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Two new random donor-acceptor (D-A) copolymers, signed as P1 and P2, were designed and synthesized. Electrochemical and spectroelectrochemical measurements were performed to investigate absorption, energy levels, electronic and optical band gaps for comparison. The polymers were used as donor polymers in the active layer to fabricate non-fullerene, bulk heterojunction (BHJ) organic photovoltaics (OPVs). Investigations were carried out through the conventional BHJ structure; ITO/PEDOT: PSS/Active Layer/LiF/Al, where active layer consists of 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophene (ITIC) as the acceptor and thienopyrroledione containing donors. The device based on P1:ITIC(1:1) blend with a thickness of 161 nm gave the best performance with a power conversion efficiency (PCE) of 7.94%, an open-circuit voltage (V-OC) of 0.86 V, a short-current density (J(SC)) of 18.45 mA cm(-2) and a fill factor (FF) of 50.12%. The highest PCE obtained from P2 based organic solar cell is 1.96%. P2 exhibited low solubility attributed to the lack of alkyl groups enhancing polymer solubility, electronic properties, and photovoltaic performances. The research outputs exhibit that introduction of alkyl chains on the polymer backbone can enhance device performance. (C) 2021 Elsevier Ltd. All rights reserved.

In this paper, an electrochemical method was proposed to recycle nanoarchitectonics of graphene oxide (GO) from carbon fiber reinforced polymer (CFRP). In the recycling process, NaCl solution with varied concentrations (3% and 10%) and tap water were used as electrolyte, while the impressed current density varied from 2.67 A/m2 to 20.63 A/m2. The results indicated that in NaCl electrolyte, the obtained nanoarchitectonics of GO contained a large amount of nano-carbon onions (NCO) produced by etching CFRP, while high purity GO was produced when tap water was used as electrolyte. The higher current density improved the production efficiency and resulted in a finer GO particle size. The proposed recycling method of GO is economical and simple to operate. It also provides an alternate approach to handle discarded CFRP.

Generally, our ecosystem is continuously contaminated as a result of anthropogenic activities that form the basis of our comfort in our routine life. Thus, most scientists are engaged in the development of new technologies that can be used in environmental remediation. Herein, highly calcined binary metal oxide (Er2O3@NiO) semiconductor nanocomposite (NC) was synthesized using a classical wet chemical process with the intention to both detect and degrade the toxic chemicals in an aqueous medium using a novel electrochemical current–potential (I–V) approach for the first time. Optical, morphological, and structural properties of the newly synthesized semiconductor NC were also studied in detail using FT-IR, UV/Vis., FESEM-EDS, XPS, BET, EIS, and XRD techniques. Then, a modified glassy carbon electrode (GCE) based on the newly synthesized semiconductor nanocomposite (Er2O3@NiO-NC/Nafion/GCE) as a selective electrochemical sensor was fabricated with the help of 5% ethanolic-Nafion as the conducting polymer binder in order to both detect and electro-hydrolyze toxic chemicals in an aqueous medium. Comparative study showed that this newly developed Er2O3@NiO-NC/Nafion/GCE was found to be very selective against m-tolyl hydrazine (m-Tolyl HDZN) and to have good affinity in the presence of other interfering toxic chemicals. Analytical parameters were also studied in this approach to optimize the newly designed Er2O3@NiO-NC/Nafion/GCE as an efficient and selective m-Tolyl HDZN sensor. Its limit of detection (LOD) at an SNR of 3 was calculated as 0.066 pM over the linear dynamic range (LDR) of our target analyte concentration (0.1 pM–0.1 mM). The limit of quantification (LOQ) and sensitivity were also calculated as 0.22 pM and 14.50 µAµM−1cm−2, respectively. m-Tolyl HDZN is among the toxic chemicals in our ecosystem that have lethal effects in living beings. Therefore, this newly designed electrochemical sensor based on semiconductor nanostructure material offers, for the first time, a cost-effective technique, in addition to long-term stability, that can be used as an alternative for efficiently probing other toxic chemicals in real samples.

