Effect of Powder Properties of Dielectric Filler on the Dielectric Properties of a Ceramics-Polymer Composite

2006 ◽  
Vol 320 ◽  
pp. 205-208
Author(s):  
Isao Kanada ◽  
Norimasa Sakamoto

Effects of powder properties of the filler, including the particle size, the specific surface area and the lattice strain on the dielectric permittivity and Q of the ceramics-polymer composites were investigated in order to achieve composites with high dielectric permittivity and Q. The dielectric properties of the composites were strongly influenced by the powder properties of the filler, despite that the fillers have the same composition. Generally, lower specific surface area and lower lattice strain of the filler lead to higher Q of the composites.

2012 ◽  
Vol 512-515 ◽  
pp. 2434-2438
Author(s):  
Quan Xiao Liu ◽  
Wen Cai Xu

In this paper the comparison among some papermaking powder properties are studied. It shows that the properties of different powders are different because of different chemical composition and different preparation method and their particle size is different for different purpose such as filler and pigment. The particle size of powder for pigment powder is smaller than that for filler. The specific surface area of papermaking filler is lower than 20m2/g, the absorption value of DBP is about 45cm3/100g, the whiteness is up to 90%, and the particle size is about 3µm. The specific surface area of papermaking pigment is lower than 25m2/g, the absorption value of DBP is from 40 cm3/100g to100cm3/100g, the whiteness of clay is up to 50%, the whiteness of GCC and PCC is up to 90%, and the particle size is lower than 2µm. The specific surface area of silica is up to 100m2/g, the absorption value of DBP is up to 100cm3/100g, the whiteness is up to 97%, and the particle size is around 5µm.


2021 ◽  
Vol 316 ◽  
pp. 689-693
Author(s):  
K.D. Naumov ◽  
V.G. Lobanov

The aim of this paper is to establish a regulatory change of zinc powders key physicochemical properties with varying electroextraction conditions. It was studied influence zinc concentration, alkali concentration and current density. Quantitative dependencies of zinc powders particle size and specific surface area from mentioned electroextraction parameters are shown. At increasing of zinc concentration, decreasing of NaOH concentration and decreasing of current density of powders particle size growth, correspondingly specific surface area is declined. It is indicated, that electrolytic zinc powders bulk density varies from 0.61 g/cm3 to 0.75 g/cm3 with a decrease of average particle size from 121 μm to 68 μm. In comparison, spherical powders bulk density used in various industries is currently 2.45-2.6 g/cm3. In all experiments, metal zinc content varied in the range of 91.1-92.5%, the rest - ZnO. To a greater extent, this indicator depends on powder washing quality from alkali and storage conditions.


2011 ◽  
Vol 10 (2) ◽  
pp. 25
Author(s):  
Anirut Leksomboon ◽  
Bunjerd Jongsomjit

In this present study, the spherical silica support was synthesized from tetraethyloxysilane (TEOS), water, sodium hydroxide, ethylene glycol and n-dodecyltrimethyl ammonium bromide (C12TMABr). The particle size was controlled by variation of the ethylene glycol co-solvent weight ratio of a sol-gel method preparation in the range of 0.10 to 0.50. In addition, the particle size apparently increases with high weight ratio of co-solvent, but the particle size distribution was broader. The standard deviation of particle diameter is large when the co-solvent weight ratio is more than 0.35 and less than 0.15. However, the specific surface area was similar for all weight ratios ranging from 1000 to 1300 m2/g. The synthesized silica was spherical and has high specific surface area. The cobalt was impregnated onto the obtained silica to produce the cobalt catalyst used for CO2 hydrogenation.</


2005 ◽  
Vol 284-286 ◽  
pp. 365-368 ◽  
Author(s):  
Yin Zhang ◽  
Yoshiyuki Yokogawa ◽  
Tetsuya Kameyama

The effect of different particle sizes on the flexural strength and microstructure of three different types of hydroxyapatite (HAp) powders was studied. The powder characteristics of laboratory synthesized HAp powder (Lab1 and Lab2) were obtained through a wet milling method, and the median particle size and the specific surface area of powders are different with the dryness period. The median particle sizes of Lab1 and Lab2 are 0.34 µm and 0.74 µm, and the specific surface areas of Lab1 and Lab2 are 38.01 m2/g and 19.77 m2/g. The commercial HAp had median particle size of 1.13 µm and specific surface area of 11.62m2/g. The different powder characteristics affected the slip characteristics, and the flexural strength and microstructure of the sintered porous HAp bodies are also different. The optimum value for the minimum viscosity in these present HAp slip with respect to its solid loading and the optimum amount of the deflocculant were investigated. The flexural strengths of the porous HAp ceramics prepared by heating at 1200°C for 3 hrs in air were 17.59 MPa for Lab1 with a porosity of 60.48%, 10.51 MPa for Lab2 with a porosity of 57.75%, and 3.92 MPa for commercial HAp with a porosity of 79.37%.


2019 ◽  
Vol 7 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Biao Zhao ◽  
Mahdi Hamidinejad ◽  
Chongxiang Zhao ◽  
Ruosong Li ◽  
Sai Wang ◽  
...  

A microcellular structure can effectively tune the dielectric properties of PVDF/carbon composite foams.


2008 ◽  
Vol 587-588 ◽  
pp. 468-472
Author(s):  
J.M. González ◽  
José A. Rodríguez ◽  
Enrique J. Herrera

Nickel powder was dry-milled using a high-energy disc-oscillating mill. The average particle size increases and the specific surface area diminishes with milling time. Crystallite size decreases and microstrains increase, under the same conditions, as shown by X-ray analysis. At 120 min milling time, the crystallite size has a value of 17 nm, i.e., a nanostructured powder, with a perturbed lattice, is obtained. The above results have been compared with published data about the effects of milling on a ceramic powder. There is, in both cases, a general agreement concerning the changes produced in crystallite size. Nevertheless, opposite results are reached regarding particle size and specific surface area.


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