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Online since: December 2012
Authors: Qing Tian Li
Study microcosmic structure feature of ceramics water-mouth new materials using electron micro analysis, analyze its effect to mechanical properties, prove big or small crystal grains are the main factor affecting materials, the existing of structure defect can improve fracture toughness of materials.
Sample Preparing Using stable ZrO2 small powder of Al2O3 grain diameter <5µm, electric smelting α-Al2O3 small powder diameter<10µm, pure CaSiO2 and CaO analyzed by chemistry mixing them according to proper proportion, balling etc static forming, under 1520oC-1580oC, sintering 3h, making it into lumps of sample.
According to analysis, in 2# sample the main crystal phase is c-ZrO2 who has a few t-ZrO2. c-ZrO2 has CaF2 type structure, its O2- occupy all the place of four sides body, positive ion is located in close packing (cubic phase) place, in the structure octahedral place is empty, O2- can spread quickly in the crystal.
In ceramics materials structure, air hole is also structure factor which low strength[2], especially the air hole existing on the crystal boundary, it leads to stress focus, may lead to strength of materials drop.
This structure can lead to stress focus in ceramics materials, which make crystal boundary fracture and make the strength of materials drop[3].
Online since: October 2010
Authors: Xiu Jie Jia, Jiang Feng Li, Fang Yi Li
Savageness starch is a kind of polarity strong crystal polymer, there is strong hydrogen bond among molecules, so it has bad thermoplastic. 1.1.3 Froth principle and vesicant Vesicant is the mater to produce much gas (such as N2, CO2, CO) during polymer molding, to make the dishware become much holes structure.
Macromolecule with tiny hole structure possess light weight and sound insulation and heat insulation, better mechanism damp capability with widely usage.
A new method is used water as the froth stuff with sanitation and lower cost. 1.2 The method to produce the slurry The capability of the plant fiber are difference with different method produced, there are many slurry methods for plant fiber: machine produce, thermal machine produce, chemistry produce and thermal chemistry produce.
(3) New technology has been researched and developed of the implicit steam lines, quick exhaust, a new mold with no extra material aim at different structures and types of tableware products, the product with rapid exhaust, it demonstrated molding material to ensure product quality and improving production efficiency
Online since: October 2011
Authors: Ying Jia, Tian Tian Liu, Cheng Luo
Characterization of samples Crystal structure of as-prepared products is characterized by powder X-ray diffraction (XRD) on a D /max-rB X-ray diffractometer with monochromatized Cu Kα (λ = 1.54178 Å) incident radiation.
Results and discussions Structure analysis Fig.2 is the XRD pattern of the synthesized cerium and zirconium composite oxide, as it is shown clearly that the synthesized product is crystal.
The products are characterized by XRD, SEM, TEM, Raman spectra, the result shows that the structure, appearance and optical property of the synthesized Ce0..67Zr0.33O2 exhibit very well. 3.
Materials Chemistry and Physics 101 (2007) 415-422
Materials Chemistry and Physics 107 (2008) 132-136
Online since: December 2019
Authors: Vladimir Kotlyar
In the first stage, which lasts for about a month, the strength gain is due to the formation of crystalline intergrowths of calcium hydroxide, the chemistry of which is formed by the reaction: СаО + Н2О = Са(ОН)2 (1) Then the stage of hardening crystalline intergrowths of calcium hydroxide due to carbonization by carbon dioxide present in the atmosphere by the reaction takes place: Са(ОН)2 + СО2 = СаСО3 + Н2О (2) At the same time, during the carbonization process, chemically bound water is released, therefore, in the first 1-2 years, limestone mortars seem to be wet.
For this, the geological structure of the sampling area (the Republic of Abkhazia) was studied, which showed that various types of limestone used both for lime production and as aggregate were widespread in this area.
At the same time, we made certain assumptions, taking into account the specific confirmed data: - lime for construction was made from the same raw materials (lime stones of the Cretaceous period), which is common in the area of New Athos and close to the sampling sites; - lime was produced according to generally accepted technology, which has been preserved for centuries; - samples were in the same natural conditions (temperature, humidity, amount of carbon dioxide in the air, etc.); - all samples have a porous structure, which does not prevent the access of carbon dioxide and the growth of secondary calcite micro-crystallites; - sampling during X-ray phase analysis was carried out under the same conditions; - marble and other carbonate rocks, in which regular calcite crystals are clearly visible, have the greatest crystallinity of calcite in nature.
The most ancient Anacopian structure is the wall of the citadel.
Fedorov, Physical chemistry of silicates and other refractory compounds.
Online since: April 2017
Authors: Won Youl Choi, Wan Tae Kim
Over the last 40 years, biology, chemistry, electronics, life sciences and other industries to lead active research has been attracting attention.
TiO2 nanotube arrays have a highly-ordered structure and very clean surface.
Meso-porous SiO2 structure has been usually used as an interferometric biosensing chip [9, 10].
Compared with meso-porous SiO2 structure, TiO2 nanotube arrays have some advantages such as a higher performance in high pH solution and lower decrease in Reflective Interferometric Fourier Transform Spectroscopy (RIFTS) peak.
Güthner et al., 7th ed., Guanidine and Derivatives, Ullman's Encyclopedia of Industrial Chemistry, Wiley, 2007 p. 13.
