Synthesis Mechanism of Flame Synthesized Deformity Carbon Nanotubes

2011 ◽  
Vol 688 ◽  
pp. 122-126
Author(s):  
Zhao Yong Ding ◽  
Bao Min Sun ◽  
Yong Hong Guo ◽  
Bin Jia ◽  
Xiao Lian Ding
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Iron Pentacarbonyl ◽  
Synthesis Mechanism ◽  
Atom Clusters ◽  
Transmission Electron ◽  
High Degree ◽  
Scanning Electron

Pyramid shaped pyrolysis flame is a new method to synthesis carbon nanotubes (CNTs). Oxy-acetylene flame was used as the source of heat, CO as the source of carbon, and iron pentacarbonyl (Fe(CO)5) as the source of catalyst. Field emission scanning electron microscope (FE-SEM) and High resolution transmission electron microscopy (HR-TEM) were used to illustrate the experimental results. Our results show straight, uniform and high degree graphitization CNTs were produced whereas lots of deformity tubes were present, as bamboo-shaped tubes, filled tubes, diameter changed tubes, irregular tubes, etc. In order to understand the synthesis mechanism of deformity tube, many models were presented for the different shape tubes. Synthesizing bamboo-shaped tubes maybe decide by capillary siphon and the low melting state of catalyst particles. Besides capillary siphon and the low melting state of catalyst particles, filled tubes mainly connect with the continuous supply of catalyst atom clusters. The diameter changed tubes maybe influenced by the diameter changing of catalyst particles and the action of other materials. Irregular tubes maybe affect by temperature and other factors.

Preparation and Characterization of Monodisperse Ceria Microspheres

2010 ◽  
Vol 434-435 ◽  
pp. 850-852
Author(s):  
Qi Wang ◽  
Bo Yin ◽  
Zhen Wang ◽  
Gen Li Shen ◽  
Yun Fa Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Electron Microscope ◽  
Crystalline Form ◽  
X Ray ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Scanning Electron

In present work, ceria microspheres were synthesized by template hydrothermal method. Crystalline form of the as-synthesized ceria microspheres was defined by X-ray powder diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Dispersibility of ceria microspheres was comprehensively characterized using scanning electron microscope (SEM) observation and laser particle size analyzer. Furthermore, the ultraviolet light absorption performances of ceria microspheres with several different sizes were compared by ultraviolet visible spectrophotometer. The results showed that ceria microspheres presented excellent UV absorbent property and the size influence was remarkable.

Morphology and thermal properties of nanocomposites based on chiral poly(ester-imide) matrix reinforced by vitamin B1 functionalized multiwalled carbon nanotubes

2016 ◽  
Vol 51 (16) ◽  
pp. 2291-2300 ◽  
Author(s):  
Shadpour Mallakpour ◽  
Samaneh Soltanian
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Multiwalled Carbon Nanotubes ◽  
Vitamin B1 ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Scanning Electron

Chemical functionalization of carboxylated multiwalled carbon nanotubes with vitamin B1 was carried out under ultrasonic irradiation. The functionalized nanotubes were embedded in a chiral and biodegradable poly(ester-imide) to prepare multiwalled carbon nanotubes reinforced polymer nanocomposites. Optically active poly(ester-imide) was synthesized by step-growth polymerization of aromatic diol and amino acid based diacid. The vitamin B1 functionalized multiwalled carbon nanotubes and the resulting nanocomposites were examined using Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, transmission electron microscopy, and field-emission scanning electron microscopy. Thermogravimetric analysis results indicated that temperature at 10% weight loss was increased from 409℃ for pure PEI to 419℃, 427℃, and 430℃ for nanocomposites containing 5%, 10%, and 15% functionalized multiwalled carbon nanotubes, respectively. The Fourier-transform scanning electron microscopy and transmission electron microscopy images exhibited that the functionalized multiwalled carbon nanotubes were separated individually and enwrapped by polymer chains.

