scholarly journals A study of preparing silver iodide nanocolloid by electrical spark discharge method and its properties

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kuo-Hsiung Tseng ◽  
Chu-Ti Yeh ◽  
Meng-Yun Chung ◽  
Yur-Shan Lin ◽  
Ning Qui
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Diffraction Analysis ◽  
Silver Iodide ◽  
Lattice Spacing ◽  
Spark Discharge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Discharge Method ◽  
Electrical Spark Discharge Method

AbstractThis study employed an electric discharge machine (EDM) and the Electrical Spark Discharge Method (ESDM) to prepare silver iodide nanocolloid (AgINC). Povidone–iodine (PVP-I) was dissolved in deionized water to create a dielectric fluid. Silver material was melted using the high temperature generated by an electric arc, and the peeled-off material was reacted with PVP-I to form AgI nanoparticles (AgINPs). Six discharge pulse wave parameter combinations (Ton–Toff) were employed, and the resultant particle size and suspension of the prepared samples were examined. The results revealed that AgINPs were successfully created using the ESDM. When Ton–Toff was set at 90–90 μs, the zeta potential of the AgINC was − 50.3 mV, indicating excellent suspension stability. The AgINC particle size was 16 nm, verifying that the parameters yielded AgINPs with the smallest particle size distribution and highest zeta potential. Ultraviolet–visible spectrum analyser was performed to analyse the samples, and the spectra indicated that the characteristic wavelength was 420 nm regardless of the Ton–Toff values. X-ray diffraction analysis determined that the AgINPs exhibited two crystal structures, namely β-AgI and Ag. Transmission electron microscopy was performed and revealed that the particles were irregularly shaped and that some of the larger particles had aggregated. The crystal structure was determined to be a mixture of Ag and β-AgI, with a lattice spacing of 0.235 nm and 0.229 nm, respectively. The lattice spacing of the Ag was 0.235 nm. X-ray diffraction analysis indicated that the prepared AgINC were composed of only Ag and I; no additional chemical elements were detected.

scholarly journals Parameters and properties for the preparation of Cu nanocolloids containing polyvinyl alcohol using the electrical spark discharge method

2021 ◽  
Vol 11 ◽  
pp. 184798042110351
Author(s):  
Kuo-Hsiung Tseng ◽  
Han-Chiao Ke ◽  
Hsueh-Chien Ku
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Zeta Potential ◽  
Polyvinyl Alcohol ◽  
Suspension Stability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Discharge Method ◽  
Electrical Spark Discharge Method

Through the use of an electric discharge machine, this study performed the electrical spark discharge method in deionised water under normal temperature and pressure for Cu nanocolloid (CuNC) preparation. The CuNCs had a zeta potential of 12.3 mV, indicating poor suspension stability. The suspension stability was effectively increased (zeta potential 32.5 mV) through the addition of polyvinyl alcohol (PVA) to form PVA-containing CuNCs PVA/CuNCs. Next, the following pulse-width modulation (Ton:Toff) parameters were tested to determine the optimal setting for PVA/CuNC preparation: 10:10, 30:30, 50:50, 70:70 and 90:90 µs. The optimal preparation parameter was then determined according to the absorbance, zeta potential and size distribution results. Finally, the surface properties and crystal structure of the PVA/CuNCs were characterised through transmission electron microscopy (TEM) and X-ray diffraction (XRD). When the Ton:Toff was set to 30:30 µs, preparation efficiency was optimal, as was suspension stability, as indicated by the absorbance value (0.534), zeta potential (32.5 mV) and size distribution (85.47 nm). Transmission electron microscopy revealed that Cu nanoparticles that were more dispersed in the PVA/CuNCs had a diameter smaller than 10 nm and a crystal line width of 0.2028 nm. X-ray diffraction showed that the PVA/CuNCs contained intact Cu crystal structures.

scholarly journals Deriving Optimized PID Parameters of Nano-Ag Colloid Prepared by Electrical Spark Discharge Method

