method. For this purpose, firstly, the effect of the amount of binder was tested on the rheology behavior of the feedstocks containing spinel nanopowder for producing ceramic parts using the LPIM method. The rheometric analysis indicated that the feedstocks containing 80 wt% powder and 20 wt% binders showed shear-thinning fluid behavior and were chosen as the optimal low-viscosity feedstocks for the LPIM process. After binder removal from LPIMed part, secondly, the effect of sintering temperature was examined on the relative density and flexural strength of the spinel parts. The results indicated that by increasing sintering temperature from 1550 °C to 1700 °C, the size of pores was reduced and grain size was increased from 2 μm to 6 μm. Furthermore, the flexural strength of the parts sintered at 1700 °C was 10 MPa greater than that of the sample sintered at 1650 °C.

Triethanolamine assisted sol‐gel approach for obtaining two‐dimensional magnesium aluminate nanosheets

AbstractAqueous‐phase synthetic route was applied for the preparation of magnesium aluminate spinel nanosheets with two‐dimensional nanostructure through a sol‐gel combustion approach, where triethanolamine was employed as a complexing agent and fuel. Results demonstrate that the as‐synthesized two‐dimensional nanosheets are well crystallized and show high purity. The pure magnesium aluminate nanoparticles with an average crystallite size of 25 nanometers were obtained at 1200 °C. Also, the two‐dimensional magnesium aluminate powder contain nanosheets with thicknesses in the 20 nanometers–30 nanometers range, and the lateral size is in the range of ∼10 micrometers–30 micrometers.

Nanoremediation of dimethomorph in water samples using magnesium aluminate nanoparticles

Abstract The present work aims to prepare magnesium aluminate nanoparticles (MgAl2O4 NPs) using aluminum isopropoxide and magnesium ethoxide by hydrolysis reaction and to investigate them as new adsorbent materials for the extraction and clean-up of dimethomorph pesticide from tap water. The MgAl2O4 NPs were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The XRD result confirmed the formation of the spinal cubic structure in the fabricated sample. A solid-phase extraction (SPE) cartridge packed with MgAl2O4 NPs was used to extract dimethomorph pesticide from water samples. The extracted pesticide solution was quantified using a validated liquid chromatography mass spectrometry (LC-MS-MS) method. The limit of quantification (LOQ) was found to be 1 μ g/L, signifying the sensitivity of the LC-MS-MS. The water samples were passed through the cartridges and investigated to find the adsorption strength of the pesticides under the influence of temperature, volume of sample, flow rate, pH and ionic strength on the efficiency of the cartridge. The extraction efficiency of the developed MgAl2O4 NPs SPE was found to be higher than that of commercially available SPE- C 18 cartridge. The average recoveries of the pesticides ranged from 90%–94% which was obtained at two different fortification levels of 1 and 10 μ g/L using MgAl2O4 NPs SPE.

Magnesium Aluminate Nanoparticles for Chemical Detoxification of Sarin and Soman.

The solutions of Mg(NO₃)₂, Al(NO₃)₃, and (NH₄)₂CO₃ were mixed at pH 8 and then heated at 95 °C for 4 h, aged at room temperature for 16 h, and calcined at 650 °C for 4 h to obtain magnesium aluminate nanoparticles. The obtained materials exhibited spinel structure with the particle size being 6 to 26 nm. The nanoparticles demonstrated type IV nitrogen adsorption isotherm, typical of mesoporosity with a surface area of 325 m²/g. They were utilized for studies on chemical detoxification of deadly chemical warfare agents such as sarin and soman. Our results showed that the magnesium aluminate nanoparticles effectively decontaminated more than 99% of sarin and soman within 8-10 min when used at a ratio of 1:50-60% w/w.

Layer by layer nanocomposite filter for ABC filtration

A multifunctional layer by layer nanocomposite air filter was fabricated by using electrospinning method. Polyacrylonitrile (PAN) nanofibers incorporated with silver nanoparticles (Ag NP) acts as first layer and PAN nanofibers incorporated with magnesium aluminate nanoparticles (MA NP) acts as second layer which was placed between polypropylene spun bonded nonwoven (PP SBN). The morphology of the prepared nanocomposite filter was studied by scanning electron microscopy. The performance of the filter was evaluated against i) bacterial filtration efficiency (BFE) with inhibition property ii) PM2.5 aerosol filtration efficiency (AFE) and iii) chemical detoxification efficiency. The developed nanocomposite air filter showed 99% filtration efficiency against bacterial agent & PM2.5 and 95% detoxification against 2-choloro ethyl ethyl sulfide (2-CEES). The result obtained showed that the developed layer by layer nanocomposite filter has the potential application against ABC removal.

