scholarly journals SYNTHESIS OF CARBON NANOFIBERS BASED ON HUMIC ACID AND POLYACRYONITRILE BY ELECTROSPINNING METHOD

2021 ◽  
Vol 447 (3) ◽  
pp. 103-110
Author(s):  
B.T. Yermagambet ◽  
M.K. Kazankapova ◽  
A.T. Nauryzbayeva ◽  
Zh.M. Kassenova
Keyword(s):  
Electron Microscopy ◽  
Humic Acid ◽  
Elemental Composition ◽  
Carbon Nanofibers ◽  
Carbon Fibers ◽  
X Ray ◽  
Electrospinning Method ◽  
Original Product ◽  
Degree Of Graphitization ◽  
Scanning Electron

The article describes a method for obtaining carbon nanofibers (CNFs) based on humic acid from oxidized coal of the Maikuben basin and polycarlonitrile (PAN) by electrospinning in laboratory conditions. The value of the interelectrode voltage was 20-25 kV. The elemental composition was determined and the surface morphology of the studied sample was studied, the type of modification of the carbon fiber was revealed. As a result of energy dispersive X-ray spectroscopy and scanning electron microscopy (SEM), the chemical composition of the initial CNF (C-48.73%) and the diameter of carbon fibers, which ranged from 148.6 nm to 1.36 μm, were found. The processes of oxidation and carbonization of the obtained samples were also carried out. The elemental composition of carbon after oxidation and carbonization was 87.75 and 89.16%, respectively, the diameter of the fibers was 117.5 nm -1.03 microns. The results of Raman scattering of light (RS) of carbonized CNF showed the degree of graphitization - 23.97%, the ratio I (D) / I (G) = 0.7, I (G) / I (D) = 1.4. The resistance of this material was 27 ohms. On the basis of SEM patterns of CNFs based on humic acid and PAN, it was found that the structure of the sample after oxidation and carbonization retains the original fibrous structure. It was also found that the diameter of nanofibers decreases from 1 μm to 117.5 nm, which may be associated with the release of volatile and heterogeneous components of the original product and the formation of a more structural thin porous filament.

Field-Emission Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis to Understand the Role of Tannin-Based Dyes in the Degradation of Historical Wool Textiles

2014 ◽  
Vol 20 (5) ◽  
pp. 1534-1543 ◽  
Author(s):  
Annalaura Restivo ◽  
Ilaria Degano ◽  
Erika Ribechini ◽  
Josefina Pérez-Arantegui ◽  
Maria Perla Colombini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Composition ◽  
Field Emission ◽  
Cross Sections ◽  
Morphological Changes ◽  
Energy Dispersive ◽  
X Ray ◽  
Edx Analysis ◽  
Scanning Electron

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.

Study of the Surface Morphology and the Microstructure of PAN-Based Carbon Fibers

2011 ◽  
Vol 239-242 ◽  
pp. 1279-1282
Author(s):  
Xue Jun Zhang ◽  
Zan Han ◽  
Yan Hong Tian ◽  
Yan Feng Yang
Keyword(s):  
Electron Microscopy ◽  
Carbon Fibers ◽  
Interlayer Spacing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Graphite Crystallite ◽  
Crystallite Sizes ◽  
Degree Of Graphitization ◽  
Better Than

The microstructure of two kinds of self-made PAN-based high-modulus carbon fibers (HMCF-1, HMCF-2) was studied by scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM), and was compared with that of T800 and M55J. The correlation of XRD and HRTEM in terms of graphite crystallite sizes and interlayer spacing of graphite layer was also investigated. The results show that the diameters of T800, HMCF-1 and HMCF-2 are almost the same (~5.20μm) and all of them are lager than that of M55J (~4.86μm). The crystal sizes and the degree of graphitization are in the order of HMCF-2>HMCF-1>M55J>T800, while the regularity of the lattice fringes of HMCF-2 is better than those of others.

Methanol Sensing Properties of Electrospun SnO2 -ZnO Nanofibers

2011 ◽  
Vol 356-360 ◽  
pp. 565-568
Author(s):  
Shao Hong Wei ◽  
Mei Hua Zhou ◽  
Wei Ping Du
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
Promoting Effect ◽  
Heterojunction Structure ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Electrospinning Method ◽  
Zno Nanofibers ◽  
Scanning Electron

Pure ZnO and SnO2-ZnO nanofibers were synthesized by electrospinning method and characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and methanol sensing properties of these fibers were investigated. The results indicate that the 20 wt% SnO2-ZnO sensor exhibits considerable sensitivity, rapid response, and good selectivity against methanol at 200 °C due to the special 1D fibers properties and the promoting effect of SnO2/ZnO heterojunction structure. The methanol sensing mechanism of SnO2-ZnO nanofibers were also discussed.

