scholarly journals Studies on Black Iron Oxide Pigment. Part-II: Effect of Preparation Parameter on Particle Size and Microstructure of Ferrosoferric Oxide

1970 ◽  
Vol 44 (1) ◽  
pp. 31-40 ◽  
Author(s):  
AJM Tahuran Neger ◽  
Aftabuddin Ahmed ◽  
Sufia Parvin ◽  
AM Shafiqul Alam

This paper deals with the effect of preparation parameter on particle size and microstructure of the prepared ferrosoferric oxide. 10 prepared samples (from 23 samples) and one standard sample (Bayferrox 318 standard 88) collected from BAYER, Germany was selected for this study. X-ray diffraction, petrographic microscopy, scanning electron microscope and particle size analyzer were used to characterize the phase present, particle size and shape of the particle. It is observed from X-ray diffraction that all these samples mainly contain Fe3O4 phase. The shape of the particle is found to be round and agglomerated. The average particle diameter of highest portion of pigment in the peak region is ranged from 12.25μ to 17.32μ, which is very similar to the standard sample (17.32μ). Sample number 9, which was prepared with ferrous sulphate, hydrochloric acid, sodium nitrate and ammonium hydroxide at a molar ratio 1:1.74:0.16:4.07 and standard sample contain narrow high peak in their particle size distribution curve. Another observation is that, experimental parameter, though have some effect on particle size but have no effect on microstructure. Key words: Black iron oxide, Pigment, Particle size, Microstructure, Ferrosoferric oxide.     doi: 10.3329/bjsir.v44i1.2711 Bangladesh J. Sci. Ind. Res. 44(1), 31-40, 2009

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.


Author(s):  
Rajni Bhardwaj ◽  
Smita Johar ◽  
Amit Kapila ◽  
Amandeep Sharma

Swarnamakshika is grouped under Updhatu of Swarna and is composed of Copper, Iron and Sulphur. In this study Swarnamakshika was subjected to Shodhana by Bharjana with Nimbuka swarasa and Shudha Swarnamakshika was given Bhavana with Nimbuka swarasa and subjected to Varahaputa. With ten Varahaputa Bhasma Siddhi Lakshanas were attained swarnamakshika Marana was done by using Nimbuka swarasa until bhasma siddi lakshanas found and it took 10 puta till it attained reddish brown color. The X-ray diffraction analysis showed that d-identified peaks after 10th puta Swarnamakshika bhasma composition is of Iron oxide with rhombohedral crystal system as main component. EDX analysis of Swarna makshika bhasma shows that it contains Iron and Oxygen, as major element and Copper, Sulphur, Carbon, Aluminium, Calcium etc. as minor elements. FESEM study revealed that the particle size of Ashudha and Shudha Swarnamakshika was in the range of 500 nm-3nm. Keywords: Swarnamakshika Bhasma, Nimbuka swarasa, puta


2012 ◽  
Vol 554-556 ◽  
pp. 18-22
Author(s):  
Supakorn Silakate ◽  
Anucha Wannagon ◽  
Apinon Nuntiya

The objectives of this study were to prepare leadless crystalline glazes from iron oxide by using low temperature firing (1,100°C) and to study the effect of concentration of iron oxide on the phase composition of the glaze raw materials on phase transformation in leadless iron oxide crystalline glaze. The crystalline phases were investigated by using the DTA, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The composition of the glaze raw materials compose of nepheline syenite, colemanite, pottery stone, bentonite, ZnO, Li2CO3, SiOSubscript text2 and 10, 15 and 20%(w/w) iron oxide (Fe2O3). The glaze raw materials were ground for homogeneous mixtures by ball milling for 24h. The average particle size of the mixture was 3.86 µm. The glaze bodies were carried to firing at 1,100°C at the heating rate of 2°C/min and soaking for 0.5h. Then, the glaze bodies were cooled at the cooling rate of 1°C/min and maintained at 1,080°C for 3h and then maintained at 980°C for 1h, respectively. From the experiment results, it was found that the crystallization temperatures (Tc) of franklinite (ZnFe2O4) and anorthite (CaAl2Si2O8) depend on the concentration of iron oxide content.