Removal of Congo Red dye, polar and non-polar compounds from aqueous solution using magnesium aluminate nanoparticles

Magnesium aluminate nanoparticles were prepared by the sol–gel autocombustion method using mixture of alanine and urea as a fuel. The sample was characterized using XRD, FE-SEM, EDS, and IR spectroscopy. XRD analysis confirmed the formation of single-phase spinel compound with average particle size of 28 nm estimated from FE-SEM analysis. IR spectrum revealed the stretching vibration of MA-O and MB-O bonds at 517 and 691 cm−1 respectively. The adsorption process of Congo Red dye on the spinel surface was studied under static conditions using UV–Vis spectrophotometry. The maximum equilibrium adsorption capacity obtained from the Langmuir model was calculated 24.5 mg∙g−1. In addition, the salicylic acid and mixture of polyaromatic hydrocarbons as polar and nonpolar compounds, respectively, were used to investigate the adsorption properties of MgAl2O4 by liquid chromatography (UFLC) analysis. The results suggest that the magnesium aluminate can be used as efficient adsorbent for anionic dyes and polar compounds due tothe presence of active centers on its surface.

Synthesis of mesoporous metal aluminate nanoparticles and studies on the decontamination of sulfur mustard

Magnesium, calcium, cobalt, nickel, copper, and zinc aluminate nanoparticles were synthesized by co-precipitation method. They were characterized by transmission electron microscopy, X ray diffraction, scanning electron microscopy coupled with energy dispersive analysis of X rays, nitrogen adsorption techniques. Transmission electron microscopy data indicated the formation of mesoporous metal aluminate nanoparticles with particle size ranging from 5 to 100 nm. X ray diffraction data indicated the formation of metal aluminate nanoparticles with spinel structure. Nitrogen adsorption data of metal aluminate nanoparticles illustrated mesoporosity with the values of surface area ranging from 63 to 325 m2/g. These mesoporous metal aluminate nanoparticles were used for decontamination of sulfur mustard and the decontamination reactions exhibited first order behavior. Magnesium aluminate nanoparticles showed greater decontamination efficiency relative to other ones and decontaminated 100% of sulfur mustard within 4 h where others took more time to completely degrade it. The promising decontamination properties of metal aluminates nanoparticles against sulfur mustard were attributed to the basic sites, Lewis acid sites and the presence of these sites was confirmed by CO2 and NH3 temperature programmed desorption.

Preparation and characterization of the magnesium aluminate nanoparticles via a green approach and its photocatalyst application

Pure bismuth aluminate (Bi2Al4O9) nanoparticles were successfully synthesized by novel sol–gel method with the aid of Bi(NO3)3, Al(NO3)3·9H2O, and starch without adding external surfactant, capping agent or template. Moreover, starch plays role as capping agent, reducing agent, and natural template in the synthesis Bi2Al4O9 nanoparticles. The structural, morphological and optical properties of as obtained products were characterized by techniques such X-ray diffraction , energy dispersive X-ray microanalysis, scanning electron microscopy, and ultraviolet–visible spectroscopy. The samples indicated a ferromagnetic behavior, as evidenced by using vibrating sample magnetometer at room temperature. To evaluate the photocatalyst properties of nanocrystalline bismuth aluminate, the photocatalytic degradation of methyl orange under ultraviolet light irradiation was carried out.

Mesoporous MgAl2O4 and MgTiO3 nanoparticles modified polyacrylonitrile nanofibres for 2-chloroethyl ethyl sulfide degradation

Degradation of 2-chloroethyl ethyl sulfide (2-CEES), a stimulant of sulfur mustard, was investigated on the surface of polyacrylonitrile (PAN) nanofibres embedded with magnesium aluminate and magnesium titanate nanoparticles. The magnesium aluminate and magnesium titanate nanoparticles were prepared by the hydrothermal method and characterized by X-ray diffractometry, scanning electron microscopy and nitrogen adsorption BET. These metal oxide nanoparticles were mixed with PAN solution individually and then electrospun to produce nanofibres. Later, they were studied against the degradation of 2-CEES at room temperature (30±2 °C) using gas-chromatography coupled with flame ionization detector. The degradation and reaction kinetics data reveal that the 2-CEES degraded faster with higher amount of embedded metal oxide nanoparticles in PAN nanofibres. Moreover, the degradation yield of 2-CEES was higher in the case of PAN nanofibres embedded with magnesium aluminate nanoparticles relative to PAN nanofibres embedded with magnesium titanate nanoparticles. Fourier-transform infrared (FTIR) studies showed that the PAN nanofibres embedded with magnesium aluminate and magnesium titanate nanoparticles degrade 2-CEES by the formation of covalent/alkoxide bonds between the surface reactive oxide/hydroxyl group of metal oxide nanoparticles and 2-CEES. The result explores the role of modified PAN nanofibres with magnesium aluminate on the effective degradation of 2-CEES and possesses a suitable candidate for protective application.