Noble metallic nanocrystals are used in a wide variety of applications, such as catalysis, batteries, and bio- and chemical sensors. Most of the previous studies focus on the preparation of thermodynamically stable nanocrystals enclosed by low-index facets and discuss their corresponding catalytic properties. Recently, researchers have found that the nanocrystals with high-index facets (HIFs) are of more interest for electrocatalysis. Herein, we review recent key progress in the synthesis of noble metallic nanoparticles enclosed with HIFs and their facet-dependent electrocatalytic behaviors. First, we introduce the concept of HIFs, and establish the correlation between their surface structure and catalytic activity. Then, we discuss various synthetic approaches for controlling the shapes and composition of the nanocrystals enclosed by HIFs. Afterwards, we showcase the enhanced electrocatalytic performance realized by HIF-based nanostructures. Finally, we provide guidance on how to improve the electrocatalysis by engineering HIFs on noble metallic nanocrystals.

Conjugated polyelectrolyte/MWCNT/poly(pyrrole) (CPE-K/MWCNT/PPY) composites have been prepared by a simple solution mixing technique. Synthesis of PPY/CPE/MWCNT composites was characterized by scanning electron microscopy and thermogravimetric analysis. These nanocomposites of CPE-K/MWCNT/PPY were deposited onto a glassy carbon electrode (GCE) in order to fabricate a reliable Mg2+ cationic sensor. A plot called the calibration curve is produced from the current as a function of concentration of Mg2+ ion. This plot was found to be linear in the range 0.1 nM to 0.01 mM, which is defined as the linear dynamic range. According to the surface area of the GCE (0.0316 cm2) and the slope of the calibration curve, a high sensitivity (19.4968 µA µM–1 cm–2) of the Mg2+ ion sensor was calculated. A significant lower limit of detection (97.71 ± 4.89 pM) was obtained in association with a signal to noise ratio of 3. Sensor parameters such as reproducibility, long-time stability, and short response time were measured and found to be quite satisfactory. This new approach to Mg2+ detection with high sensitivity is suggested for application as a novel multifunctional sensing system. Besides, it was found to be very effective to analyze real environmental samples.

This study reports the development of a fast and facile route for the synthesis of novel TiO2-CeO2 nanocomposite film using sol-gel spin coating method with the mixture of commercial CeO2, titanium-iso-propoxide (TTIP) and aqueous ammonia. Solutions of TTIP in ethanol were mixed with CeO2 nanoparticles to form a mixed sol-gel. The sol containing TiO2-CeO2 was coated over the glass substrate and the resulting nanocomposite thin film were characterized in terms of phase and surface morphology by XRD, TEM, SEM and FT-IR. Conventional methods of the synthesis of CeO2–TiO2 nanocomposite require a long time, and TiO2 is rarely found as a coated material. In contrast, the sol-gel spin coating method was able to synthesize CeO2–TiO2 sol within a very short time. The particle size of the TiO2–CeO2 nano-composite film was found to be 23 nm. The Uric acid biosensor was fabricated by immobilizing mixed enzyme [urease (Urs) and glutamate dehydrogenase (GLDH)] on this nano-composite film showed a response time of 10 s, sensitivity as 0.9016 µAcm−2 mM−1 and detection limit of 0.165 mM. The value of Michaelis–Menten constant (Km) estimated using Line weaver–Burke plot as 4.8 mM which indicates the high affinity of uricase towards its analyte (uric acid). The enhanced sensitivity and linear range of the nanobiocomposite film obtained by cyclic voltammetry measurements suggested that the mixed enzyme and TiO2-CeO2 composite material has novel characteristics for uric acid determination in the human blood for the application of arthritis diseases.

