scholarly journals Electrochemical Activity and Damage of Single Carbon Fiber

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1758
Author(s):  
Xiaodong Chen ◽  
Chi Zhang ◽  
Guang-Ling Song ◽  
Dajiang Zheng ◽  
Yang Guo ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Anodic Polarization ◽  
Cathodic Polarization ◽  
Fiber Surface ◽  
Electrochemical Activity ◽  
Potential Range ◽  
Polarization Current ◽  
Nacl Solution ◽  
Covalent Bonds ◽  
Current Densities

The electrochemical activity of a carbon fiber was characterized at different potentials in 3.5 wt.% NaCl solution, and the fiber cylindrical surface changed by polarization at different potentials was revealed by SEM, AFM, optical microscopy, FTIR spectroscopy, Raman spectroscopy, and XRD. The results showed that the carbon fiber exhibited different electrochemical activities at some polarization potentials; within a 3V potential range the anodic and cathodic polarization current densities stepped up by more than 5 orders of magnitude, and the carbon fiber (CF) surface dramatically changed with time. Strong anodic polarization appeared to facilitate the breakdown of C-C covalent bonds in the carbon fiber and enhance the amorphization of the fiber surface.

scholarly journals Electrochemical behavior of AgCu50 in alkaline media in the presence of chlorides and 2-mercaptobenzothiazole

2017 ◽  
Vol 53 (3) ◽  
pp. 349-356 ◽  
Author(s):  
V. Grekulovic ◽  
M. Rajcic-Vujasinovic ◽  
A. Mitovski
Keyword(s):  
Electrochemical Behavior ◽  
Electrode Surface ◽  
Anodic Polarization ◽  
Pure Copper ◽  
Inhibitory Effect ◽  
Open Circuit ◽  
Alkaline Media ◽  
Nacl Solution ◽  
Pure Silver ◽  
Current Densities

Electrochemical behavior of an alloy AgCu50, pure copper, and pure silver, respectively, was investigated by measuring the open circuit potentials using anodic potentiodynamic polarization and potentiostatic method in 0.1 moldm-3 NaOH + 0.02 moldm-3 NaCl solution, without and with adding 2-mercaptobenzothiazole in various concentrations (0.00001 - 0.001 moldm-3). Anodic polarization curves for AgCu50 alloy, showed four current peaks. Potentiostatic curves showed that values of the stationary current densities drop down with the increase of 2-mercaptobenzothiazole concentration in the electrolyte. The electrode surface was analyzed by optical microscopy after the potentiostatic oxidation. Micrographs confirmed that 2-mercaptobenzothiazole has got the inhibitory effect by forming the film of CuMBT and AgMBT which protect the electrode surface from corrosion.

Polarization Studies of Aluminum Alloys In Water at 200 C and 300 C

CORROSION ◽  
1963 ◽  
Vol 19 (4) ◽  
pp. 146t-155t ◽  
Author(s):  
J. H. GREENBLATT ◽  
A. F. McMILLAN
Keyword(s):  
Anodic Polarization ◽  
Cathodic Polarization ◽  
Oxidation Potential ◽  
Electronic Conduction ◽  
Film Resistance ◽  
Applied Current ◽  
Weight Gain Data ◽  
Current Densities ◽  
Polarization Studies ◽  
Impressed Current

Abstract Specimens of commercial 2S aluminum and two special alloys containing iron and nickel were polarized anodically and cathodically at a number of different current densities at 200 C and 300 C. Weight gains were obtained and the potentials relative to the stainless steel autoclave were measured by an interrupter method. The weight gain data indicated that the polarizing current is being carried by electronic conduction. The potential-time curves for anodic polarization indicate differences between 2S aluminum and the alloys in that greater polarization is obtained with the latter. These curves also indicate that the impressed current decreases the film resistance. In all cases the potential reached a plateau value with time and this time was shorter for the alloys. The potential-time curves for cathodic polarization also show plateau values but the rise to a plateau value is in the opposite sense to the applied current. With increasing cathodic polarization the plateau values occur at more negative values of the potential. This latter trend is in the same direction as the applied polarizing current. This apparently is explained in terms of the build-up of the aluminum oxidation potential which acts in a sense opposite to the applied current. Again the time to reach plateau values was shorter for the alloys. Voltage current curves were also obtained on specimens left overnight (approximately 17 hours) at two different anodic polarizing currents. These curves indicated differences between 2S aluminum and the alloys; these differences are discussed in terms of the semi-conducting properties of the oxide film. The observations made on the differences in the properties of the oxide films on the materials examined as revealed by potential and polarization curves are discussed as to their significance in determining corrosion resistance.