STEM (Scanning Transmission Electron Microscopy) in a SEM (Scanning Electron Microscope) for Failure Analysis and Metrology

2002 ◽  
Author(s):  
William E. Vanderlinde
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Material Structure ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron ◽  
Thin Samples

Abstract Recent developments in transmission electron microscopy (TEM) sample preparation have greatly reduced the time and cost for preparing thin samples. In this paper, a method is demonstrated for viewing thin samples in transmission in an unmodified scanning electron microscope (SEM) using an easily constructed sample holder. Although not a substitute for true TEM analysis, this method allows for spatial resolution that is superior to typical SEM imaging and provides image contrast from material structure that is typical of TEM images. Furthermore, the method can produce extremely high resolution x-ray maps that are typically produced only by scanning transmission electron microscope (STEM) systems.

Electron Tomography of HEK293T Cells Using Scanning Electron Microscope–Based Scanning Transmission Electron Microscopy

2012 ◽  
Vol 18 (5) ◽  
pp. 1037-1042 ◽  
Author(s):  
Yun-Wen You ◽  
Hsun-Yun Chang ◽  
Hua-Yang Liao ◽  
Wei-Lun Kao ◽  
Guo-Ji Yen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Scanning Transmission Electron Microscopy ◽  
Electron Tomography ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
3D Volume ◽  
Scanning Electron

AbstractBased on a scanning electron microscope operated at 30 kV with a homemade specimen holder and a multiangle solid-state detector behind the sample, low-kV scanning transmission electron microscopy (STEM) is presented with subsequent electron tomography for three-dimensional (3D) volume structure. Because of the low acceleration voltage, the stronger electron-atom scattering leads to a stronger contrast in the resulting image than standard TEM, especially for light elements. Furthermore, the low-kV STEM yields less radiation damage to the specimen, hence the structure can be preserved. In this work, two-dimensional STEM images of a 1-μm-thick cell section with projection angles between ±50° were collected, and the 3D volume structure was reconstructed using the simultaneous iterative reconstructive technique algorithm with the TomoJ plugin for ImageJ, which are both public domain software. Furthermore, the cross-sectional structure was obtained with the Volume Viewer plugin in ImageJ. Although the tilting angle is constrained and limits the resulting structural resolution, slicing the reconstructed volume generated the depth profile of the thick specimen with sufficient resolution to examine cellular uptake of Au nanoparticles, and the final position of these nanoparticles inside the cell was imaged.

Paraliomyces lentiferus: an ultrastructural study of a little-known marine ascomycete

1992 ◽  
Vol 70 (11) ◽  
pp. 2223-2232 ◽  
Author(s):  
S. J. Read ◽  
S.-Y. Hsieh ◽  
E. B. G. Jones ◽  
S. T. Moss ◽  
H. S. Chang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Ultrastructural Study ◽  
Republic Of China ◽  
Mucilaginous Sheath ◽  
Transmission Electron ◽  
Scanning Electron

A collection of Paraliomyces lentiferus from Taiwan, Republic of China, is compared with that of the type description and examined at both scanning and transmission electron microscope levels as part of our review of the taxonomy of the marine Ascomycotina. Particular attention was devoted to the structure of the ascospore appendage. The ascospore wall comprises a mesosporium, an episporium, and a mucilaginous sheath (exosporium?) In addition, there is a single, gelatinous, lateral appendage adjacent to the central septum. The appendage comprises electron-opaque fibrils that in immature ascospores are connected to the ascospore wall via fine electron-opaque strands and larger electron-opaque aggregates of material. The origin of the appendage is discussed. Key words: ascospore, attachment, marine ascomycete, scanning electron microscopy, spore appendage, transmission electron microscopy.