Herein, dendrimer-modified montmorillonite (Mt)-decorated poly-Ɛ-caprolactone (PCL) and chitosan (CHIT)-based nanofibers were prepared. Mt was modified with a poly(amidoamine) generation 1 (PAMAMG1) dendrimer, and the obtained PAMAMG1–Mt was incorporated into the PCL–CHIT nanofiber’s structure. The PCL–CHIT/PAMAMG1–Mt nanofibers were conjugated with glutamate oxidase (GluOx) to design a bio-based detection system for monosodium glutamate (MSG). PAMAMG1–Mt was added to the PCL–CHIT backbone to provide a multipoint binding side to immobilize GluOx via covalent bonds. After the characterization of PCL–CHIT/PAMAMG1–Mt/GluOx, it was calibrated for MSG. The linear ranges were determined from 0.025 to 0.25 mM MSG using PCL–CHIT/Mt/GluOx and from 0.0025 to 0.175 mM MSG using PCL–CHIT/PAMAMG1–Mt/GluOx (with a detection limit of 7.019 µM for PCL–CHIT/Mt/GluOx and 1.045 µM for PCL–CHIT/PAMAMG1–Mt/GluOx). Finally, PCL–CHIT/PAMAMG1–Mt/GluOx was applied to analyze MSG content in tomato soup without interfering with the sample matrix, giving a recovery percentage of 103.125%. Hence, the nanofiber modification with dendrimer-intercalated Mt and GluOx conjugation onto the formed nanocomposite structures was performed, and the PCL–CHIT/PAMAMG1–Mt/GluOx system was successfully developed for MSG detection.

Herein, the detection of aspartic acid by doped Co3O4-ZnO nanorod materials was proposed using differential pulse voltammetry. The nano-composite metal oxide was synthesized by the wet precipitation method in basic media. Aspartic acid is a non-essential amino acid naturally synthesized in the body with lot of health significance, including as a biomarker for several health deficiencies. The synthesized composite Co3O4-ZnO nanorod was well-investigated by using FESEM, XRD, XPS, FTIR, UV/vis., EIS, and CV. The synthesized composite exhibited a low limit of detection (0.03 µM, high sensitivity (0.0014 µA µM−1 cm−2) and wide linear range (0.05–50 µM) for aspartic acid. The substrate, the Co3O4-ZnO nanorod, enhanced the electro-catalytic oxidation of aspartic acid as a result of its catalytic and conductivity properties. The developed sensor based on Co3O4-ZnO has a repeatable, reproducible and stable current response for aspartic acid. Additionally, other electroactive compounds did not interfere with the sensor’s current response. The suitability of the developed sensor for real sample analysis was also established. Therefore, this study proposed the potential use of Co3O4-ZnO nanorod material in healthcare management for the maintenance of human well-being.

Diabetes remains a great threat to human beings’ health and its world prevalence is projected to reach 9.9% by 2045. At present, the detection methods used are often invasive, cumbersome and time-consuming, thus increasing the burden on patients. In this paper, we propose a novel noninvasive and low-cost biosensor capable of detecting glucose in human sweat using enzyme-based electrodes for point-of-care uses. Specifically, an electrochemical method is applied for detection and the electrodes are covered with multilayered films including ferrocene-polyaniline (F-P), multi-walled carbon nanotubes (MWCNTs) and glucose oxidase (GOx) on Cu substrates (GOx/MWCNTs/F-P/Cu). The coated layers enhance the immobilization of GOx, increase the conductivity of the anode and improve the electrochemical properties of the electrode. Compared with the Cu electrode and the F-P/Cu electrode, a maximum peak current is obtained when the MWCNTs/F-P/Cu electrode is applied. We also study its current response by cyclic voltammetry (CV) at different concentrations (0–2.0 mM) of glucose solution. The best current response is obtained at 0.25 V using chronoamperometry. The effective working lifetime of an electrode is up to 8 days. Finally, to demonstrate the capability of the electrode, a portable, miniaturized and integrated detection device based on the GOx/MWCNTs/F-P/Cu electrode is developed. The results exhibit a short response time of 5 s and a correlation coefficient R2 of 0.9847 between the response current of sweat with blood glucose concentration. The LOD is of 0.081 mM and the reproducibility achieved in terms of RSD is 3.55%. The sweat glucose sensor is noninvasive and point-of-care, which shows great development potential in the health examination and monitoring field.