Effect of Anodic Surface Treatment on PAN-Based Carbon Fiber and its Relationship to the Fracture Toughness of the Carbon Fiber-Reinforced Polymer Composites

2007 ◽  
Vol 567-568 ◽  
pp. 233-236
Author(s):  
Hamid Sarraf ◽  
Ludmila Škarpová
Keyword(s):  
Fracture Toughness ◽  
Contact Angle ◽  
Carbon Fiber ◽  
Surface Treatment ◽  
Polymer Composites ◽  
Fiber Surface ◽  
Resin Matrix ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Current Densities

The effect of anodic surface treatment on the polyacrylonitrile (PAN)-based carbon fibers surface properties and the mechanical behavior of the resulting carbon fiber-polymer composites has been studied in terms of the contact angle measurements of fibers and the fracture toughness of composites. Results from contact angle measurements revealed that the angle of electrolyte solution largely decreases with increasing current densities of treatments up to 0.4-0.5 A m-2. The results obtained from the evolution of KIC with flexure of the composites as a function of electric current density shown that the KIC of the composite continually increases with increased current densities of the treatments up to 0.5 A m-2, and a maximum strength value is found about 294 MPa cm1/2 at the anodic treatment of 0.5 A m-2. It can be concluded that the anodic surface treatment is largely influenced in the fiber surface nature and the mechanical interfacial properties between the carbon fiber and epoxy resin matrix of the resulting composites, i.e., the fracture toughness. We suggest that good wetting plays an important role in improving the degree of adhesion at interfaces between fibers and matrices of the resulting composites.

scholarly journals Preparation of thick silica coatings on carbon fibers with fine-structured silica nanotubes induced by a self-assembly process

2017 ◽  
Vol 8 ◽  
pp. 1145-1155 ◽  
Author(s):  
Benjamin Baumgärtner ◽  
Hendrik Möller ◽  
Thomas Neumann ◽  
Dirk Volkmer
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
High Surface ◽  
Fiber Surface ◽  
Silica Coating ◽  
High Catalytic Activity ◽  
Covalent Bonds ◽  
Linear Poly ◽  
Carbon Fiber Surface ◽  
Long Chain

A facile method to coat carbon fibers with a silica shell is presented in this work. By immobilizing linear polyamines on the carbon fiber surface, the high catalytic activity of polyamines in the sol–gel-processing of silica precursors is used to deposit a silica coating directly on the fiber’s surface. The surface localization of the catalyst is achieved either by attaching short-chain polyamines (e.g., tetraethylenepentamine) via covalent bonds to the carbon fiber surface or by depositing long-chain polyamines (e.g., linear poly(ethylenimine)) on the carbon fiber by weak non-covalent bonding. The long-chain polyamine self-assembles onto the carbon fiber substrate in the form of nanoscopic crystallites, which serve as a template for the subsequent silica deposition. The silicification at close to neutral pH is spatially restricted to the localized polyamine and consequently to the fiber surface. In case of the linear poly(ethylenimine), silica shells of several micrometers in thickness can be obtained and their morphology is easily controlled by a considerable number of synthesis parameters. A unique feature is the hierarchical biomimetic structure of the silica coating which surrounds the embedded carbon fiber by fibrillar and interconnected silica fine-structures. The high surface area of the nanostructured composite fiber may be exploited for catalytic applications and adsorption purposes.

Evaluating the Electrochemical Properties in the Protection Potential of Material for Use in Al Vessels in Seawater

2006 ◽  
Vol 510-511 ◽  
pp. 158-161 ◽  
Author(s):  
Seong Jong Kim
Keyword(s):  
Current Density ◽  
Anodic Polarization ◽  
High Strength ◽  
Added Value ◽  
Potential Range ◽  
Al Alloy ◽  
Sudden Increase ◽  
Self Healing ◽  
7075 Al Alloy ◽  
Current Densities

FRP (fiber-reinforced polymer) ships used with small boats for fishing pose numerous problems related to both the environment and recycling. From this perspective, aluminum offers an environmentally friendly substitute for FRP that is easy to recycle and imparts a high added value to fishing boats, with a reduction in fuel demands. The current density of 7075 Al alloy increases linearly with an increase in potential during anodic polarization, which implies that no passivation of this alloy occurs. With 1050 and 5456 alloys, passive films form during anodic polarization but are destroyed by the Cl in seawater, only to regrow as a result of the self-healing capacity of aluminum. A shift to more anodic or cathodic conditions in the potential range of –1.5 ~ –0.68 V resulted in a sudden increase in current density. Current densities in the high-strength 7075 Al alloy showed the greatest values. In contrast, the current densities of 5456 alloy, known to have excellent corrosion resistance in seawater, were the lowest in the range of –0.70 ~ –1.3 V, and we conclude that this potential range offers optimal protection.

Study of Transcrystallization in Polymer Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
Benjamin S. Hsiao ◽  
J. H. Eric
Keyword(s):  
Thermal Conductivity ◽  
Free Energy ◽  
Carbon Fiber ◽  
Plasma Treatment ◽  
Polymer Composites ◽  
High Performance ◽  
Interfacial Strength ◽  
Fiber Surface ◽  
Semicrystalline Polymers ◽  
First Case

AbstractTranscrystallization of semicrystalline polymers, such as PEEK, PEKK and PPS, in high performance composites has been investigated. It is found that PPDT aramid fiber and pitch-based carbon fiber induce a transcrystalline interphase in all three polymers, whereas in PAN-based carbon fiber and glass fiber systems, transcrystallization occurs only under specific circumstances. Epitaxy is used to explain the surface-induced transcrystalline interphase in the first case. In the latter case, transcrystallization is probably not due to epitaxy, but may be attributed to the thermal conductivity mismatch. Plasma treatment on the fiber surface showed a negligible effect on inducing transcrystallization, implying that surface-free energy was not important. A microdebonding test was adopted to evaluate the interfacial strength between the fiber and matrix. Our preliminary results did not reveal any effect on the fiber/matrix interfacial strength of transcrystallinity.