1970 ◽  
Vol 43 (2) ◽  
pp. 183-196
Author(s):  
AJM Tahuran Neger ◽  
Sufia Parvin ◽  
Aftabuddin Ahmed ◽  
AM Shafiqul Alam

Black iron oxide pigment has been successfully prepared by traditional method. Ferrous sulphate was used as the starting iron source. The effect of amount of acid, type and amount of alkali and oxidizing agent on colour and yield were also studied. It was found that, the conversion of insitu produced ferrous chloride to ferrosoferric oxide yielded brilliant colour hue than that produced directly from ferrous sulphate. The produced ferrosoferric oxide were analyzed for purity and characterized for physical properties to be used as a pigment. The prepared samples were found to be comparable with BAYER bayferrox 318. Statistical evaluation also confirmed the experimental result. Key words : Black oxide pigment, Optical properties, Ferrous sulphate, Oxidizing agent  DOI: 10.3329/bjsir.v43i2.962 Bangladesh J. Sci. Ind. Res. 43(2), 183-196, 2008 


2015 ◽  
Vol 1098 ◽  
pp. 104-109 ◽  
Author(s):  
Abul Kalam Azad ◽  
D.D.Y. Setsoafia ◽  
L.C. Ming ◽  
Iskandar Petra

Rare-earth-doped BaCeO3and BaZrO3electrolytes with perovskite structure have been studied extensively in developing proton conducting intermediate temperature SOFC. Acceptor doped alkaline earth cerates and zirconates have been thoroughly studied because of the great interest in their possible applications as solid proton conductors. The perovskite type proton conductor BaCe0.5Zr0.35In0.1Zn0.05O3-δwas prepared in the traditional solid state reaction method. The density of the sample obtained about 96% of the theoretical density after sintering at 1350 °C and X-ray diffraction study confirms the pure phase. Rietveld refinement of the neutron and X-ray powder diffraction data shows that this material crystallizes in the orthorhombic symmetry in the space group Pm3m. Particle size measurement shows that the average particle size is about 2.4 μm. The average thermal expansion at 894 °C was 9.49 x 10-6/°C. Thermogravimetric analysis (TGA) traces obtained for the sample on heating in wet air shows that the maximum proton uptake occurs from 595 °C.


2021 ◽  
Vol 11 (10) ◽  
pp. 4638
Author(s):  
Jose Luis López-Miranda ◽  
Rodrigo Esparza ◽  
Marlen Alexis González-Reyna ◽  
Beatriz Liliana España-Sánchez ◽  
Angel Ramon Hernandez-Martinez ◽  
...  

This work reports, for the first time, the synthesis of silver nanoparticles using extracts of the species of Sargassum natans and Sargassum fluitans (AgNPs-S). Their antibacterial and catalytic properties are compared with silver nanoparticles obtained by chemical synthesis (AgNPs-C). The characterization of AgNPs-S and AgNPs-C was carried out using ultraviolet–visible spectroscopy (UV–Vis), dynamic light scattering (DLS), zeta potential, a scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis. The synthesis of silver nanoparticles using Sargassum extract was optimized through varying experimental parameters, such as the type of solvent used to prepare the extract, the volume of the extract, and the pH of the system. The most efficient sample (AgNPs-S) was prepared with a water–ethanol-based extract, using a 3:1 volumetric ratio of extract: a precursor salt with the addition of 1 mL of NaOH pH = 14. The AgNPs-C were spherical in shape, with an average particle size of 11.55 nm, while the AgNPs-S were polyhedral shaped, with an average particle size of 26.39 nm. The synthesized AgNPs-S were found to have significantly higher catalytic activity for the degradation of methylene blue and more effective antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa than AgNPs-C.


1991 ◽  
Vol 6 (4) ◽  
pp. 712-718 ◽  
Author(s):  
A.G. Fox ◽  
S.C. Fuller ◽  
C.E. Whitman ◽  
V. Radmilovic

An x-ray diffractogram was generated from a powder sample of solution treated and ice brine quenched Al–14.25 at.% Li alloy. The Bragg reflections obtained were characteristic of a very-nearly fully ordered Al-rich L12 phase based on δ'Al3Li together with two very weak reflections associated with δAlLi. All the lines were significantly broadened due to particle size effects. The average particle size associated with the 100 L12 superlattice line was found to be 4.2 (3) nm and with the fundamental lines, 26.8 nm. A simple structure factor calculation indicated the volume fraction of ordered phase to be around 0.77, assuming that the lack of maximum order was due to the presence of disordered fcc AlLi solid solution. These results suggest that the microstructure of this as-quenched alloy comprises ordered regions of about 4 nm in size in a sea of disordered matrix with a very small amount of δAlLi present. This conclusion is in excellent agreement with recent small angle x-ray and transmission electron microscope studies on similar alloys and suggests that AlLi alloys which are ostensibly disordered at high temperatures go through a disorder-order transformation and then decompose into regions of order and disorder which are associated with a composition spinodal.


