Synthesis of Titania Nanoparticles via Spark Discharge Method Using Air as a Carrier

2007 ◽  
Vol 544-545 ◽  
pp. 143-146 ◽  
Author(s):  
Hyun Cheol Oh ◽  
Jun Ho Ji ◽  
Jae Hee Jung ◽  
Sang Soo Kim
Keyword(s):  
Primary Particle ◽  
Spark Discharge ◽  
Titania Nanoparticles ◽  
Particle Sizes ◽  
Discharge System ◽  
Carrier Gas ◽  
Air Atmosphere ◽  
Aerosol Generator ◽  
Discharge Method ◽  
Pulsed Spark Discharge

A pulsed spark-discharge aerosol generator using air as a carrier gas was successfully applied to the titania nanoparticle production. The titanium vapor evaporated by spark discharge was subsequently supersaturated and condensed to titania nanoparticles by nucleation and condensation. The size and concentration of the particles can be controlled easily using air as a carrier gas by altering the repetition frequency, capacitance, gap distance, and flow rate of the spark-discharge system. TEM observation shows that the generated particles were aggregates, which primary particle sizes are a few nanometers. The element composition of the nanoparticles was titanium and the crystal phase was amorphous. XPS analysis shows that oxidation state of generated particles corresponded to TiO2. These XPS data indicates that some fraction of the evaporated titanium vapor could be oxidized in an air atmosphere by the oxidation with oxygen. However, enough time for crystallization was lacked because of raid cooling.

Generation of Silver Nanoparticles by Spark Discharge Aerosol Generator Using Air as a Carrier Gas

2006 ◽  
Vol 30 (2) ◽  
pp. 170-176
Author(s):  
Hyun-Cheol Oh ◽  
Jae-Hee Jung ◽  
Hyung-Ho Park ◽  
Jun-Ho Ji ◽  
Sang-Soo Kim
Keyword(s):  
Silver Nanoparticles ◽  
Spark Discharge ◽  
Carrier Gas ◽  
Aerosol Generator

Effects of Particles Size of Nanosilica on Properties of Polybenzoxazine Nanocomposites

2015 ◽  
Vol 659 ◽  
pp. 394-398 ◽  
Author(s):  
Nutthaphon Liawthanyarat ◽  
Sarawut Rimdusit
Keyword(s):  
Particle Size ◽  
Silica Nanoparticles ◽  
Primary Particle ◽  
Mechanical And Thermal Properties ◽  
Particle Sizes ◽  
Barrier Effect ◽  
Degradation Temperature ◽  
Maximum Value ◽  
Wetting Behaviors ◽  
Composite Samples

Polybenzoxazine nanocomposites filled with three different sizes of silica nanoparticles are investigated for their mechanical and thermal properties. In this research, silica nanoparticles with primary particle sizes of 7, 14 and 40 nm were incorporated in polybenzoxazine matrix at a fixed content of 3% by weight. From the experimental results, the storage modulus of the polybenzoxazine nanocomposite was found to systematically increase with decreasing the particle sizes of nanosilica suggesting better reinforcement of the smaller particles. Glass transition temperature was found to slightly increase with the addition of the silica nanoparticles. The uniformity of the composite samples were also evaluated by thermogravimetric analysis to show good dispersion of the silica nanoparticles in the composite samples as a result of high processability of the benzoxazine resin used i.e. low A-stage viscosity with good wetting behaviors. Degradation temperature at 5% weight loss (Td,5) of polybenzoxazine nanocomposites filled with different particle sizes of silica nanoparticles was found to increase from the value of 325 °C of the neat polybenzoxazine to the maximum value of about 340 °C with an addition of the nanosilica of the smallest particle size used. Finally, the smaller nanosilica particle size was also found to show more pronounced effect on Td,5enhancement of the composite samples as a result of greater barrier effect from larger surface area of the smaller particles.

Effects of solution volume on hydrogen production by pulsed spark discharge in ethanol solution

2016 ◽  
Vol 23 (7) ◽  
pp. 073509 ◽  
Author(s):  
Y. B. Xin ◽  
B. Sun ◽  
X. M. Zhu ◽  
Z. Y. Yan ◽  
H. Liu ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Ethanol Solution ◽  
Spark Discharge ◽  
Pulsed Spark Discharge ◽  
Solution Volume

Characteristic Analysis and Electrical Conductivity of Graphene and Graphene-Nanosilver Prepared by Electrical Spark Discharge Method

2021 ◽  
Author(s):  
Kuo-Hsiung Tseng ◽  
Chu-Ti Yeh ◽  
Hsueh-Chien Ku ◽  
Der-Chi Tien ◽  
Leszek Stobinski
Keyword(s):  
Sheet Resistance ◽  
Spark Discharge ◽  
High Dispersion ◽  
Raman Signal ◽  
Characteristic Analysis ◽  
Graphene Layers ◽  
Ag Colloid ◽  
Xrd Patterns ◽  
Discharge Method ◽  
Electrical Spark Discharge Method

Abstract This study used an electric discharge machine (EDM) to perform the electrical spark discharge method (ESDM) to prepare a graphene colloid and a graphene-Ag colloid. The characteristic wavelengths of graphene, and graphene-Ag are both 262 nm. They had the properties of high dispersion and are unlikely to aggregate. The XRD patterns of graphene and graphene-Ag are typical carbon diffraction peak angles and crystal orientations. Graphene-Ag in DW can increase the Raman signal intensity of graphene. Regarding the graphene colloid and graphene-Ag colloid, their average sheet resistance values are 0.0329 MΩ/sq and 0.00136 MΩ/sq, respectively. Moreover, when AgNPs composited with graphene layers, the average sheet resistance is only 1/24 that of graphene layers, indicating that graphene-Ag has superior conductivity.

Sign in / Sign up

Export Citation Format

Share Document