scholarly journals Influence of ZrO2 Nanoparticles on the Microstructural Development of Cement Mortars with Limestone Aggregates

2019 ◽  
Vol 9 (3) ◽  
pp. 598
Author(s):  
Danna Trejo-Arroyo ◽  
Karen Acosta ◽  
Julio Cruz ◽  
Ana Valenzuela-Muñiz ◽  
Ricardo Vega-Azamar ◽  
...  
Keyword(s):  
Xrd Analysis ◽  
Sem Analysis ◽  
Precipitation Method ◽  
Zro2 Nanoparticles ◽  
Microstructural Development ◽  
Cement Ratio ◽  
Cement Mortars ◽  
Crystallite Sizes ◽  
Co Precipitation ◽  
Two Stages

In this research, the effect of the addition of zirconium oxide-synthesized nanoparticles on the microstructural development and the physical–mechanical properties of cement mortars with limestone aggregates was studied. Zirconia nanoparticles were synthesized using the co-precipitation method. According to XRD analysis, a mixture of tetragonal (t) and monoclinic (m) zirconia phases was obtained, with average crystallite sizes around 15.18 and 17.79 nm, respectively. Based on the ASTM standards, a mixture design was obtained for a coating mortar with a final sand/cement ratio of 1:2.78 and a water/cement ratio of 0.58. Control mortars and mortars with ZrO2 additions were analyzed for two stages of curing of the mortar—7 and 28 days. According to SEM analysis, mortars with ZrO2 revealed a microstructure with a high compaction degree and an increase in compressive strength of 9% on the control mortars. Due to the aggregates’ characteristics, adherence with the cement paste in the interface zone was increased. It is suggested that the reinforcing effect of ZrO2 on the mortars was caused by the effect of nucleation sites in the main phase C–S–H and the inhibition of the growth of large CH crystals, and the filler effect generated by the nanometric size of the particles. This produced a greater compaction volume, suggesting that faults are probably originated in the aggregates.

Anomalous Behavior of Chemically Synthesized Magnetoplumbite Strontium Ferrite Nano Particles

2012 ◽  
Vol 510-511 ◽  
pp. 330-334 ◽  
Author(s):  
G. Asghar ◽  
S. Nasir ◽  
M.S. Awan ◽  
G.H. Tariq ◽  
M. Anis-ur-Rehman
Keyword(s):  
Dielectric Loss ◽  
Permanent Magnets ◽  
Xrd Analysis ◽  
Anomalous Behavior ◽  
Nano Particles ◽  
Precipitation Method ◽  
X Ray ◽  
Crystallite Sizes ◽  
Co Precipitation ◽  
New Applications

Strontium hexa-ferrite nanoparticles were prepared successfully by simple co-precipitation method. The XRD analysis confirmed the formation of single phase MFe12O19(M=Sr). Parameters such as crystallite size, lattice constant, X-ray density and porosity were calculated from the X-ray diffraction data. The crystallite sizes were in the range 12-26 nm. The temperature dependent dc electrical resistivity measurements showed that the material was highly. Dielectric constant and dielectric loss factor (tanδ) were measured in the frequency range 20Hz-3MHz. The anomalous behavior of dielectric loss revealed a very important behavior of the prepared sample of SrFe12O19in different frequency regions and that could be used for new applications of this material. The magnetic properties were determined from the hystersis loop obtained from vibrating sample magnetometer (VSM). The Curie temperature was determined by susceptometer. This material is potentially suitable for use as a recording medium in identification cards and credit cards and for the fabrication of permanent magnets.

The synthesis of Ba2+-doped multiferroic BiFeO3 nanoparticles using co-precipitation method in the presence of various surfactants and the investigation of structural and magnetic features

2017 ◽  
Vol 31 (15) ◽  
pp. 1750169 ◽  
Author(s):  
Reza Mardani
Keyword(s):  
Magnetic Properties ◽  
Bismuth Ferrite ◽  
Sodium Dodecyl ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Precipitation Method ◽  
Ferrite Structure ◽  
Vibration Sample Magnetometry ◽  
Size Of Particles ◽  
Co Precipitation

