45 research outputs found

    The Effect of ZnO Addition on Microstructure, Phase and Color Developments of Copper Reduction Glaze

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    In this research, the effects of Zn on microstructure and color developments of the copper reduction glaze were investigated. Structural and colorimetric characteristics of the glaze surface are examined by X-ray diffraction, scanning electron microscope (SEM) equipped with electron dispersive spectroscopy (EDS) and Telespectrophotometery. Results indicate in samples consisted of more than 7 % of zinc amount, crystalline structures containing Willemite and synthesized copper. XRD indicate that, 14 wt% of zinc oxide is enough to form Willemite. In all samples, duration of process was sufficient to form the metallic particles. SEM images confirm presence of copper nanosphere-laths of Willemite and surrounding glaze

    Influence of grain phase on microstructure and corrosion of low cement castable refractories

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    Available from British Library Document Supply Centre-DSC:DXN049031 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

    Duplex Mechanism of TiC Formation and Ti Dissolution Behavior in KCl-LiCl Molten Salt

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    In the present investigation, an attempt was made to evaluate the dissolution behavior of Ti in molten KCl-LiCl. The X-ray diffraction (XRD) pattern of heated Ti plate at 800 oC for 4 h without carbon black in molten salt revealed that TiCl3 formation was feasible. For more assurance, Ti plate was heated at 950 oC for 4 h in the presence of carbon black to identify synthesized TiC. Transmission electron microscope (TEM) and scanning electron microscope (SEM) images from precursors and the final product showed that nano-crystalline TiC formation from coarse Ti particles was almost impossible without Ti dissolution. Thermodynamics calculations using Factsage software proved that it was possible to form various TiClx compounds. The TiC formation mechanism can be discussed in two possible ways: a reaction between Ti ion and carbon black for synthesizing TiC (direct) and a reaction between TiCl4 and carbon black led to indirect TiC synthesis. Elemental mapping using energy dispersive X-ray spectroscope (EDS) indicated that up to 815 oC, chlorine existed in the map

    Synthesis of Nanostructured Anatase Mesoporous Membranes with Photocatalytic and Separation Capabilities for Water Ultrafiltration Process

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    In this work, the nanostructured anatase mesoporous membranes were prepared for water ultrafiltration (UF) process with photocatalytic and physical separation capabilities. A macroporous substrate was synthesized from α-Al2O3, then a colloidal titania sol was used for the preparation of the intermediate layer. Also, the membrane top layer was synthesized by deposition and calcination of titania polymeric sol on the intermediate layer. The characterization was performed by DLS, TG-DTA, XRD, BET, FESEM, TEM, and AFM techniques. Also, the filtration experiments were carried out based on separation of methyl orange from aqueous solution by a membrane setup with a dead-end filtration cell. Photocatalytic activity of the membranes was evaluated by methyl orange photodegradation using UV-visible spectrophotometer. The mean particle size of the colloidal and polymeric sols was 14 and 1.5 nm, respectively. The anatase membranes exhibited homogeneity, with the surface area of 32.8 m2/g, the mean pore size of 8.17 nm, and the crystallite size of 9.6 nm. The methyl orange removal efficiency by the mesoporous membrane based on physical separation was determined to be 52% that was improved up to 83% by a coupling photocatalytic technique. Thus, the UF membrane showed a high potential due to its multifunctional capability for water purification applications

    The Effect of ZnO Addition on Microstructure, Phase and Color Developments of Copper Reduction Glaze

    No full text
    In this research, the effects of Zn on microstructure and color developments of the copper reduction glaze were investigated. Structural and colorimetric characteristics of the glaze surface are examined by X-ray diffraction, scanning electron microscope (SEM) equipped with electron dispersive spectroscopy (EDS) and Telespectrophotometery. Results indicate in samples consisted of more than 7 % of zinc amount, crystalline structures containing Willemite and synthesized copper. XRD indicate that, 14 wt% of zinc oxide is enough to form Willemite. In all samples, duration of process was sufficient to form the metallic particles. SEM images confirm presence of copper nanosphere-laths of Willemite and surrounding glaze

    EFFECT OF A FOURTH COMPONENT (Na2O, SrO, MgO AND BaO) ADDITION TO CaO-Al2O3-SiO2 SYNTHETIC SLAG ON SULFUR REMOVAL FROM PLAIN CARBON STEEL

