scholarly journals Electrochemical Response of Clay/Polyelectrolyte Composite Barrier Coatings

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1173
Author(s):  
Sumin Kim ◽  
Clare Chisu Byeon ◽  
Sung Yeol Kim
Keyword(s):  
Mass Transport ◽  
Indigo Carmine ◽  
Copper Substrate ◽  
Layer By Layer ◽  
Potential Cycling ◽  
Peak Current ◽  
Redox Peak ◽  
Coated Electrode ◽  
Redox Peak Current ◽  
Current Value

Composite materials made of polymer and clay are effective at blocking mass transport. In this study, the blocking efficacy of layer-by-layer (LbL) coatings of exfoliated montmorillonite (MMT) and polyethylenimine (PEI) was studied using cyclic voltammetry and a redox couple, indigo carmine (IC). The pH of the MMT solution was varied from 4 to 10 to prepare LbL coatings of different surface roughness on metal substrates. It was found that the coated electrode had a lower redox peak current value than without the coating, demonstrating the reduction of the mass transport of IC to the metal surface. The peak values decreased with decreasing the coating’s roughness and increasing the number of layers, indicating that the blocking capability can be controlled by changing the deposition conditions. Smooth LbL coatings deposited with MMT at pH 4 showed the highest blocking efficacy up to 97.5%. The IC adsorbed at the interface between the coating and the metal substrate was found to cause the peak current measured for the coated electrode. It was also confirmed that the same coating on the copper substrate reduced the corrosion of the copper during the electrochemical potential cycling.

Fabrication of layer-by-layer graphene oxide thin film on copper substrate by electrophoretic deposition

2020 ◽  
Vol 59 (12) ◽  
pp. 125001
Author(s):  
Nan Ye ◽  
Satoka Ohnishi ◽  
Mitsuhiro Okada ◽  
Kazuto Hatakeyama ◽  
Kazuhiko Seki ◽  
...  
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Electrophoretic Deposition ◽  
Copper Substrate ◽  
Oxide Thin Film ◽  
Layer By Layer ◽  
Layer Graphene

scholarly journals Surface Modification Effect and Electrochemical Performance of LiOH-High Surface Activated Carbon as a Cathode Material in EDLC

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2187
Author(s):  
Zambaga Otgonbayar ◽  
Sunhye Yang ◽  
Ick-Jun Kim ◽  
Won-Chun Oh
Keyword(s):  
Activated Carbon ◽  
Cathode Material ◽  
Electrochemical Properties ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Oxidizing Agent ◽  
Peak Current ◽  
X Ray ◽  
Current Value

This study aimed to improve the performance of the activated carbon-based cathode by increasing the Li content and to analyze the effect of the combination of carbon and oxidizing agent. The crystal structure and chemical structure phase of Li-high surface area activated carbon material (Li-HSAC) was analyzed by X-ray diffraction (XRD) and Raman spectroscopy, the surface state and quantitative element by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and the surface properties with pore-size distribution by Brunauer–Emmett–Teller (BET), Barrett–Joyner–Halenda (BJH) and t-plot methods. The specific surface area of the Li-YP80F is 1063.2 m2/g, micropore volume value is 0.511 cm3/g and mesopore volume is 0.143 cm3/g, and these all values are higher than other LiOH-treated carbon. The surface functional group was analyzed by a Boehm titration, and the higher number of acidic groups compared to the target facilitated the improved electrolyte permeability, reduced the interface resistance and increased the electrochemical properties of the cathode. The oxidizing agent of LiOH treated high surface area of activated carbon was used for the cathode material for EDLC (electric double layer capacitor) to determine its electrochemical properties and the as-prepared electrode retained excellent performance after 10 cycles and 100 cycles. The anodic and cathodic peak current value and peak segregation of Li-YP80F were better than those of the other two samples, due to the micropore-size and physical properties of the sample. The oxidation peak current value appeared at 0.0055 mA/cm2 current density and the reduction peak value at –0.0014 mA/cm2, when the Li-YP80F sample used to the Cu-foil surface. The redox peaks appeared at 0.0025 mA/cm2 and –0.0009 mA/cm2, in the case of using a Nickel foil, after 10 cycling test. The electrochemical stability of cathode materials was tested by 100 recycling tests. After 100 recycling tests, peak current drop decreased the peak profile became stable. The LiOH-treated high surface area of activated carbon had synergistically upgraded electrochemical activity and superior cycling stability that were demonstrated in EDLC.

