Journal of Nanoanalysis
Volume:6 Issue: 1, Sep 2019

In recent years, the use of nanotechnology (nano-particles, nanomaterial, nano-additives and nanostructuredmaterials) has attracted attention of scholars, engineers and scientists in all scientificfields such as chemistry, medicine, material, agriculture, electronic etc. The use of nanotechnologyhas also become widespread in the refractory products (which mainly used in various industries suchas steel, casting, cement, glass etc.). Therefore, the effect of using different types and contents ofnanomaterials (oxides and non-oxides) as well as the control of microstructure has been evaluatedby many researchers on the properties of shapes (bricks) and un-shaped (monolithic) refractoryproducts. The obtained results were very promising and satisfactory. One of the most consumablerefractory products in various industries is monolithic refractories, which has been widely usedbecause of their great benefits to the other refractory products (bricks). In this paper, recent advancesin monolithic refractories by using the finding of nanotechnology are presented. This article can beconsidered as guidance for researchers, students gain easy access to experimental results obtainedby different research group using nanotechnology and nano materials in monolithic refractories.

Perovskite-type oxides of LaFe(1+x)O(3+δ) (x = 0.0, 0.2, 0.5 and 0.7) were synthesized by citrate sol–gel methodto ensure the formation of nanosized perovskites. The physicochemical properties of these LaFe(1+x)O(3+δ)materials were characterized by thermal gravimetric/differential analyses, Fourier transform infraredspectroscopy, X-ray powder diffraction, scanning electron and transmission electron microscopies,ultraviolet-visible spectroscopy, Brunauer Emmett Teller nitrogen absorption, electrical conductivitymeasurements and magnetic studies. Catalytic performances of the prepared materials were evaluatedfor the carbon monoxide oxidation. Trace of FeCO3 and Fe2O3 phases were detected over the perovskitesof LaFe(1+x)O(3+δ) with excess iron (x > 0) using the XRD and FT-IR studies. The SEM results demonstratethe formation of non-spongy particles. The magnetic measurements show a charge ordering transitionat ~230 K for LaFe1.2O(3+δ) perovskite. The weak long range charge ordering of Fe2+/Fe3+ destroys over anincrease in the content of the phases other than LaFeO3 perovskite. The best σox/σRed and the lowest Ecis accounted for the more suitable path for catching and giving of the gas phase oxygen over LaFe1.2O(3+δ)nanoperovskite; meaning most favorable redox properties. The light off temperature of the CO oxidationin terms of reducibility studies is decreased about 70°C over crystalline LaFe1.2O(3+δ) catalyst.

The potential of nanofluids for the improvement of heat transfer coefficient in various heat exchangeequipment has been considered and studied as a major application during recent decades. In this research,heat transfer coefficient of ZnO, TiO2 and ZnO/TiO2 nanofluids in a shell and tube heat exchanger has beenstudied experimentally. ZnO nanoparticle was synthesized through precipitation technique. Sol-gel andmechanical techniques were employed to synthesize the ZnO/TiO2 nano-composite. Particle size analysis(PSA), XRD, FTIR and FE-SEM techniques were used to characterize ZnO/TiO2 nano-composite. Based onthe results, the nanofluid heat transfer coefficient was enhanced by increasing the nanofluid concentrationand temperature. The heat transfer coefficient of TiO2 was higher than that of ZnO nanofluid and the heattransfer coefficients of nano-composites were higher than that of ZnO and TiO2 nanofluids and the basefluid. Also, the heat transfer coefficient and the overall heat transfer coefficient were increased 3.79 to9.09 times and 4.27 to 9.14, respectively by increasing the nano-composite content.

In this study the interaction of cis-PtCl2(NH3)2 complex and graphene were investigated with MPW1PW91method in gas and solvent phases. The solvent effect was examined by the self-consistent reaction fieldtheory (SCRF) based on Polarizable Continuum Model (PCM). The selected solvents were chloroform,chlorobenzene, bromoethane, dimethyldisulfide, and dichloroethane. The solvent effect on thefrontier orbital energy and HOMO-LUMO gap were studied. The characterization of the interactionbetween two fragments was clarified with energy decomposition analysis (EDA). Pt-C(Graphene) andH(NH3)...C(Garaphen) interactions in the graphene … cis-PtCl2(NH3)2 complex were analyzed usingquantum theory of atoms in molecules analysis (QTAIM).

