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.

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.

scholarly journals Photocatalytic degradation of reactive black 5 on the surface of tin oxide microrods

2018 ◽  
Vol 16 (5) ◽  
pp. 773-781 ◽  
Author(s):  
Shanza Rauf Khan ◽  
Muhammad Umar Khalid ◽  
Saba Jamil ◽  
Songnan Li ◽  
Aiman Mujahid ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Tin Oxide ◽  
Degradation Kinetics ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Reactive Black 5 ◽  
Unit Cells ◽  
High Concentrations ◽  
Co Precipitation ◽  
Kinetics Of

Abstract A simple co-precipitation technique is proposed for synthesis of tin oxide (SnO2) microrods. Stannous chloride and urea were used during synthesis. X-ray powder diffraction (XRD) analysis revealed that the annealed product consists of SnO2 microrods having tetragonal unit cells, while scanning electron microscopy (SEM) analysis revealed the rod-like morphology of a synthesized product. These synthesized microrods are used as photocatalyst for the degradation of reactive black 5 (RB5). Degradation kinetics of RB5 are monitored under daylight in different concentrations of hydrogen peroxide (H2O2) and catalyst. The percentage of RB5 conversion is also calculated at various concentrations of hydrogen peroxide and catalyst which demonstrate that RB5 shows high catalytic degradation at high concentrations of hydrogen peroxide and catalyst.

The Effect of Sound on Diamond Hot Filament Chemical Vapor Deposition

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Syed Md. Ihsanul Karim ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Md. Maksud Helali
Keyword(s):  
Chemical Vapor Deposition ◽  
Deposition Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Extra Energy ◽  
Temperature And Pressure ◽  
Lower Temperature ◽  
Hot Filament

This paper presents how vapor deposited coating of carbon (partially diamond) on stainless steel 304 substrate was affected by temperature, pressure and duration of deposition in conjunction with sound vibration. To do so a hot filament chemical vapor deposition apparatus was designed and fabricated. The experiments were carried out under different frequency of vibration (ranging from sonic and ultra sonic). Results show that deposition rate varies with temperature, pressure and duration under vibrating and non-vibrating conditions. It was found that the deposition rate was higher for vibrating condition than that of non-vibrating condition. In this study, the higher the temperature, pressure and duration, the higher the effectiveness of frequency of vibration on the deposition rate was obtained. During thermal CVD process, activation of reactive species was enhanced by chemical activity with the increase of temperature and pressure. By adding extra energy of sound, kinetic energy was increased more due to increase of the adsorption and diffusion rate, which causes the increase of deposition rate.A coating of carbon (partially diamond) has been deposited on the substrate, and the characterization of the coating has been done by SEM including EDX and XRD. The coating of carbon was identified by EDX, and the allotropic forms of graphite and diamond peaks of carbon are found by XRD analysis. SEM analysis shown that the microstructures of deposited coatings were more compact and smoother under higher temperature and pressure than that of lower temperature and pressure.The experimental results are compared with those available in the literature and physical explanations are provided.

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.

Preparation and Characteristics of FePO4·xH2O Powder

2011 ◽  
Vol 675-677 ◽  
pp. 77-80 ◽  
Author(s):  
Hai Li Jing ◽  
Guo Jun Li ◽  
Rui Ming Ren
Keyword(s):  
Electron Microscopy ◽  
Single Phase ◽  
Xrd Analysis ◽  
Preparation Process ◽  
Test Results ◽  
X Ray Diffraction ◽  
Crystal Water ◽  
X Ray ◽  
Co Precipitation ◽  
Scanning Electron

Nano-sized precursor FePO4·xH2O particles were obtained by oxidation co-precipitation using FeSO4⋅7H2O, H2O2 and ammonia. The powder was characterized by differential thermal analysis (DTA) and thermogravimetry (TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The TG-DTA results determined the content of crystal water of FePO4·xH2O, i.e. x = 1.5. The SEM observation suggested that FePO4·xH2O particles were spherical in shape and its grain size was about 150 nanometers. The dispersion of the synthesized powder was improved through the addition of surfactant. The XRD analysis indicated that the synthesized FePO4·xH2O was amorphous. After being calcined at 720 °C for 10 hrs, the synthesized FePO4·xH2O at pH of ~3.5 was crystallized and FePO4 in a single phase was obtained. According to the test results, the optimized preparation process parameters were determined.

