Preparation and Structural Characterization of CMC/MMT Nanocomposite

2010 ◽  
Vol 177 ◽  
pp. 606-609
Author(s):  
Chuan Xin Zhai ◽  
Yan Li ◽  
Xiang Dong Ma ◽  
Shi Zhong Wei ◽  
Liu Jie Xu

Using montmorillonite (MMT) and sodium carboxymethylcellulose (CMC) as raw materials, CMC/MMT nanocomposites were prepared by the solution intercalation technique. The microstructures of MMT before and after being intercalated were characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). The results of XRD showed that when the adding amount of CMC increased from naught to 70wt%, the structures of MMT have no change basically; when the adding amount of CMC increased to 80wt%, the decrease of MMT (001) was significant; when the adding amount of CMC reached to 90wt%, the diffraction peak of (001) disappeared, which indicated that the layers of MMT have been exfoliated along (001) and the CMC/MMT intercalated structure has been obtained. The observations by HRTEM showed that the shapes of MMT are layer aggregation or agglomerated particles. The MMT added with 90wt% CMC has changed into intercalated structure with alternating MMT and CMC order mainly, and the intercalated structure was characterized at the atomic scale.

2013 ◽  
Vol 6 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Abdulmula Ali Albhilil ◽  
Martin Palou ◽  
Jana Kozánková

Abstract Series of six cordierite-mullite ceramics were synthesized via solid state reaction at various temperatures from 1250 °C for pure cordierite to 1500 °C for pure mullite. Then the samples were submitted to the test of thermal shock resistance based on cycling heating-quenching procedure. X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Mercury intrusion porosimeter (MIP) have been used to characterize the samples before and after cycling heating-quenching method. Sample 6 was broken after 35 heating-quenching cycles, while the five other reminded stable. The refractoriness of samples is found to be higher than that of commercial ones. XRD shows that heating-quenching procedure has led to crystallization of cordierite and mullite phases. Apart from sample 6, the pore structure is stable with slight consolidation. The microstructure images confirm the results of XRD and MIP showing crack in sample 6 only, but compact and larger particles resulting from crystal growth in other samples due to the repeated action of heating.


2012 ◽  
Vol 624 ◽  
pp. 59-62 ◽  
Author(s):  
Cai Xia Li ◽  
Jun Guo ◽  
Danyu Jiang ◽  
Qiang Li

In this paper, employing Cu(AC)2•H2O, SnCl2•2H2O and thiourea as raw materials, the composites of graphene/Cu2SnS3 quantum dots (QDs) were prepared simply and quickly using the hydrothermal method. Meanwhile, the separate Cu2SnS3 QDs were also synthesized in the same way. The as-obtained Cu2SnS3 QDs and composites’ phase structures were analyzed and characterized by powder X-ray diffraction (XRD), and the results indicated that the size of the Cu2SnS3 QDs in the composites were less than that of the separate Cu2SnS3 QDs. At the same time, their morphologies were also observed and cross-confirmed by Transmission Electron Microscopy (TEM), and the measurements manifested that Cu2SnS3 QDs were uniformly dispersed on the surface of the graphene, while the separate Cu2SnS3 QDs have obvious glomeration. In addition to this, elemental analysis was also made to verify the existence of Cu2SnS3 on the surface of graphene.


2013 ◽  
Vol 544 ◽  
pp. 21-24
Author(s):  
Cai Xia Li ◽  
Lin Zhang ◽  
Dan Yu Jiang ◽  
Qiang Li

Selecting graphene oxide (GO) and the Degussa P25 TiO2 (80% anatase and 20% rutile) as raw materials, the composites of graphene/TiO2 nano-tubes were simply and quickly prepared under the conditions of a concentrated solution of sodium hydroxide. The as-obtained composites’ phase structure was analyzed and characterized by powder X-ray diffraction (XRD), their morphologies were also observed and cross-confirmed under the Transmission Electron Microscopy (TEM). The measurements showed that the composites prepared in this work have a remarkable structure, and compared to the seperate TiO2 nano-tubes, the agglomeration of TiO2 nano-tubes covered on the surface of the graphene is apparently not so serious. In view of this, we preliminary tested the composites’ photo-catalytic performance with the visible light irradiation, and also made a comparison with TiO2 nano-tubes.


1992 ◽  
Vol 268 ◽  
Author(s):  
G.P. Chambers ◽  
G. K. Hubler ◽  
J.A. Sprague ◽  
K.S. Grabowski

ABSTRACTThin Ti films have been bombarded at room temperature with 350–500 eV deuterium ions at current densities up to 0.5 mA/cm2. Analysis using scanning electron microscopy, x-ray diffraction, transmission electron microscopy, and secondary ion mass spectroscopy were carried out before and after bombardment. It was determined that deuterium diffuses rapidly throughout the Ti film, that the films were in a state of high compressive stress, and that the TiD2 phase was formed. No evidence of deuterium gas bubbles was found.


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.


1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


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.


2017 ◽  
Vol 8 ◽  
pp. 1257-1265 ◽  
Author(s):  
Urszula Klekotka ◽  
Magdalena Rogowska ◽  
Dariusz Satuła ◽  
Beata Kalska-Szostko

Ferrite nanoparticles with nominal composition Me0.5Fe2.5O4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11–16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with –COOH and –NH2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).


2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.


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