Three surfactants were selected to modify glassy carbon electrode including sodiumdodecylbenzenesulfonate, Tween 80 and cetyltrimethylammonium bromide. The obtained nano-Au/surfactant/GCEs were characterized with scanning electron microscopy and electrochemicaltechniques. Electrochemical behavior of catechol at the nano-Au/surfactant/GCE was thoroughlyinvestigated for modified electrodes. Compared to the unmodified electrode, the peak currentobviously increased and the oxidation and reduction peaks potential shifted to the negative andpositive potential area, respectively, meaning the peak potential separation is reduced. Thesechanges indicated that the composite nanoparticles possess good electrocatalytic performance onthe electrochemical reaction of catechol. The experimental results revealed that the nanoparticlemodified electrodes have good performances for catechol sensing, which including convenientfabrication, low detection limits and wide linear ranges. These merits of this sensing system providehigh potential to apply in environmental monitoring. In addition, kinetic parameters of catecholredox reaction were determined and the number of electrons was obtained two for the threemodified electrodes.

This study aimed to investigate the adsorption of CH4, CO2, H2S at a temperature of 298.15 K and pressurerange of 0.1 to 30 atm, and compare the results with experimental data for MIL-47 using GCMC. Themaximum CH4, CO2 and H2S adsorptions were 3.6, 10.45, and 12.57 mol.kg-1, respectively. In addition, theselectivity for binary mixtures of CH4/CO2 and CH4/H2S was calculated. The results for CH4/CO2 mixturesat 10 atm showed that: 1) MIL-47 only adsorbed CO2 in a 0.05 CH4/ 0.95 CO2 mixture, and 2) by increasingthe mole fraction of CH4, the selectivity toward CO2 decreased. The results for H2S/CH4 mixture at 10atm showed that: 1) H2S was adsorbed only in mole fractions of 0.95, 0.75, and 0.50 of H2S, and 2)the observed selectivity was about 132.7 and 63.2 at H2S mole fractions of 0.25 and 0.05, respectively.The MD simulations and RDF analyses were used to investigate 0.5 CH4/0.5 CO2 and 0.75 CH4/0.25 H2Smixtures. The results showed that the adsorption mostly occurs on the metallic part of MIL-47. Wefound that V and O atoms were the active adsorption sites in MIL-47. H2S and CH4 showed to have thehighest and lowest levels of self-diffusions, respectively. The MD simulations were used to study the selfdiffusionfor mixtures across all mole fractions. In the binary mixture of 0.95 CO2/0.05 CH4, the maximumself-diffusion was 1.49×10-12 m2s-1 for CO2. The maximum self-diffusion for H2S in the mixture of 0.05CH4/0.95 H2S was 2.62×10-10 m2s-1.

Density functional theory calculations were carried out to investigate the structural and electronicproperties of the adsorption of O3 molecules on AlP-codoped monolayers to fully exploit the gas sensingcapability of these two-dimensional materials. Various adsorption sites of O3 molecule on the considerednanosheets were examined in detail. The side oxygen atoms of the O3 molecule strongly bind to the tinatoms, and provide double contacting point between the nanosheet and O3 molecule. O3 adsorptionon the Al-site of AlP-codoped structure is more favorable in energy than that on the pristine one. AlPcodopedstanene exhibits better semiconductor characteristics because of the band gap opening in thesystem. The total electron density plots show the charge distribution along the interacting side oxygenand tin atoms, which indicate the formation of chemical bonds between them. This formation of chemicalbond was also evidenced by the projected density of states diagrams. The large overlaps between thePDOS spectra of the oxygen and tin atoms show the formation of chemical bonds between these atoms.The charge density difference calculations represent charge accumulation on the adsorbed O3 molecule.Our results suggest a theoretical basis for AlP-codoped stanene monolayer as efficient candidate forapplication in gas sensor devices.

In recent years, there is a lot of interest in synthesis of nanostructures as carriers for drug delivery.These structures are considered as a highly effective drug delivery system due to controlling drugrelease, protecting the pharmaceutical molecule, and environmentally friendly. In this study, thesynthesis of chitosan nanoparticles was carried out by chemical method. The nanoparticles size wasmeasured by dynamic light scattering (DLS). Also, it was used from atomic absorption spectrometry(AAS), FTIR and transmission electron microscopy (TEM) to confirm the loading of antibiotic ontonanoparticles and to calculate the percentage of the drug loaded. In addition, it was used forclarithromycin as antibiotic. The antibacterial activity was studied by the disc-diffusion methodand the effect of different concentrations of the drug in nano-carriers were investigated and it wasdetermined the optimum antibacterial activity of drug nanocarrier was happened in concentration0.6 gr/10 ml.