Nucleate Boiling of Dielectric Liquids on Hydrophobic and Hydrophilic Surfaces

2015 ◽  
Author(s):  
Huseyin Bostanci ◽  
Nihal E. Joshua
Keyword(s):  
Heat Transfer ◽  
Performance Enhancement ◽  
Copper Substrate ◽  
Nucleate Boiling ◽  
High Heat ◽  
Copper Surface ◽  
Working Fluid ◽  
High Heat Flux ◽  
Layer By Layer ◽  
Hydrophilic Surfaces

An experimental study was conducted to investigate the effect of hydrophobic, hydrophilic and mixed hydrophobic/hydrophilic surfaces in nucleate boiling heat transfer. A dielectric liquid, HFE-7100, was used as the working fluid in the saturated boiling tests. A total of 12 test samples were used in this study, featuring four types of boiling surfaces with a common copper substrate; (1) plain, smooth copper surface (as reference), (2) hydrophobic patterned or fully-covered surface, (3) hydrophilic patterned or fully-covered surface, and (4) mixed hydrophobic/ hydrophilic patterned surface. All test samples were prepared on 10 mm × 10 mm × 2 mm copper substrates with matching size thick film resistors attached onto the opposite side, to generate heat and simulate high heat flux electronic devices. The fabrication of hydrophobic surfaces involved common photolithography techniques to apply 100 μm thick Teflon layer. Hydrophilic surfaces were prepared by depositing a TiO2 layer through a two-step process involving layer by layer self-assembly (L-B-L) and liquid phase deposition (L-P-D) techniques. Test samples with the mixed hydrophobic/hydrophilic surfaces were obtained by first applying Teflon hydrophobic patterns, and then by covering the remaining substrate area with hydrophilic coating. The effect of pattern and pitch size was investigated by varying the circular pattern dimensions between 40, 100 and 250 μm and corresponding pitch dimensions between 80, 200 and 500 μm. The results indicated that hydrophobic and hydrophilic surfaces have distinct benefits, and mixed hydrophobic/hydrophilic surfaces offer an optimum performance enhancement, providing: (a) early transition to boiling regime with no temperature overshoot at boiling incipience, (b) up to 10.6 kW/m2°C HTC (representing 82% increase), and (c) up to 28 W/cm2 CHF level (representing 47% increase). The studied enhanced surfaces therefore demonstrated a practical surface modification method for heat transfer enhancement in immersion cooling applications.

Effect of Propanetriol on the Electrochemical Behavior of Nano Fumed Silica Gel

2011 ◽  
Vol 110-116 ◽  
pp. 514-518
Author(s):  
Cheng Fang Sun ◽  
Fa Liang Cheng ◽  
Mei Qiong Chen ◽  
Min Zhang ◽  
Zhi Quan Cai
Keyword(s):  
Electrochemical Properties ◽  
Silica Gel ◽  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Peak Current Density ◽  
Gel Properties ◽  
Redox Peak ◽  
Transmission Electron ◽  
Lead Electrode ◽  
Redox Peak Current

The effect of propanetriol on the electrochemical properties of nanofumed silica gel of Valve-regulated lead-acid (VRLA) batteries have been investigated by means of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), transmission electron microscope (TEM) and linear sweep voltammetry (LSV). The results show that with the adding of propanetriol the redox peak current density of the lead electrode greatly increases and the reaction resistance reduces obviously. Additionally, the oxygen reactions take place less easily in the gels containing propanetriol. The content of the additive propanetriol also relates with the gel properties. It is proved that the electrochemical properties of gel contained excessive propanetriol (4wt. %) are not as good as that contain 1wt.%~3wt.%.

Preparation and Photoelectronic Properties of Zinc Oxide/Perovskite Nanocomposites/Polypyrrole

2015 ◽  
Vol 1089 ◽  
pp. 24-27
Author(s):  
Lei Qin ◽  
Sheng Ling Lin ◽  
Xiao Yun Ma
Keyword(s):  
Zinc Oxide ◽  
Combustion Method ◽  
Oxide Content ◽  
Redox Peak ◽  
Reversible Redox ◽  
Redox Peak Current ◽  
Oxide Perovskite ◽  
Glycine Nitrate Combustion ◽  
Different Content

La0.3Ca0.7Fe0.7Ni0.3O3 perovskite-type composite was prepared by glycine-nitrate combustion method , Zinc Oxide was prepared by liquid crystal precipitation, then we synthesized ZnO/La0.3Ca0.7Fe0.7Ni0.3O3/Ppy nanocomposites with different content of Ppy in situ method. XRD,SEM,UV-vis were used to characterized the crystal structure and morphology of the nanocomposites and their photocatalytic activity. Cyclic voltammetry of the composites were conducted in 1mol/L KCl solutions to discuss their electrochemical properties.According to the electrochemical properties, we found that with the increase of the zinc oxide content,the redox peak current of the composites becomes larger, also their reversible redox properties was improved.

scholarly journals Controlled Layer-By-Layer Deposition of Carbon Nanotubes on Electrodes for Microbial Fuel Cells

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 363 ◽  
Author(s):  
Wenguo Wu ◽  
Hao Niu ◽  
Dayun Yang ◽  
Shi-Bin Wang ◽  
Jiefu Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cells ◽  
Modified Electrode ◽  
Current Density ◽  
Indium Tin Oxide ◽  
Microbial Fuel Cells ◽  
Electrochemical Impedance ◽  
Layer By Layer ◽  
Peak Current ◽  
Ito Electrode

