scholarly journals Electrochemical Deposition Treatment (EDT) as a Comprehensive Rehabilitation Method for Corrosion-Induced Deterioration in Concrete with Various Severity Levels

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6287
Author(s):  
Je-Kyoung Kim ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee
Keyword(s):  
Electrochemical Deposition ◽  
Electrochemical Impedance ◽  
Test Phase ◽  
Post Treatment ◽  
Charging Time ◽  
Comprehensive Rehabilitation ◽  
Severity Levels ◽  
Surface Breaking Crack ◽  
Concentration Levels ◽  
Mgcl2 Solution

The primary purposes of this study are to investigate the feasibility of electrochemical deposition treatment (EDT) as a comprehensive rehabilitation method for corrosion-induced deterioration in reinforced concrete with various severity levels, and to propose a guideline for the determination of critical factors to advance EDT. This study includes three experimental phases, each of which simulates the initiation (de-passivation), propagation (high corrosion activity), and acceleration (formation of a surface-breaking crack) periods of corrosion-induced deterioration. After completion of a series of accelerated corrosion tests, damaged concrete samples with different severity levels are rehabilitated by a series of EDT processes using a MgCl2 solution in an electrolyte. The main variables for this experiment are the concentration levels (0, 0.3, 1.0 and 3.0 M) of a MgCl2 solution for test phase 1, charging time (0, 2, and 7 days) in EDT for test phase 2, and configuration of pre- and post-treatment processes in EDT for test phase 3. The rehabilitation performance of EDT is evaluated by analyzing the AC impedance properties of the steel-and-concrete interface using electrochemical impedance spectroscopy (EIS) for the test phases 1 and 2, and microscopic alternation in concrete cracks using optical microscopic image and SEM/EDX. It is demonstrated that EDT is an effective method for preventing and mitigating corrosion-induced deterioration in the initiation and rust propagation periods of corrosion and for repairing (closing and filling) a corrosion-induced surface-breaking crack in the acceleration phase of corrosion. Corrosion-resistant performance of concrete increases as the concentration levels of a MgCl2 solution in an electrolyte increases and as the charging time in EDT increases. In addition, a post-treatment process (applying a NaOH solution) after the electrochemical deposition process significantly improves crack-repairing performance of EDT.

scholarly journals A simple one-step electrochemical deposition of bioinspired nanocomposite for the non-enzymatic detection of dopamine

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vijayaraj Kathiresan ◽  
Dinakaran Thirumalai ◽  
Thenmozhi Rajarathinam ◽  
Miri Yeom ◽  
Jaewon Lee ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Electrochemical Impedance ◽  
High Surface ◽  
Electrochemical Characteristics ◽  
Surface Areas ◽  
Electrochemically Reduced Graphene Oxide ◽  
Sensitivity And Selectivity ◽  
Controlled Deposition ◽  
Enzymatic Detection ◽  
Walled Carbon Nanotubes

AbstractA simple and cost-effective electrochemical synthesis of carbon-based nanomaterials for electrochemical biosensor is of great challenge these days. Our study describes a single-step electrochemical deposition strategy to prepare a nanocomposite of electrochemically reduced graphene oxide (ErGO), multi-walled carbon nanotubes (MWCNTs), and polypyrrole (PPy) in an aqueous solution of pH 7.0 for dopamine (DA) detection. The ErGO/MWCNTs/PPy nanocomposites show enhanced electrochemical performance due to the strong π–π* stacking interactions among ErGO, MWCNTs, and PPy. The efficient interaction of the nanocomposites is confirmed by evaluating its physical and electrochemical characteristics using field-emission scanning electron microscopy, Raman spectroscopy, electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The deposited nanocomposites are highly stable on the substrates and possess high surface areas, which is vital to improve the sensitivity and selectivity for DA detection. The controlled deposition of the ErGO/MWCNTs/PPy nanocomposites can provide enhanced electrochemical detection of DA. The sensor demonstrates a short time response within 2 s and is a highly sensitive approach for DA detection with a dynamic linear range of 25–1000 nM (R2 = 0.999). The detection limit is estimated to be 2.3 nM, and the sensor sensitivity is calculated to be 8.96 μA μM−1 cm−2, with no distinct responses observed for other biological molecules.

scholarly journals Carbon Nanotube Fiber Pretreatments for Electrodeposition of Copper

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Pyry-Mikko Hannula ◽  
Minttu Junnila ◽  
Dawid Janas ◽  
Jari Aromaa ◽  
Olof Forsén ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Carbon Nanotube ◽  
Boric Acid ◽  
Electrochemical Deposition ◽  
Electrochemical Impedance ◽  
Copper Deposition ◽  
High Resistivity ◽  
Active Surface Area ◽  
Carbon Nanotube Fiber ◽  
Watts Bath