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    In this paper, the effect of MgO, BaO, Na 2 O and SrO addition to a pre-melted CaO-Al2O3 -Si 2 O synthetic slag on sulfur removal from plain carbon steel was studied under the same experimental conditions. The slags were pre-melted at 1400°C in an electric resistant furnace and desulfurization experiments were carried out in a high frequency induction furnace. The results showed that the optimum reaction time for desulfurization was 15 min. It was found that while SrO addition to the ternary slag enhances the sulfur removal capability, MgO, Na 2O and BaO additions reduce desulfurization efficiency of the ternary slag. Moreover, it was observed that restricting access to oxygen from the atmosphere by using a covered crucible, could increase desulfurization efficiency of the slag by more than two fol

    Ultrasonic–Assisted Co–Precipitation Method of Preparation of Nanocomposites in The Al2O3–TiO2–ZrO2 System: Characterization and Microsturcture

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    Recently, the Al2O3–TiO2–ZrO2 system has found valuable applications, particularly, as a support for NOx storage–reduction (NSR) catalysts. Nanocomposite powders were prepared from the co-precipitation method in inorganic precursors. The behaviors of mixed oxide nanoparticles under ultrasonic irradiation, such as dispersion, and crushing were studied. Phase transformations, crystallite size, and microstructure of the mixed oxides were investigated by STA (DTA/TG), FTIR, XRD, and SEM. XRD studies showed that zirconium titanate (ZT) is main phase, and the crystallite size varies with the final calcination temperature, and ultrasonic irradiations. SEM observations revealed that the calcination temperature strongly influences the morphology of prepared mixed oxides. The results showed that the inorganic nanoparticles in the aqueous solution can be redispersed more effectively by ultrasonic irradiation than by conventional stirring. The average crystallite sizes of the ZT particles heat treated at 1200 °C for 2 h were in the range of 47-85 nm

    Enhanced densification and ionic conductivity of LLZO by flash sintering

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    Flash sintering arouses the interest since high-density ceramics can be obtained at shorter dwell times and lower temperatures than conventional sintering. In this study, the cubic garnet Li6.25Al0.25La3Zr2O12 (Al-LLZO) was successfully synthesised by the solid-state method. The powders were uniaxially pressed and were subjected to flash sintering at 850°C in a tube furnace under a DC bias using various current densities. It is evidenced that control of the flash electric current is a crucial factor for densification of Al-LLZO. The sample sintered in 50 V cm−1 and 200 mA mm−2 showed a cubic LLZO, 94 ± 0.4% relative density, 0.37 mS cm−1 total ionic conductivity and 0.32 eV activation energy. In addition, it was demonstrated that increasing the current density had a considerable impact on the relative density. This outstanding ionic conductivity might be due to the lower lithium loss and higher density as a result of flash sintering method applied.</p

    Effect of Chemical Composition on Microstructure and Hydrophobic Properties of SiO2-TiO2@PDMS Coating

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    We report a simple and practical approach for the easy production of superhydrophobic coatings based on TiO2-SiO2@PDMS. In this study, we used tetraethylorthosilicate (TEOS) and titanium tetraisopropoxide (TTIP) as a precursor for the sol-gel synthesis of SiO2 and TiO2, respectively. Afterward, the surface of nanoparticles was modified by 1,1,1,3,3,3-hexamethyldisilazane (HMDS) before being combined with polydimethylsiloxane (PDMS). The hydrophobic property of coatings was evaluated by static contact angle measurements. The phase composition and structural evolution of the coatings were examined by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis. It was shown that changing the weight ratio of the solution composition of the coating can affect the hydrophobicity of the surface. The best sample has shown a superhydrophobic property with a 153Ëš contact angle which contained (75%TiO2-25%SiO2) and PDMS at a weight ratio of 1:1. Moreover, the results showed that the superhydrophobic coating retains its hydrophobic properties up to a temperature of 450 ËšC, and at higher temperatures, it converts to a super hydrophilic with a water contact angle close to 0 Ëš. The SiO2-TiO2@PDMS coating degrades methylene blue by about 55% and was shown to be capable of photocatalytically decomposing organic pollutants
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