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1091
Author(s):  
Kuo-Hsiung Tseng ◽  
Yur-Shan Lin ◽  
Yun-Chung Lin ◽  
Der-Chi Tien ◽  
Leszek Stobinski
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Electrical Discharge ◽  
Short Circuit ◽  
Spark Discharge ◽  
Chemical Pollution ◽  
Ag Colloid ◽  
Short Circuits ◽  
Discharge Method ◽  
Electrical Spark Discharge Method

Using the electrical spark discharge method, this study prepared a nano-Ag colloid using self-developed, microelectrical discharge machining equipment. Requiring no additional surfactant, the approach in question can be used at the ambient temperature and pressure. Moreover, this novel physical method of preparation produced no chemical pollution. This study conducted an in-depth investigation to establish the following electrical discharge conditions: gap electrical discharge, short circuits, and open circuits. Short circuits affect system lifespan and cause electrode consumption, resulting in large, non-nanoscale particles. Accordingly, in this study, research for and design of a new logic judgment circuit set was used to determine the short-circuit rate. The Ziegler–Nichols proportional–integral–derivative (PID) method was then adopted to find optimal PID values for reducing the ratio between short-circuit and discharge rates of the system. The particle size, zeta potential, and ultraviolet spectrum of the nano-Ag colloid prepared using the aforementioned method were also analyzed with nanoanalysis equipment. Lastly, the characteristics of nanosized particles were analyzed with a transmission electron microscope. This study found that the lowest ratio between short-circuit rates was obtained (1.77%) when PID parameters were such that Kp was 0.96, Ki was 5.760576, and Kd was 0.039996. For the nano-Ag colloid prepared using the aforementioned PID parameters, the particle size was 3.409 nm, zeta potential was approximately −46.8 mV, absorbance was approximately 0.26, and surface plasmon resonance was 390 nm. Therefore, this study demonstrated that reducing the short-circuit rate can substantially enhance the effectiveness of the preparation and produce an optimal nano-Ag colloid.

Role of Synthesis Parameters on Structural and Electrical Properties of M-Type Hexa-Ferrites

2012 ◽  
Vol 510-511 ◽  
pp. 201-205
Author(s):  
G. Asghar ◽  
S. Nasir ◽  
M.S. Awan ◽  
G.H. Tariq ◽  
M. Akram ◽  
...  
Keyword(s):  
Particle Size ◽  
Diffraction Analysis ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Narrow Particle Size Distribution ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Volume Rate ◽  
Synthesis Parameters

Phase purity, particle size and its distribution contributes a lot to the physical properties of M-type hexa-ferrites. These parameters are strongly influenced by the variation in synthesis parameters. In the present work, effect of synthesis parameters such as molar ratio (Fe/Sr) and volume rate of addition of precipitating agent on M-type hexa-ferrite (SrFe12O19) prepared by co-precipitation method have been investigated systematically. The molar ratio (Fe/Sr) in SrFe12O19was varied as 12, 11, 10, 09, and 08. X-ray diffraction analysis revealed that molar ratio does not affect the phase purity. X-ray diffraction analysis of the samples prepared with different volume rate of addition of precipitating agent indicated that phase purity and micro-structural properties of SrFe12O19are greatly influenced by the above synthesis parameter. High volume rate of addition of precipitating agent resulted in high phase purity, smaller particle size, and narrow particle size distribution.

Textured Ti3SiC2 by EPD in a Strong Magnetic Field

2012 ◽  
Vol 507 ◽  
pp. 15-19 ◽  
Author(s):  
Mrinalini Mishra ◽  
Yoshio Sakka ◽  
Chun Feng Hu ◽  
Tohru Suzuki ◽  
Tetsuo Uchikoshi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Zeta Potential ◽  
Diffraction Analysis ◽  
Strong Magnetic Field ◽  
Side Surface ◽  
Cationic Polyelectrolyte ◽  
Max Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Suspension Parameters

We present a method for fabrication of textured MAX phase ceramics, particularly, Ti3SiC2; by EPD in a strong magnetic field (12T). Ti3SiC2 was dispersed in cationic polyelectrolyte-Polyethylenimine (PEI). Addition of 0.3-1dwb PEI resulted in high zeta potential values and suspension was found to be stable and of good fluidity. The optimized suspension parameters for EPD were determined as 10vol% Ti3SiC2 and 1dwb PEI in 50 % ethanolic water at pH ~ 7. X-ray diffraction analysis of the textured samples revealed that the preferred orientation of Ti3SiC2 grains parallel to the magnetic eld direction was along the a,b-axis. The Lotgering orientation factors on the textured top surface and textured side surface were determined as f (hk0) = 0.35 and f (00l) = 0.75, respectively.

