Structural Characterization of Mullite-Based Ceramic Material from Al2O3 and Silica Xerogel Converted from Sago Waste Ash

2013 ◽  
Vol 789 ◽  
pp. 262-268
Author(s):  
Haji Aripin ◽  
Seitaro Mitsudo ◽  
Endangsusilowati S. Prima ◽  
Inyoman Nyoman Sudiana ◽  
Hikamitsu Kikuchi ◽  
...  

In this investigation, mullite ceramics were produced by mixing Al2O3and amorphous silica xerogel (SX) extracted from sago waste ash. The composition was prepared by adding an amount from 0 to 80 mol% of Al2O3into SX. The samples were dry pressed and sintered in the temperature range between 900°C and 1200°C. Their properties have been characterized on the basis of the experimental data obtained using thermal analysis (DSC/TGA, X-ray diffraction and scanning electron microscopy (SEM). The results show that two major differences become obvious when comparing the samples loaded by the smaller and larger amount of Al2O3. First, cristobalite formation is retarded in the sample loaded by the larger amount of Al2O3. Second, at 1200°C, the observed volume fraction of mullite is higher in the sample loaded by the larger amount of Al2O3. The DSC analysis indicates that the mullite crystallization takes place at 1200°C for 60 mol% Al2O3loaded SX sample as confirmed by the XRD pattern. It was found that there was not a complete reaction of mulitization for sample sintered up to 1200°C.

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.


2019 ◽  
Vol 20 (1) ◽  
pp. 11
Author(s):  
A.A. Made Wisnu Wijaya Putra ◽  
W. G. Suharta ◽  
P. Suardana

Superconductor Y-247 (Y2Ba4Cu7O15-?) with adding silver (Ag) by using the wet-mixing method has been done. The synthesis process was carried out by calcination at 600o C for 3 hours and sintered at 925o C for 10 hours. Variations in the increase in the addition of Ag used were Ag0.05, Ag0.1, Ag0.15 and Ag0.2. Characterization of X-Ray Diffraction (XRD), showed an increase in the addition of Ag resulting in a decrease in the volume fraction, where the volume fractions obtained consecutive were 55.0%, 51.3%, 50.9% and 46.3%. Increasing the addition of Ag results in an increase in the lattice parameter values in the direction of the a axis which is 3.8247 Å, 3.8291 Å, 3.8292 Å, 3.8293 Å, decreasing the lattice parameter values in the b axis direction which is 3.8426 Å, 3.8415 Å, 3.8409 Å, 3.8383 Å and decreasing the lattice parameter values in the direction of the c axis are 49.2174 Å, 49.2022 Å, 49.1881 Å, 49.1761 Å. Analysis of the results of the characterization of Scanning Electron Microscopy (SEM), the particle size obtained was 225.47 nm, 202.88 nm, 190.68 nm and 172.22 nm.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


2012 ◽  
Vol 620 ◽  
pp. 314-319
Author(s):  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
Saadah Abdul Rahman

Hardwood is wood from angiosperm trees. The characteristic of hardwood include flowers, endosperm within seeds and the production of fruits that contain the seeds. This paper aims to discuss the preparation and characterization of cellulose obtained from hardwood. The hardwood Merbau (Intsia bijuga) was chosen as raw material in this study. Alkaline treatment and delignification methods were used for the preparation of cellulose. Acid hydrolysis was employed to produce cellulose nanocrystal (CNC). The treated and untreated samples were characterized using x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The final product, from both trated and untreated samples were then compared.


1989 ◽  
Vol 4 (6) ◽  
pp. 1320-1325 ◽  
Author(s):  
Q. X. Jia ◽  
W. A. Anderson

Effects of hydrofluoric acid (HF) treatment on the properties of Y–Ba–Cu–O oxides were investigated. No obvious etching of bulk Y–Ba–Cu–O and no degradation of zero resistance temperature were observed even though the oxides were placed into 49% HF solution for up to 20 h. Surface passivation of Y–Ba–Cu–O due to HF immersion was verified by subsequent immersion of Y–Ba–Cu–O in water. A thin layer of amorphous fluoride formed on the surface of the Y–Ba–Cu–O during HF treatment, which limited further reaction between Y–Ba–Cu–O and HF, and later reaction with water. Thin film Y–Ba–Cu–O was passivated by HF vapors and showed no degradation in Tc-zero after 30 min immersion in water. The properties of the surface layer of Y–Ba–Cu–O oxide after HF treatment are reported from Auger electron spectroscopy, x-ray diffraction, and scanning electron microscopy studies.


2021 ◽  
pp. 004051752110154
Author(s):  
Zhihui Qin ◽  
Shuyuan Zhao ◽  
Liu Liu ◽  
Zhaohe Shi ◽  
Longdi Cheng ◽  
...  

Degumming is the dominant method for insolating lignocellulosic fibers in textile applications. Traditional alkaline degumming (TAL), as a common method, requires a high-concentration alkali and has been a severe challenge to the environment. In the research reported here, the possibility of innovative jute degumming by organic solvents 1-2 propylene glycol and a combination of additive green oxygen (GO-OS) was studied. The results revealed that fibers could be extracted by this system (under condition of 0.9% GO-OS, 180°C, 120 min), and obtained fibers with higher breaking tenacity (7.1 cN/dtex), yield (65.7%), breaking elongation (2.87%) and residual gum (11.7%), which all meet the requirement of the relevant Chinese Textile National Standards. Notably, the required reaction time (120 min) of the GO-OS system was 180 min shorter than that of the TAL method. Furthermore, the modifications introduced by the degumming effect on physicochemical aspects were characterized and confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. This study provides a promising degumming method for separating jute lignocellulose without acid and alkali consumption.


2022 ◽  
Vol 321 ◽  
pp. 126326
Author(s):  
Gladis Aparecida Galindo Reisemberger de Souza ◽  
Ramón Sigifredo Cortés Paredes ◽  
Frieda Saicla Barros ◽  
Gustavo Bavaresco Sucharski ◽  
Sebastião Ribeiro Junior ◽  
...  

2016 ◽  
Vol 34 (2) ◽  
pp. 412-417
Author(s):  
Esra Öztürk

AbstractIn this work, aluminate type phosphorescence materials were synthesized via the solid state reaction method and the photoluminescence (PL) properties, including excitation and emission bands, were investigated considering the effect of trace amounts of activator (Eu3+) and co-activator (Dy3+). The estimated thermal behavior of the samples at certain temperatures (> 1000 °C) during heat treatment was characterized by differential thermal analysis (DTA) and thermogravimetry (TG). The possible phase formation was characterized by X-ray diffraction (XRD). The morphological characterization of the samples was performed by scanning electron microscopy (SEM). The PL analysis of three samples showed maximum emission bands at around 610 nm, and additionally near 589 nm, 648 nm and 695 nm. The bands were attributed to typical transitions of the Eu3+ ions.


Sign in / Sign up

Export Citation Format

Share Document