Synthesis, characterization and ionic conductivity of MgAl2O4

Magnesium aluminate nanoparticles have been synthesized by a citrate sol-gel route. X-ray diffraction and IR spectroscopy study confirmed the formation of MgAl 2 O 4 cubic spinel structure without presence of any secondary phase. Crystallite size of the synthesized nanoparticles was found to be equal to 24 nm. The ac conductivity of MgAl 2 O 4 was studied using complex impedance spectroscopy technique in the frequency range from 5 Hz to 13 MHz and temperature range from 673 to 798 K. The temperature and frequency dependence of ac conductivity were highlighted and the activation energies of, respectively, ac conduction and relaxation processes were also calculated.

Application of autoignition technique for synthesis of magnesium aluminate spinel in nano scale: Influence of starting solution pH on physico-chemical characteristics of particles

The present investigation is a follow-up of studies on glycine-nitrate autoignition technique for production of magnesium aluminate nano-particles. The technical characteristics of powders were studied in relation to a wide range of pH, 2.5–10.5. The effect of pH on particle formation was particularly emphasized to achieve a powder in nano-scale. In preparation of precursors the Mg/Al mole ratio was considered to be 0.50 and the level of fuel/NO3 was adjusted at 0.75. The thermal behavior of precursors was evaluated by DTA-TG technique. Also, the obtained powders were calcined at 600, 800, 1000 and 1200 °C and characterized by XRD, BET, TEM and elemental analysis methods. The results indicated that the physico-chemical characteristics of products are strongly influenced by the pH of synthesis environment. The precursor prepared in pH of 2.5 exhibits flaming type ignition, while the precursors synthesized at neutral and alkali environments show underwent smoldering type combustion. In conclusion, the optimum characteristics were achieved when precursor is manufactured at neutral condition.

A novel synthetic route for magnesium aluminate (MgAl2O4) nanoparticles using sol–gel auto combustion method and their photocatalytic properties

In this paper a novel and inexpensive route for the preparation of spinel magnesium aluminate nanoparticles (MgAl2O4) is proposed. Magnesium aluminate photocatalyst was synthesized via sol–gel auto combustion method using oxalic acid, urea, and citric acid fuels at 350°C. Subsequently, the burnt samples were calcined at different temperatures. The pure spinel MgAl2O4 with average crystallite size 27.7, 14.6 and 15.65nm was obtained at 800°C calcinations using the aforementioned fuels, respectively. The obtained samples were characterized by powder X-ray diffraction, Fourier transform infrared, UV–Vis spectroscopy, transmission electron microscope, scanning electron microscope. The photo catalytic activity of MgAl2O4 product was studied by performing the decomposition of Reactive Red Me 4BL dye under UV illumination or sunlight irradiation. The dye considerably photocatalytically degraded by 90.0% and 95.45% under UV and sunlight irradiation, respectively, within ca. 5h with pseudo first order rate constants of 5.85×10−3 and 8.38×10−3min−1, respectively.

Growth of magnesium aluminate nanocrystallites

Nanocrystalline magnesium aluminate was synthesized with the coprecipitation method. Its growing behaviors as a function of temperature were studied with synchrotron X-ray diffraction (XRD) and Raman spectroscopy. It is found that the particle growth was greatly inhibited at temperatures below 1000 °C due to the hydroxide precursor reactants. Above 1000 °C, magnesium aluminate nanoparticles start to grow fast. After two hours annealing at 1200 °C, the grain size changes by multiple folds, suggesting that oriented attachment may occur. Above 1200 °C, the grain size changes in various directions are much smaller than the average grain size, indicating the oriented attachment mechanisms become inactive in the growth of MgAl2O4 nanoparticles with sizes larger than 42 nm.

Adsorption of methylene blue onto spinel magnesium aluminate nanoparticles: Adsorption isotherms, kinetic and thermodynamic studies

Magnesium aluminate spinel has been synthesized at nanoscale by coprecipitation method. The synthesized material was characterized for the phase composition, quantitative description, surface morphology, surface area, pore volume and pore diameter. X-ray diffraction analysis confirmed the formation of the cubic spinel phase with no peaks corresponding to the impurity phases. The Scherrer crystallite size calculated from line broadening is 20nm. The pore surface area was found to be 343m2/g by N2 vapor adsorption experiments and material was characterized as mesoporous on the basis of pore diameter analysis. The scanning electron micrograph shows the agglomeration of particles while the nanosize is confirmed by the transmission electron micrograph. The porous nature of the material was then explored for carrying out the adsorption of methylene blue solutions onto the surface. Adsorption studies were carried out with 0.1g of the material and the effect of pH and shaking times were studied and both were found to influence the adsorption. Adsorption data was also fitted to Temkin, Freundlich and the Langmuir adsorption models in order to study the mechanism of adsorption by interpreting the calculated parameters like, heat of adsorption (BT), binding energy (KT), degree of adsorption (KF), heterogeneous factor (n), and energy of adsorption (KL), binding forces (aL), and the separation factor (RL). The pseudo-second order rate constant (Kp−2), initial sorption rate (Srate) and the half adsorption time (t1/2) were also calculated and explained to clarify the mechanism of adsorption onto MgAl2O4 surface. Gibbs free energy was also calculated from the adsorption data at room temperature.