Spark Plasma Sintering of Hybrid Nanocomposites of Hydroxyapatite Reinforced with CNTs and SS316L for Biomedical Applications

2020 ◽  
Vol 16 (4) ◽  
pp. 578-583
Author(s):  
Muhammad Asif Hussain ◽  
Adnan Maqbool ◽  
Abbas Saeed Hakeem ◽  
Fazal Ahmad Khalid ◽  
Muhammad Asif Rafiq ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Hybrid Nanocomposites ◽  
Homogeneous Distribution ◽  
Sintering Behavior ◽  
Stainless Steel 316L ◽  
Plasma Sintering ◽  
Spark Plasma

Background: The development of new bioimplants with enhanced mechanical and biomedical properties have great impetus for researchers in the field of biomaterials. Metallic materials such as stainless steel 316L (SS316L), applied for bioimplants are compatible to the human osteoblast cells and bear good toughness. However, they suffer by corrosion and their elastic moduli are very high than the application where they need to be used. On the other hand, ceramics such as hydroxyapatite (HAP), is biocompatible as well as bioactive material and helps in bone grafting during the course of bone recovery, it has the inherent brittle nature and low fracture toughness. Therefore, to overcome these issues, a hybrid combination of HAP, SS316L and carbon nanotubes (CNTs) has been synthesized and characterized in the present investigation. Methods: CNTs were acid treated to functionalize their surface and cleaned prior their addition to the composites. The mixing of nano-hydroxyapatite (HAPn), SS316L and CNTs was carried out by nitrogen gas purging followed by the ball milling to insure the homogeneous mixing of the powders. In three compositions, monolithic HAPn, nanocomposites of CNTs reinforced HAPn, and hybrid nanocomposites of CNTs and SS316L reinforced HAPn has been fabricated by spark plasma sintering (SPS) technique. Results: SEM analysis of SPS samples showed enhanced sintering of HAP-CNT nanocomposites, which also showed significant sintering behavior when combined with SS316L. Good densification was achieved in the nanocomposites. No phase change was observed for HAP at relatively higher sintering temperatures (1100°C) of SPS and tricalcium phosphate phase was not detected by XRD analysis. This represents the characteristic advantage with enhanced sintering behavior by SPS technique. Fracture toughness was found to increase with the addition of CNTs and SS316L in HAPn, while hardness initially enhanced with the addition of nonreinforcement (CNTs) in HAPn and then decrease for HAPn-CNT-SS316L hybrid nanocomposites due to presence of SS316L. Conclusion: A homogeneous distribution of CNTs and SPS technique resulted in the improved mechanical properties for HAPn-CNT-SS316L hybrid nanocomposites than other composites and suggested their application as bioimplant materials.

scholarly journals Preparation and characterization of corn starch/PVA/glycerol composite films incorporated with ε-polylysine as a novel antimicrobial packaging material

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Gao Yurong ◽  
Li Dapeng
Keyword(s):  
Water Solubility ◽  
Corn Starch ◽  
Composite Films ◽  
Antimicrobial Properties ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Packaging Material ◽  
Hydroxyl Group ◽  
Electron Microscopic ◽  
Antimicrobial Packaging

AbstractCorn starch/polyvinyl alcohol (PVA)/glycerol composite films incorporated with ε-polylysine were prepared, and their properties were investigated. The Fourier-transform infrared (FTIR) spectroscopy indicated that the interactions happened between the amino group of ε-polylysine and hydroxyl group starch/PVA composite films. X-ray diffraction (XRD) analysis showed that the addition of ε-polylysine decreased the intensity of all crystal peaks. Thermogravimetric (TGA) analysis suggested that ε-polylysine improved the thermal stability of composite films. Scanning electron microscopic (SEM) analysis showed that the upper surface of composite films incorporated with ε-polylysine presented more compact and flat surface. The antimicrobial activity of the composite film progressively increased with the increasing of ε-polylysine concentration (P < 0.05). The tensile strength, elongation at break and water absorption significantly increased, whereas water solubility decreased with the increasing of ε-polylysine concentration (P < 0.05). Therefore, the corn starch/PVA/glycerol composite films incorporated with ε-polylysine had good mechanical, physical and antimicrobial properties and could have potential application as a novel antimicrobial packaging material.