There is increasing interest towards developing carbon nanotube-copper (CNT-Cu) composites due to potentially improved properties. Carbon nanotube macroscopic materials typically exhibit high resistivity, low electrochemical reactivity, and the presence of impurities, which impede its use as a substrate for electrochemical deposition of metals. In this research, different CNT fiber pretreatment methods, such as heat treatment, immersion in Watts bath, anodization, and exposure to boric acid (H3BO3), were investigated to improve the electrochemical response for copper deposition. It was shown that these treatments affect the surface activity of CNTs, including electrical resistivity, polarization resistance, and active surface area, which influence the electrodeposition process of copper. Properties of CNT structures and CNT-Cu composites were researched by electrochemical impedance spectroscopy (EIS), galvanostatic copper deposition, scanning electron microscope (SEM), and four-point electrical resistance measurements. Heat treatment, Watts bath, anodization, and boric acid treatments were shown to be effective for modifying the CNT surface reactivity for subsequent electrochemical deposition of copper.

The Effect of Hydrothermal Post Treatments on Corrosion Properties of SnO2 Films in Simulated PEMFC Environments

2012 ◽  
Vol 616-618 ◽  
pp. 1684-1688
Author(s):  
Hong Yun ◽  
Chun Yang Ren ◽  
Yang Cao ◽  
Jun Jie Gao ◽  
Qun Jie Xu
Keyword(s):  
Electrochemical Impedance ◽  
Contact Angles ◽  
Proton Exchange ◽  
Post Treatment ◽  
304 Stainless Steel ◽  
Hydrophobic Property ◽  
Corrosion Properties ◽  
Compact Structure ◽  
Water Contact ◽  
Naoh Solution

SnO2films were supplied on the surface of 304 stainless steel (304SS) by a sol–gel process followed by a hydrothermal post treatment. The measurements of XRD, SEM and water contact angles were carried out to characterize the as-prepared samples. The effect of hydrothermal post treatments in different media such as deionized (DI) water, HF solution and NaOH solution on the corrosion performances of the SnO2films in simulated proton exchange membrane fuel cells (PEMFC) environments was investigated by electrochemical impedance spectroscopy (EIS) and polarization measurements. The results suggested that the SnO2films via the hydrothermal post treatment in 0.3 M NaOH solution showed a highest corrosion resistance and could act as an optimal barrier layer to metallic bipolar plates in simulated PEMFC environments. It could be attributed that the hydrothermal post treatment in NaOH solution was beneficial to improve the compact structure and enhance the hydrophobic property of the SnO2films.

Electrochemical Deposition Mechanism of Polyaniline at High Potential in Organic Electrolyte

2011 ◽  
Vol 284-286 ◽  
pp. 2272-2275 ◽  
Author(s):  
Feng Yi Li ◽  
Wei Wang ◽  
Ben Lin He ◽  
Ming Liang Sun ◽  
Ling Xia Song
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Deposition ◽  
Electrochemical Impedance ◽  
High Potential ◽  
Organic Electrolyte ◽  
Carbon Electrode ◽  
Deposition Mechanism ◽  
Inorganic Electrolyte ◽  
And Diffusion ◽  
Scanning Electron

Polyaniline (PANI) was deposited on the glassy carbon electrode in organic electrolyte. The deposition mechanism and properties of resulted PANI were characterized with Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Electrochemical Impedance Spectroscopy (EIS). The results show that: the polymerization of PANI can carry in a relatively high potential (2.4V), and the electrochemical deposition mechanism of PANI at high potential in organic electrolyte is different from that in inorganic system due to the low conductivity and diffusion coefficient of organic electrolyte. The electro-conductivity of PANI is good in the range of 0.2~0.8V which is wider than that reported in inorganic electrolyte.

n-Type Cu2O/α-Fe2O3 Heterojunctions by Electrochemical Deposition: Tuning of Cu2O Thickness for Maximum Photoelectrochemical Performance

2018 ◽  
Vol 232 (9-11) ◽  
pp. 1551-1566 ◽  
Author(s):  
Soniya Gahlawat ◽  
Nusrat Rashid ◽  
Pravin P. Ingole
Keyword(s):  
Oxide Layer ◽  
Electrochemical Deposition ◽  
Cuprous Oxide ◽  
Electrochemical Impedance ◽  
Base Material ◽  
Morphological Characteristics ◽  
Linear Sweep Voltammetry ◽  
Photoelectrochemical Performance ◽  
Photoelectrochemical Activity ◽  
X Ray