Herein, novel Co3O4·CdO·ZnO-based tri-metallic oxide nanoparticles (CCZ) were synthesized by a simple solution method in basic phase. We have used Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscope (FESEM), Dynamic Light Scattering (DLS), Tunneling Electron Microscopy (TEM), and Energy-Dispersive Spectroscopy (EDS) techniques to characterize the CCZ nanoparticles. XRD, TEM, DLS, and FESEM investigations have confirmed the tri-metallic nanoparticles’ structure, while XPS and EDS analyses have shown the elemental compositions of the CCZ nanoparticles. Later, a Au/μ-Chip was modified with the CCZ nanoparticles using a conducting binder, PEDOT: PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) in a sol-gel system, and dried completely in air. Then, the CCZ/Au/μ-Chip sensor was used to detect methanol (MeOH) in phosphate buffer solution (PBS). Outstanding sensing performance was achieved for the CCZ/Au/μ-Chip sensor, such as excellent sensitivity (1.3842 µAµM−1cm−2), a wide linear dynamic range of 1.0 nM–2.0 mM (R2 = 0.9992), an ultra-low detection limit (32.8 ± 0.1 pM at S/N = 3), a fast response time (~11 s), and excellent reproducibility and repeatability. This CCZ/Au/μ-Chip sensor was further applied with appropriate quantification results in real environmental sample analyses.

An electrochemical sensor based on a cobalt oxide nanorod (Co3O4NR) modified glassy carbon electrode (GCE) (Co3O4NR-GCE) was prepared for simultaneous and selective determination of hydroquinone (HQ) and catechol (CT). Surface morphology and crystallinity of Co3O4NR were investigated employing field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis. The structure (16 nm) of the Co3O4 nanorod was observed in the FESEM image. A sharp peak pattern in the XRD survey revealed the following crystal planes in Co3O4NR material: (111), (220), (311), (222), (400), (422), (511), and (440). Electrochemical characterization of modified Co3O4NR-GCE was carried out performing cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Selective and simultaneous detection of HQ and CT was carried out by performing CV and differential pulse voltammetry (DPV) analysis. In both studies, modified Co3O4NR-GCE showed well defined oxidation and reduction peaks for HQ and CT with enhanced peak current, and the oxidation peaks for HQ and CT were observed at 0.152 V and 0.254 V, respectively, in the CV analysis. Scan rate and pH variation analysis were performed to evaluate different kinetic parameters, including charge transfer coefficient (α = 0.56 for HQ and 0.66 for CT), heterogeneous charge transfer rate constant (ks = 56 for HQ and 72 for CT), and the number of electrons involved in HQ and CT oxidation. Quantitative analysis of HQ and CT was studied by observing the current response of DPV analysis with respect to concentration variation. Here, the detection limit was calculated as 0.2 µM for HQ with a linear concentration range of 5–200 µM, and 0.4 µM for CT with a linear concentration range of 5–150 µM. The practical applicability of the proposed sensor was investigated using sample solutions prepared in tap water. The reported sensor showed impressive selectivity towards HQ and CT in the presence of common interferents.

The graphene-modified glassy carbon electrode (Gr/GCE) was fabricated by casting graphene (Gr). Some electrochemical parameters for diethylstilbestrol (DES) detection, such as pH, scan rate, and accumulation time were discussed. The interaction of DES with DNA at a Gr/GCE was studied by electrochemical method and factors influencing the interaction were optimized. Under the optimized conditions, the results revealed that the peak current decreased and the peak potential shifted to the positive side after adding DNA into the solution containing DES. We deduced that the interaction of DES with DNA mainly is intercalation. The interaction of DES with DNA was studied by ultraviolet and visible (UV-Vis) absorption spectroscopy. Also, with the addition of DNA, hyperchromic effect and small red shifts were observed in its UV-VIS spectra upon addition of DNA, results indicated that the DES molecule intercalated into the DNA, and the complex of DES-DNA was formed.

A new category of thermally stable hybrid polyarylidene(azomethine-ether)s and copolyarylidene(azomethine-ether)s (PAAP) based on diarylidenecycloalkanones has been synthesized using solution polycondensation method. For potential cationic sensor development, a thin layer of PAAP onto a flat glassy carbon electrode (GCE, surface area: 0.0316 cm2) was prepared with conducting nafion (5%) coating agent to fabricate a sensitive and selective arsenic (III) [As3+] ion in short response time in neutral buffer system. The fabricated cationic sensor was measured the analytical performances such as higher sensitivity, linear dynamic range, detection limit, reproducibility, and long-term stability towards As3+ ions. The sensitivity and detection limit were calculated as 2.714 μAμM−1cm−2 and 6.8 ± 0.1 nM (SNR of 3; 3N/S) respectively from the calibration curve. This novel approach can be initiated a well-organized route of an efficient development of heavy selective arsenic sensor for hazardous pollutants in biological, environmental, and health care fields. Real sample analysis for various environmental sample was performed with PAAP-modified-GCE.