2019 ◽  
Vol 13 (2) ◽  
pp. 210-217
Author(s):  
Milica Vucinic-Vasic ◽  
Bratislav Antic ◽  
Marko Boskovic ◽  
Aleksandar Antic ◽  
Jovan Blanusa

Nanocomposites (HAp/iron oxide), made of hydroxyapatite (HAp) and ferrimagnetic iron oxide, were synthesized by high-energy ball milling a mixture consisting of iron oxide nanoparticles and the starting materials used for the HAp synthesis: calcium hydrogen phosphate anhydrous (CaHPO4), and calcium hydroxide (Ca(OH)2). Two HAp/iron oxide samples with the magnetic phase content of 12 and 30 wt.% were prepared and their microstructure, morphology and magnetic properties were analysed by X-ray diffraction and transmission electron microscopy. Furthermore, the measurement of particle size distribution was performed by laser scattering, and temperature/field dependence on magnetization was determined. X-ray diffraction data confirmed the formation of two-phased samples (HAp and spinel iron oxide) without the presence of any other parasite phase. The shape of particles was nearly spherical in both samples, ranging from only a few to several tens of nanometres in diameter. These particles formed agglomerates with the most common value of the number-based particle size distribution of 380 and 310 nm for the sample with 12 and 30wt.% of iron oxide, respectively. Magnetization data showed that both HAp/iron oxide composites had superparamagnetic behaviour at room temperature.


2019 ◽  
Vol 13 (4) ◽  
pp. 368-375
Author(s):  
Xingrui Li ◽  
Bingbing Fan ◽  
Haowei Jia ◽  
Xuewen Shi ◽  
Yilin Zhang ◽  
...  

CaZrO3-modified (K0.48Na0.48Li0.04)(Nb0.95Sb0.05)O3 (CZ-KNLNS) lead-free piezoelectric powders were synthesized by microwave method followed by conventional solid state sintering. Different amounts of CaZrO3 were added (i.e. x = 0, 0.02, 0.03, 0.04, 0.06 mol) and their effects on the crystal structure, microstructure, as well as the electrical properties, were investigated. The results showed that CZ-KNLNS powders could be obtained by microwave heating at a relatively low temperature and short time of 650 ?C and 10min, respectively. The obtained CZ-KNLNS powders have cubic structure and good crystallinity with average particle size of 300-700 nm. The particle size gradually decreases with the increase of CaZrO3 amount, indicating that addition of CaZrO3 inhibits the growth of the particles. The powders were further sintered at 1120 ?C for 4 h and CZ-KNLNS ceramics with homogeneous and highly dense microstructure were obtained. X-ray diffraction showed that, with increasing CaZrO3 content, the phase structure gradually changed from orthorhombic to rhombohedral, which can be considered as the coexistence zone of orthorhombic-rhombohedral (O-R) phase in the range of 0.03 < x < 0.06. The optimized content of CaZrO3 is x = 0.04, at which the CZ-KNLNS piezoelectric ceramics show good properties and maximum d33 = 201.2 pC/N and Kp = 36.8%.


Author(s):  
Carolina Gonzalez Morales ◽  
Miller Alonso Camargo-Valero ◽  
Francisco José Molina Pérez ◽  
Belén Fernández

The formation of struvite (MgNH4PO4·6H2O) for nutrient recovery in wastewater treatment plants has been widely investigated; however, little attention has been paid to the effect of stirring speeds on the resulting particle size, which could affect its agronomic value as a slow-release fertilizer. In this study, struvite formation from the centrate of sewage digestate was performed under six stirring speeds (0, 100, 200, 300, 400, 500 rpm). The resulting struvite crystals were characterised using X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy. The average particle size of struvite crystals increased from 55 µm at 0 rpm to 127 µm at 100 rpm and 128 μm at 200 rpm.  Further increments in stirring speeds resulted in smaller crystal sizes. These results indicated that the largest particle size can be obtained at stirring speeds ranging from 100 to 200 rpm, equivalent to a velocity gradient between 79 and 188 s-1, as there was no statistically significant difference between mean values (t-test, p<0.05). The optimum stirring speed range reported herein can be used to set operational conditions for struvite crystallisation with the benefit of producing large crystals and reducing energy consumption in stirring tanks.


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