Preparation and Property of Epoxy Based Nano-SiO2/TiO2/Polyimide Hybrid Enhanced Sizing

2011 ◽  
Vol 335-336 ◽  
pp. 96-100
Author(s):  
Cun Zhou ◽  
Jian Li Cheng ◽  
Yu Sun
Keyword(s):  
Carbon Fiber ◽  
Sol Gel ◽  
Fiber Surface ◽  
Nano Particles ◽  
Interface Properties ◽  
Particle Size Analyzer ◽  
Complex Technology ◽  
Carbon Fiber Surface ◽  
Interlaminar Shear ◽  
Micro Morphology

Abstract: An epoxy based nano-SiO2/TiO2/polyimide hybrid enhanced sizing for carbon fiber was prepared by modified SiO2/TiO2precursor in PAA collosol with silane couple agent(WD-50) and eligibility surfactant via sol-gel reaction, and both ultrasonic cavitation and multi-complex technology were used during the process. The properties of PAA-SiO2-TiO2hybrid sizing and micro-morphology of carbon fiber surface were analyzed by FTIR, DSC, Particle Size Analyzer and STM. The results indicated that nanoscale SiO2•TiO2particles dispersed in the hybrid sizing film homogeneously, and a layer with nano particles was formed on carbon fiber surface after treated by the hybrid enhanceing sizing. The roughness was increased and interface properties of carbon fiber would be improved. At the same time both tensile strength and the interlaminar shear strength were increased obviously.

Fabrication and Research of Electroless Nickel Plating on Carbon Fiber with Palladium-Free Activation

2010 ◽  
Vol 148-149 ◽  
pp. 410-415
Author(s):  
Xiao Ping Luo ◽  
Ming Gang Zhang ◽  
Chun Xiang Lv
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Fiber Surface ◽  
Electroless Nickel ◽  
Electroless Nickel Plating ◽  
Nickel Plating ◽  
Adhesive Properties ◽  
Nickel Deposition ◽  
X Ray ◽  
Electroless Ni

A new procedure of surface activation without using palladium salt is proposed for electroless nickel plating (Ni-P) on carbon fiber. The optimal formula and technical conditions for palladium-free activated electroless Ni-P were obtained by orthogonal experiments. The effects of nitric acid processing time on the quality of nickel coating was investigated .The effects of varying concentrations of Ni2 + on the rate of weight gain during the Ni2 + complex adsorption process were also analyzed and the kinetic equation of the process was established. The theoretical values calculated by the equation were proven to be consistent with the experimental verification. The material characteristics of the deposited layers were analyzed by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and X-ray diffraction (XRD). The tensile strength of the carbon fibers was analyzed by the Weibull method, and this showed that when the thickness of the Ni-P coating reached 0.150μm, the tensile strength reached a maximum value. The experimental results showed that the nickel deposition on the carbon fiber surface obtained by this method, had the same uniformity, compactness and adhesive properties as the one by conventional electroless Ni-P.

Effects of Stress and Plastic Deformation on the Corrosion of Steel

CORROSION ◽  
1970 ◽  
Vol 26 (5) ◽  
pp. 189-199 ◽  
Author(s):  
W. D. FRANCE
Keyword(s):  
Plastic Deformation ◽  
Electrochemical Techniques ◽  
Chloride Ions ◽  
Localized Corrosion ◽  
Dissolution Behavior ◽  
Potential Range ◽  
Chemical Corrosion ◽  
Effects Of Ph ◽  
Current Densities ◽  
The Stability

Abstract The rate and type of corrosion exhibited by mild steel in the annealed, stressed, and plastically deformed state have been investigated. Precise electrochemical techniques provided potential and polarization data to supplement the results of chemical corrosion tests. Experiments were conducted in 0.6M NH4NO3 solutions in which steel exhibits active-passive dissolution behavior as well as localized corrosion. At active potentials, the anodic polarization curves for annealed and deformed specimens were nearly identical, with only slight increases in current densities for the deformed steel. Results at passive potentials demonstrated that increased plastic deformation can markedly decrease the passive potential range, the stability of passivity, and the ability to passivate. At certain passive potentials, the deformed steel exhibited current densities that were 400 times greater than those for annealed steel. The effects of pH, chloride ions, and crevices on the corrosion of deformed steel were examined in detail. The differences between the dissolution behavior of annealed and deformed steel were most distinctive in the approximate pH range of 3 to 6. This work is relevant to the understanding of the initiation of localized corrosion and to anodic protection.

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