In this paper, doped bismuth ferrite nanoparticles with barium (Bi[Formula: see text]Ba[Formula: see text]FeO[Formula: see text], [Formula: see text] = 0.1, 0.15, 0.2) were synthesized by co-precipitation method in the presence of various surface activators. Structural properties, magnetic properties and the size of synthesized nanoparticles were investigated by different techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), dynamic light scattering (DLS) and vibration sample magnetometry (VSM). The data obtained from XRD analysis showed a phase shift from rhombohedral to tetragonal structure by the enhancement of Barium amount in Bismuth ferrite structure. The results of TEM exhibit that the size of particles are 10 nm in average for the synthesized Bi[Formula: see text]Ba[Formula: see text]FeO[Formula: see text] and SEM analysis clarifies the uniform shape of particles which confirms the benign purity of the obtained material. VSM analysis shows that the best magnetic function will be observed when stoichiometric amount of Barium (Bi[Formula: see text]Ba[Formula: see text]FeO[Formula: see text] is [Formula: see text] = 0.15. The effect of diverse surface activators including Triton X-100, polyvinyl alcohol (PVA), sodium dodecyl sulfate (SDS), and cetyl trimethylammonium bromide (CTAB) was studied in the synthesis of Bi[Formula: see text]Ba[Formula: see text]FeO[Formula: see text] nanoparticles and CTAB presented the best effect on the magnetic properties of these nanoparticles.

Upshot of Concentration of Zirconium (IV) Oxynitrate Hexa Hydrate on Preparation and Analyses of Zirconium Oxide (ZrO2) Nanoparticles by Modified Co-Precipitation Method

2021 ◽  
Vol 21 (11) ◽  
pp. 5707-5713
Author(s):  
M. Ramachandran ◽  
R. Subadevi ◽  
P. Rajkumar ◽  
R. Muthupradeepa ◽  
R. Yuvakkumar ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Raw Material ◽  
Precipitation Method ◽  
Zro2 Nanoparticles ◽  
Fixed Amount ◽  
Complex Impedance Analysis ◽  
Dta Analysis ◽  
Co Precipitation

In the present work, pure nanocrystalline monoclinic Zirconia (ZrO2) has been successfully synthesized and optimized by the modified co-precipitation method. The concentration of raw material has been optimized with the fixed amount of precipitation agent (Potassium hydroxide KOH). The thermal history of the precursor has been examined through TG/DTA analysis. All the samples are subjected to study the structure, fingerprints of the molecular vibrations, and morphology analyses. The representative sample has been analyzed through Transmission Electron Microscope (TEM) and X-ray Photo Electron Spectroscopy (XPS) analyses. The as-prepared sample exhibits the better crystallinity and surface morphology with lesser particle size (190 nm) when the raw material concentration is 0.2 M. The as-prepared ZrO2 filler (0, 3, 6, 9, and 12 wt.%) is spread through the enhanced polymer electrolyte P(S-MMA) (27 Wt.%)-LiClO4 (8 wt.%)-EC + PC (1;1 of 65 wt.%) complex system via solution casting method. The as-synthesized electrolyte films are examined via complex impedance analysis. P(S-MMA) (27 wt.%)-LiCIO4 (8 wt.%)-EC + PC (1 ;1 of 65 wt.%)-6 wt.% of ZrO2 shows the high ionic conductivity 2.35 × 10–3 Scm–1. Temperature-dependent ionic conductivity studies obey the non-linear behavior. The enhanced ZrO2 has been expected to enhance the other electrochemical properties of the lithium secondary battery.

Synthesis of Magnesia Powder from East Java Dolomite through Leaching, Precipitation and Calcination

2015 ◽  
Vol 1112 ◽  
pp. 550-554
Author(s):  
M. Zaki Mubarok ◽  
Christian Adi Kurniawan
Keyword(s):  
Particle Diameter ◽  
Acid Leaching ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Leach Solution ◽  
Water Removal ◽  
Solution Ph ◽  
Crystal Water ◽  
Lower Temperature ◽  
Co Precipitation

At the present paper, a process of magnesia (MgO) synthesis from East Java dolomite through hydrochloride acid leaching, precipitation and calcination as well as characteristic of the product is discussed. Results of the experimental works show that the dissolution rate of magnesium and calcium from dolomite in hydrochloride acid solution was very rapid. Complete magnesium extraction was obtained by the leaching test with acid concentration of 1.5 molar, particle size distribution of -325#, solid-liquid ratio 1:20 (g/mL), stirring speed 200 rpm at room temperature after only 10 seconds. Precipitation of Mg(OH)2 by the addition of 20% (v/v) CaO slurry into pregnant leach solution resulted in 97.5% Mg precipitation after 1 minute. Solution pH must be maintained at a level of 10-10.5 by adjusting CaO addition in order to minimize calcium co-precipitation and to obtain high purity of Mg(OH)2 precipitate. Calcinations of Mg(OH)2 were performed at temperature range of 550-800°C in which 99% of crystal water removal took place after 5 minute at temperature of 800°C. Lower temperature requires longer time of crystalline water removal from Mg(OH)2. XRF analysis showed MgO purity of 88% with the main impurities of calcium and chloride. XRD analysis detected the presences of calcium as calcite (CaCO3) and portlandite (Ca(OH)2) as impurities in the MgO product. SEM analysis of the MgO powder revealed a nano size of MgO with particle diameter of about 50 nm.