Carbon nanotubes (CNTs) and polyelectrolyte poly(allylamine hydrochloride) (PAH) composite modified indium tin oxide (ITO) electrodes, by a layer-by-layer (LBL) self-assembly technique, was evaluated as an anode for microbial fuel cells (MFCs). The bioelectrochemistry of Shewanella loihica PV-4 in an electrochemical cell and the electricity generation performance of MFCs with multilayer (CNTs/PAH)n-deposited ITO electrodes as an anode were investigated. Experimental results showed that the current density generated on the multilayer modified electrode increased initially and then decreased as the deposition of the number of layers (n = 12) increased. Chronoamperometric results showed that the highest peak current density of 34.85 ± 2.80 mA/m2 was generated on the multilayer (CNTs/PAH)9-deposited ITO electrode, of which the redox peak current of cyclic voltammetry was also significantly enhanced. Electrochemical impedance spectroscopy analyses showed a well-formed nanostructure porous film on the surface of the multilayer modified electrode. Compared with the plain ITO electrode, the multilayered (CNTs/PAH)9 anodic modification improved the power density of the dual-compartment MFC by 29%, due to the appropriate proportion of CNTs and PAH, as well as the porous nanostructure on the electrodes.

A Novel Conducting Polymer with O-S-S-O Bonds for Positive Material:Poly(2,2′-Diaminobenzyloxydisulfide)

1999 ◽  
Vol 575 ◽  
Author(s):  
Y. Z. Su ◽  
W. S. Ma ◽  
K. C. Gong
Keyword(s):  
Conducting Polymer ◽  
Electrochemical Behaviour ◽  
High Energy ◽  
Cyclic Voltammograms ◽  
Storage Material ◽  
New Class ◽  
Redox Peak ◽  
Redox Peak Current ◽  
Ft Ir ◽  
Energy Storage Material

ABSTRACTOrganic disulfide compounds has been proposed as a new class of high-energy storage material. Poly(2,2'-diaminobenzyloxydisulfide), a novel conducting polymer having O-S-S-O bond joined two moieties of anilines, is synthesized both chemically and electrochemically as a new positive storage material. It exhibits conductivity in the region of 10-3 S cm-1 by the fourprobe method and the O-S-S-0 bonds in it are confirmed by Fourie Transform Raman Spectroscopy(FT-RS) and Fourie Transform Infrared Spectroscopy(FT-IR). The poly(2,2'- diaminobenzyloxydisulfide) films are formed by electropolymerization from a AN/THF solution containing 0. IM LiClO4, 0. IM HCl and 0.05 M 2,2'-diaminobenzyloxydisulfide monomer on Pt electrode under continuous cycling between -0.30V and 1.20V vs Ag/AgCl(sat. KCI) at scanning rate 50mv s-1. The cyclic voltammetry shows its electrochemical behaviour is similar to polyaniline. The redox peak current of the cyclic voltammograms increase with increasing of the cyclic numbers.

Electrochemical detection of non-labeling DNA using electronic array

2002 ◽  
Vol 735 ◽  
Author(s):  
H. Y. Lee ◽  
J. W. Park ◽  
Y. S. Choi ◽  
T. Kannno ◽  
Hiro. Tanaka ◽  
...  
Keyword(s):  
Electron Transport ◽  
Nucleic Acids ◽  
Electrochemical Detection ◽  
Dna Hybridization ◽  
Detection System ◽  
Good Reproducibility ◽  
Redox Peak ◽  
Target Dna ◽  
Redox Peak Current ◽  
Hybridization Detection

Our system is the electrochemical approaches include the detection of hybridization from nonlabeling nucleic acids to protein-bound nucleic acids using soluble mediators with K4Fe(CN)6 solutions. In order to generate bio-functional surfaces, the streptavidin(SAv)-biotin system is used. A 50 % change of redox peak current after hybridization measured with 50 μM concentration of target DNA. We suggest that this result comes from the efficient electron transport through the SAv-biotin interaction. Our electrochemical detection system showed good reproducibility on a chip with non-labeling DNA hybridization detection.

Electrochemical detection of non-labeling DNA using electronic array

2002 ◽  
Vol 761 ◽  
Author(s):  
H. Y. Lee ◽  
J. W. Park ◽  
Y. S. Choi ◽  
T. Kannno ◽  
Hiro. Tanaka ◽  
...  
Keyword(s):  
Electron Transport ◽  
Nucleic Acids ◽  
Electrochemical Detection ◽  
Dna Hybridization ◽  
Detection System ◽  
Good Reproducibility ◽  
Redox Peak ◽  
Target Dna ◽  
Redox Peak Current ◽  
Hybridization Detection

Our system is the electrochemical approaches include the detection of hybridization from nonlabeling nucleic acids to protein-bound nucleic acids using soluble mediators with K4Fe(CN)6 solutions. In order to generate bio-functional surfaces, the streptavidin(SAv)-biotin system is used. A 50 % change of redox peak current after hybridization measured with 50 ?M concentration of target DNA. We suggest that this result comes from the efficient electron transport through the SAv-biotin interaction. Our electrochemical detection system showed good reproducibility on a chip with non-labeling DNA hybridization detection.

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