Method for synthesizing ZnO of different nanostructures by electrospinning and study of their gas sensing properties

2019 ◽  
Vol 33 (25) ◽  
pp. 1950297
Author(s):  
Xiang-Bing Li ◽  
Shu-Yi Ma ◽  
Fu-Rong Li ◽  
Yu-Xiang Zhao ◽  
Xiao-Bin Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Component Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Gas Sensing Properties ◽  
Zno Nanofibers ◽  
Scanning Electron

The properties of nanomaterials usually depend on their microstructures, the same material of different microstructures could be used for various applications. However, most devices could only synthesize a single microstructure, so it is meaningful that the different microstructures were synthesized by one method. In our study, electrospinning was applied to fabricate ZnO nanofibers and nanoparticles. In this approach, Zn(Ac)/PVP composite fibers of different component ratio were synthesized by electrospinning method which was subsequently calcined and formed ZnO nanofibers and nanoparticles. The microstructure, chemical composition and gas sensing were investigated with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and WS-60A gas sensing measurement system. The synthesis mechanisms of ZnO nanofibers and nanoparticles were discussed in detail.

Peridial composition of white fructifications in the Trichiales (Perichaena and Dianema)

1977 ◽  
Vol 55 (13) ◽  
pp. 1807-1819 ◽  
Author(s):  
Jean D. Schoknecht ◽  
Harold W. Keller
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Elemental Composition ◽  
X Ray ◽  
Silicon Crystals ◽  
Crystalline Deposits ◽  
Chemical Techniques ◽  
Scanning Electron

The nature of the peridial deposits in the genus Perichaena and in a species of Dianema has been defined by a combination of scanning electron microscopy, x-ray microanalysis, and various chemical techniques. These crystalline deposits in the peridium have proven to be primarily calcium oxalate. Some species of Perichaena and the Dianema also incoiporate silicon crystals on the peridium. The white and non-white phases of different species of Perichaena were compared and found to have similar elemental composition of peridia.

Nanographite Films: Structure and Properties

2016 ◽  
Vol 247 ◽  
pp. 17-23 ◽  
Author(s):  
Yury M. Nikolenko ◽  
Albert M. Ziatdinov
Keyword(s):  
Electron Microscopy ◽  
Carbon Fibers ◽  
Photoelectron Spectroscopy ◽  
Magnetic Characteristics ◽  
Activated Carbon Fibers ◽  
Spectroscopy Data ◽  
Structure And Properties ◽  
X Ray ◽  
Structural Blocks ◽  
Scanning Electron

Nanographite film structures of different morphology have been grown on various substrates using the activated carbon fibers (ACF) as a source of nanographites. As was revealed from the data of Raman spectroscopy, the fabricated films consisted mainly of the same structural blocks as the initial ACF. Scanning electron microscopy was used to study the films morphology. The presence of lengthy zigzag edges in nanographites, which is prerequisite for their nontrivial electronic structure and magnetic characteristics, has been established. The X-ray photoelectron spectroscopy data show the appearance of expressed maxima in the C1s spectra of the films in the usually observable "diffuse" structure of π→π* shake-up satellites, π and π + σ plasmons.

Preparation of Ultrafine Poly(ε-Caprolactone) Fibers Containing Silver Nanoparticles via Electrospinning Method

2011 ◽  
Vol 332-334 ◽  
pp. 1235-1238 ◽  
Author(s):  
Yong Tang Jia ◽  
Qing Qing Liu ◽  
Xiang Ying Zhu
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Average Diameter ◽  
Contact Angles ◽  
Electrospun Fibers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Scanning Electron

Electrospun poly(ε-caprolactone) (PCL) fibers containing silver nanoparticles were successfully prepared from PCL solutions added silver collide. The silver collide were obtained by N, N-dimethylformamide (DMF) reducing silver nitrate (AgNO3). The effects of PCL concentration and the content of silver nanoparticles on composite fibers morphology were characterized by field-emission scanning electron microscopy (FESEM). The existence of Ag nanoparticles on the electrospun fibers was approved by X-Ray diffraction (XRD). Simultaneously, the contact angles of fiber membranes were measured. The results indicated that uniform fibers were obtained when PCL concentration was 9wt%, the average diameter of fiber was significantly decreased as increasing the amount of silver collide, and Ag nanoparticles were successfully incorporated into the PCL fibers.

scholarly journals Электроконтактный материал на основе серебра, дисперсноупроченный оксидами цинка, олова и титана

2020 ◽  
Vol 90 (8) ◽  
pp. 1303
Author(s):  
Г.М. Зеер ◽  
Е.Г. Зеленкова ◽  
А.В. Сидорак ◽  
В.В. Белецкий ◽  
С.В. Николаев ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Zinc Oxide ◽  
Elemental Composition ◽  
Titanium Oxide ◽  
Laboratory Testing ◽  
Solid Phase ◽  
Cadmium Oxide ◽  
X Ray ◽  
Scanning Electron

A new electrocontact materal based on silver has been obtained. The material has been dispersion-strengthened by nanopowders of zinc oxide, stannum oxide and titanium oxide. The microstructure and elemental composition of the phases have been formed at solid-phase sintering and electroerosion tests have been studied by the methods of scanning electron microscopy and energy-dispersive X-ray spectroscopy. The electroerosion wear and transitional resistivity have been determined as a result of laboratory testing. The developed electrocontact materal has demonstrated physical, mechanical and exploitational properties similar to the properties of an electrocontact materal based on toxic cadmium oxide

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