Spectroscopic analysis of chemically modified carbon fibres

2021 ◽  
Author(s):  
Álvaro Gustavo de Oliveira Moraes ◽  
Micheli de Souza Haack ◽  
Mirabel Cerqueira Rezende ◽  
Sandro Campos Amico
Keyword(s):  
Spectroscopic Analysis ◽  
Carbon Fibres ◽  
Chemically Modified

Investigation of an Elastomer Composite with Modified Carbon Fibres

2016 ◽  
Vol 43 (12) ◽  
pp. 9-12
Author(s):  
O.E. Maskalyunaite ◽  
S.Yu. Zabolotskikh ◽  
V.V. Nekrasova ◽  
P.N. Grakovich ◽  
L.F. Ivanov ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Plasma Modification ◽  
Carbon Fibres ◽  
Organofluorine Compounds ◽  
Chemically Modified ◽  
Compression Set ◽  
Main Fraction ◽  
Different Types ◽  
Elastomer Composites ◽  
Positive Results

The possibility of using ‘Belum’ chemically modified hydroxycellulose carbon fibres (CFs) to improve the wear resistance of elastomer composites was studied. Comminuted Belum fibres with a length of the main fraction of 50–100 μm were used. Chemical modification of the CFs was carried out in electric discharge plasma in a medium of organofluorine compounds, as a result of which prepolymer coatings were formed with a thickness of several tens of nanometres, similar in chemical composition to polyetrafluoroethylene. The microstructure of the modified CFs was investigated by electron microscopy. It was shown that the introduction of modified Belum-grade CFs leads to an increase in the wear resistance of elastomer composites based on SKF-26 fluorine-containing rubber. It was also shown that there is an improvement in the ageing resistance, measured from the change in 20% compression set at temperatures of 100, 125, 150, and 200°C. Comparative bench tests revealed considerable advantages of different types of moving seal manufactured using modified Belum CFs. Service tests of articles manufactured from rubbers of the experimental composition also showed positive results. The mechanism of the influence of plasma modification is discussed.

AC-Impedance Spectroscopic Analysis on the Charge Transport in CVD-Grown Graphene Devices with Chemically Modified Substrates

2016 ◽  
Vol 8 (41) ◽  
pp. 27421-27425 ◽  
Author(s):  
Bok Ki Min ◽  
Seong K. Kim ◽  
Seong Ho Kim ◽  
Min-A Kang ◽  
Suttinart Noothongkaew ◽  
...  
Keyword(s):  
Charge Transport ◽  
Spectroscopic Analysis ◽  
Ac Impedance ◽  
Chemically Modified ◽  
Grown Graphene ◽  
Graphene Devices

Surface spectroscopic analysis of vapour grown carbon fibres prepared under various conditions

Carbon ◽  
1998 ◽  
Vol 36 (7-8) ◽  
pp. 1183-1190 ◽  
Author(s):  
Hans Darmstadt ◽  
Christian Roy ◽  
Serge Kaliaguine ◽  
Jyh-Ming Ting ◽  
Robert L. Alig
Keyword(s):  
Spectroscopic Analysis ◽  
Carbon Fibres

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

Elemental analysis of human erythrocytes

1989 ◽  
Vol 47 ◽  
pp. 242-243
Author(s):  
S. A. Livesey ◽  
A. A. del Campo ◽  
E. S. Griffey ◽  
D. Ohlmer ◽  
T. Schifani ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Elemental Analysis ◽  
Human Erythrocyte ◽  
Spectroscopic Analysis ◽  
Model System ◽  
Human Erythrocytes ◽  
List Type ◽  
Chemical Fixation ◽  
Ethanol Dehydration ◽  
Lowicryl K4m

The aim of this study is to compare methods of sample preparation for elemental analysis. The model system which is used is the human erythrocyte. Energy dispersive spectroscopic analysis has been previously reported for cryofixed and cryosectioned erythrocytes. Such work represents the reference point for this study. The use of plastic embedded samples for elemental analysis has also been documented. The work which is presented here is based on human erythrocytes which have been either chemically fixed and embedded or cryofixed and subsequently processed by a variety of techniques which culminated in plastic embedded samples.Heparinized and washed erythrocytes were prepared by the following methods for this study :(1). Chemical fixation in 4% paraformaldehyde/0.25% glutaraldehyde/0.2 M sucrose in 0.1 M Na cacodylate, pH 7.3 for 30 min, followed by ethanol dehydration, infiltration and embedding in Lowicryl K4M at -20° C.

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