NANOSIZE POWDERS OF SILVER-DOPED SODIUM COBALT OXIDE SYNTHESIZED BY POLYMERIZED COMPLEX METHOD

2005 ◽  
Vol 04 (02) ◽  
pp. 237-244 ◽  
Author(s):  
TOSAWAT SEETAWAN ◽  
VITTAYA AMORNKITBAMRUNG ◽  
THANUSIT BURINPRAKHON ◽  
SANTI MAENSIRI
Keyword(s):  
Particle Size ◽  
Diffraction Analysis ◽  
Single Phase ◽  
Complex Method ◽  
X Ray Diffraction ◽  
Nanosized Powders ◽  
X Ray ◽  
Sodium Cobalt Oxide ◽  
Subsequent Calcination ◽  
Pc Method

Nanosized powders used for the preparation of bulk Na1.5Co2O4 and Ag -doped Na1.5Co2O4 nanosized crystalline grains were synthesized by the polymerized complex (PC) method. X-ray diffraction analysis revealed that the nondoped and Ag -doped PC products were composed of Co3O4 and Na2CO3 phases. After a subsequent calcination at 800°C, the nondoped PC product was converted to powder of single phase γ- NaxCo2O4 , whereas the Ag -doped PC products remained as mixed phases of Co3O4 and Na2CO3 and Ag2O with a small trace of γ- NaxCo2O4 . SEM and TEM investigations showed that all the calcined products were powders of about 200–500 nm particle size.

scholarly journals Molybdenum(VI) oxide: New methods of synthesis and properties

2020 ◽  
Vol 15 (2) ◽  
pp. 67-76
Author(s):  
E. E. Nikishina ◽  
E. N. Lebedeva ◽  
D. V. Drobot
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Physicochemical Properties ◽  
Diffraction Analysis ◽  
Molybdenum Trioxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Methods ◽  
Oxide Phases ◽  
Molybdenum Pentachloride

Objectives. The present study aims to develop new methods for the synthesis of molybdenum(VI) oxide, which is a precursor for the synthesis of functional materials, as well as to investigate the physicochemical properties of the resulting oxide phases. Methods. The synthesized phases and the products of their thermolysis were studied by differential thermal analysis, IR spectroscopy, X-ray diffraction analysis, and granulometry. Results. Three methods for the synthesis of molybdenum(VI) oxide were developed, and the physicochemical properties of the oxide phases obtained were studied. The first method consisted in the reaction of molybdenum pentachloride with a 6.0–9.5 mol/L ammonia solution, the second one was the reaction of niobium pentachloride with a sulfuric acid solution, and the third method involved the reaction of ammonium molybdate with nitric acid, affording brown molybdenum(V) MoO(OH)3 hydroxide, a bright blue precipitate of molybdenum blue MoO2.75, and white hydrated oxide MoO3·H2O, respectively. Conclusions. A series of thermal and X-ray diffraction analysis demonstrated that in all cases the samples were amorphous phases. Heat treatment at 580 °C of the synthesized phases led to the formation of a rhombic modification of molybdenum trioxide. The lattice parameters and X-ray density were calculated for all thermolysis products. The effect of heat treatment on the particle size of the synthesized samples and their thermolysis products was studied. Particle size analysis demonstrated that particles of different diameters were formed depending on the synthetic method. The smallest particle size (0.3–0.6 µm) was found in molybdenum trioxide, a product of the thermolysis of the sample obtained by the reaction of molybdenum pentachloride with a concentrated ammonium solution. 

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