Characterization of Mn0.67Zn0.33Fe2O4 Nanoparticles Synthesized under Different pH

2017 ◽  
Vol 899 ◽  
pp. 48-53
Author(s):  
Rodrigo Uchida Ichikawa ◽  
Walter Kenji Yoshito ◽  
Margarida Juri Saeki ◽  
Willian C.A. Maranhão ◽  
Fátima Goulart ◽  
...  
Keyword(s):  
Profile Analysis ◽  
Rietveld Method ◽  
Spinel Phase ◽  
Sem Analysis ◽  
Line Profile Analysis ◽  
X Ray ◽  
Cell Parameters ◽  
Zn Ferrite ◽  
Crystallite Sizes ◽  
Co Precipitation

Nanostructured Mn-Zn ferrites were synthesized using co-precipitation in alkaline solution with different pH. The samples were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), thermal analysis (TG-DTA), dynamic light scattering (DLS) and scanning electron microscopy (SEM) techniques. Monophasic nanoparticles were formed when synthesized with pH 10.5. This sample was heat-treated and its XRD data was refined by the Rietveld method. Mean crystallite sizes and microstrains were determined from X-ray line profile analysis using Single-Line and Warren-Averbach methods, which revealed a mean crystallite size of approximately 10 nm and negligible microstrains. Zn content was estimated using refined cell parameters, giving a value of 33 at %, in accordance with XRF result. TG-DTA revealed that the incorporation of α-Fe2O3 occurs around 1130 °C and 1200 °C with recrystallization of the Mn-Zn ferrite spinel phase. DLS showed that mean particle size increase with temperature up to 1159 nm at 800 °C. SEM analysis showed the samples agglomerate and present similar morphology with negligible size changing when calcined between 280 °C and 800 °C. However, the sample calcined at 1200 °C presents larger agglomerates due to the sintering process.

Synthesis of Uniform Barium Ferrite Powders by Co-Precipitation Method

2017 ◽  
Vol 898 ◽  
pp. 1649-1654 ◽  
Author(s):  
Min Chen ◽  
Run Hua Fan ◽  
Zi Dong Zhang ◽  
Yan Sheng Yin ◽  
Li Hua Dong
Keyword(s):  
Calcination Temperature ◽  
Barium Ferrite ◽  
Water Bath ◽  
Precipitation Method ◽  
Ammonium Bromide ◽  
Barium Ferrites ◽  
Hexagonal Barium Ferrite ◽  
Crystallite Sizes ◽  
Co Precipitation ◽  
Hexadecyltrimethyl Ammonium Bromide

The uniform hexagonal barium ferrite powders were synthesized by co-precipitation method using metal chloride. The effects of the amount of hexadecyltrimethyl ammonium bromide (CTAB), the water bath and calcination temperature on the phase formation, microstructure and density of barium ferrites were systematically investigated. The results showed that the formation of uniform hexagonal barium ferrite powders was significantly influenced by the amount of CTAB and the water bath could lead to the larger grain size and density. The SEM demonstrated that the BaFe12O19 powders had plate-like shape with crystallite sizes varing from 150 to 200 nm. When the amount of CTAB was 0.2g/100ml and the calcination temperature was 850 °C, the barium ferrite powders were uniform which indicated that the amount of surfactant and calcination temperature were very optimum.