Fabrication of a vertically aligned carbon nanotube electrode and its modification by nanostructured MnO2 for supercapacitors

2009 ◽  
Vol 81 (12) ◽  
pp. 2317-2325 ◽  
Author(s):  
Wei-De Zhang ◽  
Jin Chen
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Strongly bonded arrays of vertically aligned, multi-walled carbon nanotubes (MWNTs) have been successfully grown on Ta foils, and provide a convenient basis for fabricating electrodes with high conductivity and stability. The MWNT arrays were further coated by nanostructured MnO2 through reacting with KMnO4 solution at room temperature. The morphology of the MnO2/MWNT nanocomposite was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the MnO2 is a beehive-like nanostructure that is homogeneously and densely coated on the surface of the MWNTs. The capacitance of the MWNT electrode was significantly increased from 0.14 to 6.81 mF cm–2 after being modified with nanostructured MnO2, that is, the mass-specific capacitance of the bare and MnO2-modified MWNTs was about 33 and 446 F g–1, respectively. The MnO2/MWNT nanocomposite on Ta foils could be potential for developing a supercapacitor.

The distribution and fine structure of the integumentary papillae of the cercaria ofHimasthla secunda(Nicoll)

Parasitology ◽  
1970 ◽  
Vol 61 (2) ◽  
pp. 219-227 ◽  
Author(s):  
H. D. Chapman ◽  
R. A. Wilson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Spatial Distribution ◽  
Fine Structure ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Silver Nitrate ◽  
Light Microscope ◽  
Transmission Electron ◽  
Scanning Electron

The distribution of the integumentary papillae of the cercaria ofHimasthla secundahas been studied by a variety of techniques. Structures stained by silver nitrate and visible under the light microscope correspond in their spatial distribution with papillae observed under the scanning electron microscope. The tegumentary papillae described with the light and scanning electron microscope are correlated with the specialized nerve endings in the tegument as seen in transmission electron microscopy. The ultrastructure of these papillae is examined by conventional transmission electron microscopy and the probability that these structures are sensory is discussed.

Ultrastructural studies on conidiomata, conidiophores, and conidiogenous cells in six lichen-forming Ascomycetes

1984 ◽  
Vol 62 (10) ◽  
pp. 2081-2093 ◽  
Author(s):  
Rosmarie Honegger
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Transmission Electron Microscope ◽  
Developmental Studies ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Conidium Formation ◽  
Scanning Electron

The conidiomata, conidiophores, and conidia of six lichen-forming Ascomycetes were investigated using the scanning electron microscope, and conidium development in two of these species was studied by transmission electron microscopy. Phialidic (micro) conidium formation was observed in the mycobiont of Parmelia tiliacea, Physconia pulverulacea, and Cladonia furcata (Lecanorales), in Lobaria laetevirens (Peltigerales), and in Caloplaca aurantia (Teloschistales). Annellations, first described by Vobis on the basis of light and transmission electron microscope investigations, were also found in scanning electron microscope preparations of macroconidia bearing conidiogenous cells of Lecanactis abietina (Opegraphales). Ultrastructural and developmental studies on conidiophore structure and conidium formation may be of interest for taxonomic and evolutionary considerations in lichen-forming fungi.

scholarly journals Crystallography of Growth Blocks in Spheroidal Graphite

2018 ◽  
Vol 925 ◽  
pp. 54-61 ◽  
Author(s):  
Etienne Brodu ◽  
Emmanuel Bouzy ◽  
Jean Jacques Fundenberger ◽  
Benoit Beausir ◽  
Lydia Laffont ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Electron Backscatter Diffraction ◽  
Spheroidal Graphite ◽  
Transmission Electron ◽  
Competition Process ◽  
Graphite Growth ◽  
Scanning Electron

A better understanding of spheroidal graphite growth is expected in a near future thanks to widespread use of transmission electron microscopy. However, common transmission electron microscopy is quite time consuming and new indexing techniques are being developed, among them is transmission Kikuchi diffraction in a scanning electron microscope, a recent technique derived from electron backscatter diffraction. In the present work, on-axis transmission Kikuchi diffraction in scanning electron microscope, completed by transmission electron microscopy, was used with the objective of producing new observations on the microstructure of spheroidal graphite. This study shows that disorientations between blocks and sectors in spheroidal graphite are quite large in the early growth stage, which may be indicative of a competition process selecting the best orientations for achieving radial growth along thecdirection of graphite.

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