Online since: June 2014
Authors: Mohammed A. Al-Daous, Abdullah F. Al-Ahmadi, Tawfik A. Saleh
Saleh*1,c 1 Department of Chemistry, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia 2 Saudi Aramco R&D center, Dhahran 31311, Saudi Arabia a afahmadi@kfupm.edu.sa, b mdaous@kfupm.edu.sa, c* tawfik@kfupm.edu.sa Keywords: Carbon nanosphere, Polymethylmethacrylate, temperature, morphology Abstract.
Carbon can bond in other different ways to create structures with dissimilar properties, for example, carbon nanotubes and carbon nanofiber have the filamentous arrange of graphene sheets.
Figure 1 SEM images of the surface structure of the the prepared carbon nanosphere at (a) 220 oC (b) 250 oC (c) 280 oC & (d) 300 oC Results and Discussion Scanning electron microscopy of the final samples prepared at various calcination temperatures showed the formation of carbon shells.
Carbon spheres 250 oC shows less disordered graphite layers and more crystalline structure.
Acknowledgments Authors acknowledge the support of Chemistry department, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia for this work.
Online since: May 2011
Authors: Xian Hui Sun, Yong Sheng Ma
The properties of resulting graft copolymer may be widely controlled by the characteristics of the side chains, including molecular structure, length, and number.
Results and Discussion Physical Chemistry Performance of Resultant Product.
It was shown by the SEM (Fig.1) that hand sheet section pulp fiber structure of control sample without adding graft copolymer was incompact,section fibers were pell-mell and longer.
It was shown by the SEM(Fig.2)that sheet section fiber structure of pulp with adding graft copolymer was compact, section fibers were shorter.
Resultant product that had stable physical chemistry performance had more outstanding dry-strengthening effect to wood pulp than unmodified gelatin.
Online since: June 2016
Authors: Satriawan Dini Hariyanto, Gunawan Setia Prihandana, Tutik Sriani
Hydroxyapatite (HA) has attracted wide interest in modern material chemistry due to its outstanding biocompatibility, environmental friendly nature, and it’s porosity which is a crucial factor in adsorption process [6-9,13-15].
This phenomenon results in forming microporous structure on HA disc surface, consists of long grains with circular shape on the top which is similar to the structure of coral reef.
This microporous structure is the form that is needed for heavy metal filtration.
El-Anadouli, Efficient treatment of lead-containing wastewater by hydroxyapatite/chitosan nanostructures, Arabian Journal of Chemistry (2015) xxx, xxx–xxx
Online since: May 2021
Authors: A.A. Yusupova, L.R. Baraeva, A.A. Bobrishev
Composition number Component Content, wt-% Sulfur cake Sulfur Zinc chloride 1 100 – – 2 90 10 – 3 80 20 – 4 99 – 1 5 89 10 1 6 79 20 1 To create a dense non-porous structure and increase the physicomechanical characteristics of the samples, the method of hot pressing of samples was applied (Fig. 3).
The developed materials can be used for the construction and repair of industrial buildings and structures, protective coatings, for the creation of pavements (tiles, paving stones) for the arrangement of park areas or indoor and outdoor utility rooms [18-21].
Makarovskikha, Ash and Slag Waste as a Secondary Raw Material, Procedia Chemistry 10 (2014) 184-191
Kalinkin, Structure and properties of modified sulfur binder, Building materials. 7 (2005) 6-9
Aleskovsky, Quantum synthesis, Russian Journal of Applied Chemistry, Volume 11 (2007) 1761-1767
Online since: August 2018
Authors: Yue Liu, Jie Guang Song, Yue Ning Qin, Yun Xiang, Xi Ling Zhang, Lin Chen, Songlin Guo, Song Lin Guo
Effect of Sintering Temperature on the Densification Mechanism of Al2O3-Al Metal Ceramics via the Powder Metallurgy Method Jieguang Song1,2,a, Lin Chen2, Yun Xiang2, Yue Liu2, Xinshuang Guo2, Xiling Zhang2, Songlin Guo1, Yuening Qin3,b 1Engineering & Technology Research Center for Environmental Protection Materials and Equipment of Jiangxi Province, School of Materials and Chemistry Engineering, Pingxiang University, Pingxiang 337055 China 2Key Laboratory for Industrial Ceramics of Jiangxi Province, School of Materials and Chemistry Engineering, Pingxiang University, Pingxiang 337055 China 3Xiangsihu College of Guangxi University for Nationalities, Nanning 530008 China asjg825@163.com, b274023049 @qq.com Keywords: Metal ceramics; sintered temperature, densification mechanism, powder metallurgy method Abstract.
After the sample after sintering, finished with analyzing balance measure the density, take a small piece, sonication and dried after treatment were sprayed gold, followed by SEM observation of the interface structure, the process flow diagram is shown in Fig.1.
Al content in the case of sufficiently high can wrap Al2O3 to form a more continuous distribution block, which results in a higher density of the organizational structure.
Wang, Study of the preparation of γ-Al2O3 nanostructured hierarchical hollow microspheres with a simple hydrothermal synthesis using methylene blue as structure directing agent and their adsorption enhancement for the dye, Chem.