Synthesis and Electrochemical Properties of 0.5Li2MnO3•0.5LiMn0.5Ni0.5O2

2010 ◽  
Vol 105-106 ◽  
pp. 664-667
Author(s):  
Sheng Wen Zhong ◽  
Wei Hu ◽  
Qian Zhang
Keyword(s):  
Cathode Material ◽  
Electrochemical Properties ◽  
Specific Capacity ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Discharge Specific Capacity ◽  
Xrd Patterns ◽  
Co Precipitation ◽  
Two Stages ◽  
Calcined Temperature

The precursor of Mn0.75Ni0.25CO3 is prepared by carbonate co-precipitation method. And the cathode material 0.5Li2MnO3•0.5LiMn0.5Ni0.5O2 is synthesized with two stages calcining temperatures T1 and T2. T1 represents 400°C, 500°C, 600°C and T2 is selected at 750°C, 850°C, 950°C respectively. XRD Patterns shows that the cathode material has the integrated structures of Li2MnO3 and LiMO2, and it has better crystallization during the rise of calcined temperature at 950°C. The electrochemical performances tests indicates that the initial discharge specific capacity are greater than 220mAh/g at the current density 0.2 mA/cm2 in 2.5-4.6V at room temperature. When cathode material is calcined at 750°C, its discharge specific capacity even reach to 248mAh/g, but the cathode material has more perfect general electrochemical properties during calcined temperature at 950°C.

Synthesis, Structural Analysis of Cadmium Sulphide Nanocrystallites

2019 ◽  
Vol 969 ◽  
pp. 169-174
Author(s):  
R. Sivanand ◽  
S. Chellammal ◽  
S. Manivannan
Keyword(s):  
Size Variation ◽  
Cadmium Sulphide ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Precipitation Method ◽  
Capping Agent ◽  
Energy Dispersive Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In this paper, the effect of size variation of cadmium sulphide nanocrystallites which have been prepared by precipitation method is analyzed. These prepared samples were studied using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Energy dispersive analysis of spectroscopy (EDAX) techniques. SEM analysis represents the morphological nature of prepared samples and EDAX indicates the confirmation of elements present in the sample. XRD analysis determines the size of the samples and identifies the structure using miller indices (h k l values) of the nanocrystallies matches with JCPDS. From the XRD analysis, the size variation which depends on dopant, capping agent are discussed and corresponding results are reported in this paper.

The Preparation and Characterization of LiFe0.98Mn0.02PO4/C by Spray-Drying and Low Temperature Reduction Route

2012 ◽  
Vol 581-582 ◽  
pp. 525-528
Author(s):  
Jia Feng Zhang ◽  
Bao Zhang ◽  
Xue Yi Guo ◽  
He Zhang Chen ◽  
Jian Long Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Spray Drying ◽  
Xrd Analysis ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Temperature Reduction ◽  
Co Precipitation ◽  
Low Temperature Reduction

The LiFe0.98Mn0.02PO4/C was synthesized by spray-drying and low temperature reduction route using FePO4•2H2O as precursor, which was prepared by a simple co-precipitation method. The LiFe0.98Mn0.02PO4/C sample was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical measurements. The XRD analysis and SEM images show that sample has the good ordered structure and spherical particle. The charge-discharge tests demonstrate that the powder has the better electrochemical properties, with an initial discharge capacity of 162.1 mAh•g−1 and 155.8 mAh•g−1 at current density of 0.1 C and 1C, respectively. The capacity retention reaches 99.4% after 100 cycles at 1C.

scholarly journals Synthesis of nanocomposite coating based on TiO2/ZnAl layer double hydroxides

2017 ◽  
Vol 67 (325) ◽  
pp. 112 ◽  
Author(s):  
V. Jovanov ◽  
O. Rudic ◽  
J. Ranogajec ◽  
E. Fidanchevska
Keyword(s):  
Mechanical Activation ◽  
Catalyst Support ◽  
Xrd Analysis ◽  
Nanocomposite Coating ◽  
Precipitation Method ◽  
Cleaning Efficiency ◽  
Co Precipitation ◽  
Layer Double Hydroxides ◽  
Double Hydroxides ◽  
Water Rinsing

The aim of this investigation was the synthesis of nanocomposite coatings based on Zn-Al layered double hydroxides (Zn-Al LDH) and TiO2. The Zn-Al LDH material, which acted as the catalyst support of the active TiO2 component (in the content of 3 and 10 wt. %), was synthesized by a low super saturation co-precipitation method. The interaction between the Zn-Al LDH and the active TiO2 component was accomplished by using vacuum evaporation prior to the mechanical activation and only by mechanical activation. The final suspension based on Zn-Al LDH and 10wt. % TiO2, impregnated only by mechanical activation, showed the optimal characteristics from the aspect of particle size distribution and XRD analysis. These properties had a positive effect on the functional properties of the coatings (photocatalytic activity and self-cleaning efficiency) after the water rinsing procedure.

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