scholarly journals Strength of hierarchically porous ceramics: Discrete simulations on X-ray nanotomography images

2016 ◽  
Vol 113 ◽  
pp. 250-253 ◽  
Author(s):  
Denis Roussel ◽  
Aaron Lichtner ◽  
David Jauffrès ◽  
Julie Villanova ◽  
Rajendra K. Bordia ◽  
...  
2008 ◽  
Vol 73 (7) ◽  
pp. 745-751 ◽  
Author(s):  
Adela Egelja ◽  
Jelena Gulicovski ◽  
Aleksandar Devecerski ◽  
Biljana Babic ◽  
Miroslav Miljkovic ◽  
...  

Coniferous wood (fir) was transformed by pyrolysis into carbon preforms, which were subsequently converted into biomorphic ceramics by the pressure infiltration technique with colloidal silica. An in situ reaction between the silica and the carbon template occurred in the cellular wall at a high sintering temperature. Depending on the employed atmosphere, non-oxide (SiC) or oxide (SiO2) ceramics were obtained. The morphology of the resulting porous ceramics and their phase composition were investigated by scanning electron microscopy (SEM/EDX) and X-ray diffraction (XRD). The experimental results showed that the biomorphic cellular morphology of the wood maintained in both the SiC and silica ceramics, which consisted of only the b-SiC phase and SiO2, respectively. .


2015 ◽  
Vol 51 (9) ◽  
pp. 951-957 ◽  
Author(s):  
K. M. Gerke ◽  
D. V. Korost ◽  
R. V. Vasilyev ◽  
M. V. Karsanina ◽  
V. P. Tarasovskii
Keyword(s):  

2016 ◽  
Vol 697 ◽  
pp. 399-403 ◽  
Author(s):  
Xian Gong Deng ◽  
Jun Kai Wang ◽  
Hai Jun Zhang ◽  
Jiang Hao Liu ◽  
Shao Wei Zhang

Magnesium aluminate spinel (MgAl2O4) porous ceramics were in-situ synthesized by heating the mixture of Al2O3 and MgCO3 with MgCl2 salt at 1400~1600 °C for 3 h, and then characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The morphology of as-prepared MgAl2O4 porous ceramics was dependent on the addition of MgCl2, and it indicated that the MgCl2 molten salt not only acted as a template for pore formation of the porous ceramics, but also provided a liquid environment for the synthesis of MgAl2O4.


2003 ◽  
Vol 788 ◽  
Author(s):  
Predrag Kisa ◽  
Patrick Fisher ◽  
Al Olszewski ◽  
Ian Nettleship ◽  
Nicholas G. Eror

ABSTRACTThis study investigated the microstructural characteristics of directionally solidified freeze-dried silica sols. Porous structures were formed by depositing silica sol on silicon (100) single crystals. The deposited sols were unidirectionaly solidified by placing the silicon substrate on a copper block immersed in liquid nitrogen and then subsequently freeze-dried. Freeze drying removal of ice crystals created three-dimensional pore channels ranging from 3 to10 micrometers in diameter aggregated in grain like colonies 50–100 micrometers in diameter. Pore size, spacing, colony size and microstructure were determined using optical microscopy (OM) and scanning electron microscopy (SEM) while the structure of the amorphous SiO2 was characterized by X-ray diffraction (XRD). The microstructure results are compared and contrasted with silica aerogel obtained through conventional processing using supercritical CO2.


2020 ◽  
Vol 22 (34) ◽  
pp. 18860-18867 ◽  
Author(s):  
Matthew E. Potter ◽  
Mark E. Light ◽  
Daniel J. M. Irving ◽  
Alice E. Oakley ◽  
Stephanie Chapman ◽  
...  

Novel in situ synchrotron total scattering measurements probe the assembly of primary building units into templated hierarchically porous aluminophosphate catalysts, providing unique insights to understanding crystallisation kinetics.


2008 ◽  
Vol 3 (4) ◽  
pp. 40-46
Author(s):  
Dmitriy Yu. Trufanov ◽  
Andrey V. Nomoev ◽  
Molon D. Buyatuev ◽  
Dashima Zh. Bazarova ◽  
Deleg Sangaa ◽  
...  

The present paper describes the possibility of strong porous ceramics preparation from hydroxyapatite nanopowders. The as-dried hydroxyapatite nanopowders were uniaxially compacted and sintered. The sintered ceramics and nanopowders were analyzed by methods of transition electron microscopy, scanning electron microscopy and X-ray phase diffraction. The ceramics gas-penetration and hardness were measured. The methods of pore control were tested. The ceramics samples with open equally dispersed pores were received; the pores and grain size is about micron and less. The results are useful for making medical implantate and membrane ceramics with controlled pores size.


2014 ◽  
Vol 979 ◽  
pp. 66-69
Author(s):  
P. Chankachang ◽  
S. Chantara ◽  
S. Punyanitya ◽  
C. Saelee

In this work, hydroxyapatite (HA) powder derived from pig bone was prepared by thermal processes. The effect of heat treatment temperatures on crystallinity and microstructure of the HA powder were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The powders are uniaxially compact and then sintering at 900°C-1050°C in air. The microstructural characterization of the porous was carried out by SEM. Filtration studies using the sintered porous HA ceramic were performed for sanitary wastewater. The analysis of raw water sample and filtered water were performed. The results showed that the water permeated through the porous HA ceramics could be cleaner water to meet of environmental standard.


2014 ◽  
Vol 1070-1072 ◽  
pp. 530-533
Author(s):  
Yu Rong Liu ◽  
Jia Liu

Hierarchically porous carbon (HPC)/MnO2 nanocomposites were fabricated for asymmetric supercapacitor applications. The microstructures of HPC/MnO2 nanocomposites were characterized by X-ray diffraction and scanning electron microscopy. The asymmetric supercapacitor consisting of a HPC/MnO2 cathode and a HPC anode shows an excellent performance with energy density and power density of 23.8 Wh kg-1 and 12.5 kW kg-1, respectively. In addition, the asymmetric supercapacitor exhibits an excellent cycle life with 91% retention of capacitance after 1000 cycles.


Sign in / Sign up

Export Citation Format

Share Document