Abstract Here, we report the enhanced photoelectrochemical performance of surface modified hematite thin films with n-type copper oxide nanostructures (Cu2O/Fe2O3) obtained through simple electrochemical deposition method. The thickness and amount of cuprous oxide layer were varied by simply changing the number of electrodeposition cycles (viz. 5, 10, 25, 50 and 100) in order to understand its thermodynamic and kinetic influence on the photoelectrochemical activity of the resultant nano-heterostructures. Structural and morphological characteristics of the obtained Cu2O/Fe2O3 films have been studied by absorption spectroscopy, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis. Electrochemical investigations such as linear sweep voltammetry, Mott–Schottky analysis, and electrochemical impedance spectroscopy suggested the formation of n-type Cu2O layers over the hematite films with varying charge-carrier densities, ranging from 0.56×1019 to 3.94×1019 cm−3, that varies with the number of cycles of electrochemical deposition. Besides, the thickness of deposited cuprous oxide layer is noted to alter the net electrochemical and photo-electrochemical response of the base material. An interesting, peak event was recorded for a particular thickness of the cuprous oxide layer (obtained after 25 cycles of electrochemical deposition) below and above which the efficiency of catalyst was impaired. The heterojunction obtained thus, followed well known Z-scheme and gave appreciable increment in the photocurrent response.

Orthodontic Treatment Need in an Accredited Graduate Orthodontic Center in North America: A Pilot Study

2006 ◽  
Vol 7 (2) ◽  
pp. 87-94 ◽  
Author(s):  
Chukwudi Ochi Onyeaso ◽  
Ellen A. BeGole
Keyword(s):  
Pilot Study ◽  
North America ◽  
Orthodontic Treatment ◽  
Post Treatment ◽  
Treatment Needs ◽  
Duration Of Treatment ◽  
Treatment Need ◽  
Severity Levels ◽  
Pre Treatment ◽  
Age Range

Abstract Aim To assess the objective orthodontic treatment needs of patients treated in an accredited Orthodontic Clinic in North America using a retrospective cross sectional study and the Dental Aesthetic Index (DAI). Methods and Materials One hundred pre- and post-treatment study models were randomly selected from the model storage facility of the clinic. Only the pre-treatment study models were assessed using the DAI. The pre - treatment and post- treatment ages for each case were noted as recorded on the corresponding study models. The range for the pre-treatment age was 10 to 52 years, and from 12 years, 4 months to 54 years for the post-treatment age range. The duration of treatment for each case was calculated by subtracting the pre-treatment age from the post-treatment age (range of treatment duration, 9 to 125 months). Descriptive statistics as well as chi-square statistics were employed to analyze the data. Results Fifteen cases had normal or minor malocclusions with no treatment or slight need for treatment. Definite malocclusions with treatment highly desirable accounted for 22 cases and severe malocclusion with treatment highly desirable was found in 16 cases. Forty-seven cases had handicapping malocclusion with treatment considered mandatory. While a statistically significant association (p<0.05) was found between duration of treatment and severity levels of malocclusion (DAI scores), the association between pre-treatment age and DAI scores was not significant (p > 0.05). Conclusions Eighty-five percent of the study sample needed orthodontic treatment with different malocclusion severity levels, while 47% of the cases qualified for publicly subsidized treatment due to handicapping malocclusions. The association between duration of treatment and DAI score groups (malocclusion severity levels) was found statistically significant. It could be helpful for more clinic-based (demand populations) studies on treatment needs be undertaken across the globe using the DAI, at least for the purposes of comparison. Citation Onyeaso CO, BeGole EA. Orthodontic Treatment Need in an Accredited Graduate Orthodontic Center in North America: A Pilot Study. J Contemp Dent Pract 2006 May;(7)2:087-094.

A Highly Sensitive Electrochemical Impedimetric Nanobiosensor for Dust Mite Antigen Der p2 Detection

2011 ◽  
Author(s):  
I-Jiuan Bau ◽  
Gou-Jen Wang
Keyword(s):  
Gold Nanoparticles ◽  
Electrochemical Deposition ◽  
Barrier Layer ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
Sensing Element ◽  
Self Assembled Monolayer ◽  
Highly Sensitive ◽  
Der P2 ◽  
Dust Mite