scholarly journals A Comparative Evaluation of Nanohydroxyapatite-Enriched Hydrogen Peroxide Home Bleaching System on Color, Hardness and Microstructure of Dental Enamel

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3072
Author(s):  
Riccardo Monterubbianesi ◽  
Vincenzo Tosco ◽  
Tiziano Bellezze ◽  
Giampaolo Giuliani ◽  
Mutlu Özcan ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Particle Diameter ◽  
Dental Enamel ◽  
Sem Analysis ◽  
Control Group ◽  
Average Particle ◽  
Color Analysis ◽  
Enamel Microstructure ◽  
Prismatic Structure ◽  
20 Nm

This study aimed to evaluate two hydrogen peroxide (HP)-based at-home bleaching systems in order to analyze whether nano-hydroxyapatite (nHA) addition may represent a reliable and safe solution for tooth whitening without altering dental microstructure and hardness. Human third molars (N = 15) were treated with two bleaching agents, one containing 6%HP (6HP) and the other 6% HP nHA-enriched (6HP-nHA) with average particle diameter ranging from 5–20 nm. Their effects on enamel were assessed using a spectrophotometer, Vickers microhardness (VMH) test and Scanning Electron Microscopy (SEM), comparing the treated groups with the non-treated control group (CTR). Color analysis revealed improvement in whiteness in both groups compared to CTR. VMH test results showed no differences among the groups. SEM analysis highlighted no evident changes in the enamel microstructure of tested groups compared to CTR. At high magnification, in 6HP group, a slight increase in irregularities of enamel surface morphology was observed, while 6HP-nHA group displayed removal of the aprismatic layer but preservation of the intact prismatic structure. These results suggest that the 6HP-nHA agent may be recommended to provide reliable whitening treatment, without damaging the enamel micromorphology and hardness.

scholarly journals Development of Nervilia fordii Extract-Loaded Electrospun PVA/PVP Nanocomposite for Antioxidant Packaging

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1728
Author(s):  
Peng Wen ◽  
Teng-Gen Hu ◽  
Yan Wen ◽  
Ke-Er Li ◽  
Wei-Peng Qiu ◽  
...  
Keyword(s):  
Food Packaging ◽  
Thermo Gravimetric Analysis ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Poly Vinyl Alcohol ◽  
Total Phenolic ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Phenolic And Flavonoid ◽  
Thermal Stability Of

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC50) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil’s oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.

scholarly journals Synthesis of Polymer-Based Magnetic Nanocomposite for Multi-Pollutants Removal from Water

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1742
Author(s):  
Fatimah Mohammed Alzahrani ◽  
Norah Salem Alsaiari ◽  
Khadijah Mohammedsaleh Katubi ◽  
Abdelfattah Amari ◽  
Faouzi Ben Rebah ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Magnetic Composite ◽  
Sample Treatment ◽  
Water Type ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Vibration Sample Magnetometer ◽  
Pollutants Removal ◽  
Co Precipitation ◽  
Red Dye

A magnetic polymer-based nanocomposite was fabricated by the modification of an Fe3O4/SiO2 magnetic composite with polypyrrole (PPy) via co-precipitation polymerization to form PPy/Fe3O4/SiO2 for the removal of Congo red dye (CR) and hexavalent chromium Cr(VI) ions from water. The nanocomposite was characterized using various techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), vibration sample magnetometer, and thermogravimetric analysis (TGA). The results confirm the successful fabrication of the nanocomposite in the size of nanometers. The effect of different conditions such as the contact time, adsorbent dosage, solution pH, and initial concentration on the adsorption process was investigated. The adsorption isotherm suggested monolayer adsorption of both contaminants over the PPy/Fe3O4/SiO2 nanocomposite following a Langmuir isotherm, with maximum adsorption of 361 and 298 mg.g−1 for CR dye and Cr(VI), respectively. Furthermore, the effect of water type on the adsorption process was examined, indicating the applicability of the PPy/Fe3O4/SiO2 nanocomposite for real sample treatment. Interestingly, the reusability of the nanocomposite for the removal of the studied contaminants was investigated with good results even after six successive cycles. All results make this nanocomposite a promising material for water treatment.

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