The group 2 allergen, Der p2, has been reported to activate innate toll-like receptors (TLRs) on respiratory epithelial cells and thus aggravate respiratory diseases. In this study, a high sensitive nanobiosensor based on a 3D sensing element that has uniformly deposited gold nanoparticles for the detection of the dust mite antigen Der p2 is proposed. The barrier layer of an anodic aluminum oxide (AAO) film is used as the template in this highly sensitive nanobiosensor fabricated with a reducing agent and stabilizer-free method. Electrochemical deposition is utilized to synthesize uniformly distributed gold nanoparticles on the surface of the barrier layer. The size and the distribution density of the nanoparticles can be well controlled by the potential applied during electrochemical deposition. Following this procedure, monoclonal antibodies were immobilized against the dust mite antigen Der p2 by the gold nanoparticles through the 11-MUA (11-mercaptoundecanoic acid), EDC (1-Ethyl-3-(3-dimethyl-aminopropyl)-carbodiimide)/NHS (N-hydroxysuccinimide) self-assembled monolayer approach. The proposed nanobiosensor was successfully used to examine the Der p2 down to a concentration of 1pg/mL through the electrochemical impedance spectroscopy analysis. The high sensitivity of the proposed 3D nanobiosensor can be attributed to the high intensity and uniformity of the Au nanoparticles on the sensor. The proposed nanobiosensor would be useful for the fast detection of rare molecules in a solution.

scholarly journals A template/electrochemical deposition method for fabricating silver nanorod arrays based on porous anodic alumina

2017 ◽  
Vol 7 ◽  
pp. 184798041771754 ◽  
Author(s):  
Yafang Li ◽  
Jie Xu ◽  
Hao Liu ◽  
Jinzhong Song ◽  
Yashuang Li ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Barrier Layer ◽  
Electrochemical Impedance ◽  
Average Diameter ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Nanorod Arrays ◽  
Deposition Method ◽  
Electrochemical Deposition Method ◽  
Anodic Alumina Templates

A template/electrochemical deposition method for fabricating silver nanorod arrays based on porous anodic alumina was presented. The barrier layer of porous anodic alumina templates was thinned by step-by-step voltage decrement method. Subsequently, silver ions were reduced into the channels of porous anodic alumina templates by electrochemical deposition method. Electrochemical impedance spectroscopy was utilized for analyzing the thickness of barrier layer of porous anodic alumina templates; the elementary composition and the size of silver nanorod arrays were characterized by X-ray diffraction and field-emission scanning electron microscope, respectively. Experimental results showed that the thickness of barrier layer of porous anodic alumina was suitable for alternating current electrochemical deposition, when anodizing potential was decreased to 70 V and widening time of porous anodic alumina in H3PO4 solution is 80 min. And the silver particles could be deposited into the channels of porous anodic alumina templates at 11 V, 13 V, and 15 V. Different sizes of silver nanorod arrays were obtained by controlling the deposition time. The average diameter of silver nanorod is in the range from 346 nm to 351 nm which is almost consistent with the pore diameter of porous anodic alumina templates (367 nm). The uniform silver nanorod arrays have a considerable potential in the flexible and wearable electronic devices, optics, solar cell, the catalytical electrode, and so on.

Influence of Silane Films in the Zinc Coating Post-Treatment

2010 ◽  
Vol 660-661 ◽  
pp. 215-220
Author(s):  
Marlla Vallerius da Costa ◽  
Cláudia Trindade Oliveira ◽  
Jean Pierre Bonino ◽  
Tiago Lemos Menezes ◽  
Célia Fraga Malfatti ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Protective Efficacy ◽  
Sol Gel ◽  
Zinc Coating ◽  
Polymeric Materials ◽  
High Strength ◽  
Dip Coating ◽  
Post Treatment ◽  
Pure Zinc ◽  
Homogeneous Surface

The sol-gel process based on silanes precursors appeared in recent years as a strong alternative for post-treatment to provide an optimization of the protective efficacy of zinc. Moreover, this process has been used to replace chemical chromating conversion based on hexavalent chromium. The silane films are hybrid compounds that provide characteristics of both polymeric materials, such as flexibility and functional compatibility, and ceramic materials, such as high strength and durability. The present work aimed to evaluate the influence of silane films obtained by dip-coating, on the characteristics of electrodeposited zinc coatings. The xerogel films showed a homogeneous surface and a better performance on the corrosion resistance than zinc coating without post-treatment, what can be confirmed by the electrochemical impedance results. These tests showed that application of the silane film promotes the occurrence of one more time constant compared to pure zinc system, hindering the corrosion process.

Evaluation of a Comprehensive Rehabilitation Program for Post-Treatment Patients With Cancer

2011 ◽  
Vol 38 (6) ◽  
pp. E418-E424 ◽  
Author(s):  
Sophie Hanssens ◽  
Rik Luyten ◽  
Christiaan Watthy ◽  
Christel Fontaine ◽  
Lore Decoster ◽  
...  
Keyword(s):  
Rehabilitation Program ◽  
Post Treatment ◽  
Patients With Cancer ◽  
Comprehensive Rehabilitation
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