In this work the electrochemical behavior of 6-mercaptopurine (6-MP) on MWCNT-CTAB modified glassy carbon electrode (GCE) is reported in a phosphate buffer solution, pH 3.0. Cyclic voltammetric studies indicated that the oxidation process is irreversible and diffusion-controlled. The number of electrons exchanged in the electro-oxidation process was obtained, and the data indicated that 6-MP is oxidized via a two-electron step. The results revealed that MWCNT-CTAB modified GCE promotes the rate of oxidation compared to the bare GCE, by increasing the peak current. The electron-transfer coefficients and heterogeneous electron-transfer rate constants for 6-MP were reported using modified GCE. A sensitive, simple, and timesaving linear sweep voltammetric procedure was developed for the analysis of 6-MP, using the MWCNT-CTAB/GC electrode. 6-MP can be determined with a detection limit of 8.41 × 10−9 M in the range of 5.0 × 10−7 M to 3.0 × 10−6 M with the proposed method. The developed method was successfully applied in real sample analysis. Keywords: Electrochemical method, 6-Mercaptopurine, Modified electrode, Detection limit, Calibration

For aluminum, a new visualization method is presented in which copper is deposited electrochemically. The fingerprint on the aluminum (trace carrier) serves as an insulator as it prevents direct contact between electrolyte and aluminum. The decisive factor is the choice of an ammoniacal copper sulfate solution, which acts as a corrosion inhibitor due to the ammonia molecules. This enables uniform copper deposition on aluminum and thus the development of a clearly defined negative image.

Antioxidants can reduce or inhibit damage such as oxidative decay caused by elevated levels of free radicals. Therefore, pursuing antioxidants with excellent properties has attracted more and more attention. Graphene quantum dots (GQDs) are considered a promising material because of their good free radical scavenging activity, low toxicity, and excellent water solubility. However, their scavenging efficiency, antioxidant mechanism, and effective control methods need to be improved. Herein, in order to further reveal the antioxidant mechanism of GQDs, the role of electrolytes in improving the antioxidant activity of GQDs is explored. In addition, 1,1-diphenyl-2-picrazine (DPPH∙), hydroxyl (∙OH), and superoxide (∙O2&minus, ) free radicals are used to evaluate the antioxidant activity of the as-prepared GQDs. Combined with transmission electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, and cyclic volt&ndash, ampere characteristic curves, the effects of an electrolytic environment on the surface functional groups, charge transfer capability, and defect states of GQDs are obtained. The antioxidant mechanism of GQDs and how to improve their antioxidant activity are further elucidated.

In this paper we report a low cost, simple, electrochemical method for large-area growth of single crystal ZnO nanorods. The method utilizes a metallic zinc foil as the source of the necessary zinc ions for ZnO growth on indium-doped tin oxide (ITO) glass slides. The method is thoroughly discussed and investigated varying all the parameters involved. The resulting ZnO nanorods are highly oriented along c-axis and densely packed, while their length and diameter can be tuned by varying the growth parameters. Two different types of seed layers on the ITO glass slides are tested. A seed layer made by spin coating of ZnO nanoparticles results in a twofold increase of the ZnO nanorod surface density as compared with a ZnO thin film seed layer by physical vapor deposition. Additionally, the effect of oxygen supply during electrodeposition was investigated as a crucial regulatory parameter not only for the geometrical and topological characteristics of the ZnO nano-arrays but for their physical properties as well.

IF=0.888; International audience; This article is mainly motivated by the growing needs for highly resolved measurements forwall-bounded turbulent flows and aims to proposes a spatial correction coefficient in order toincrease the wall-shear stress sensors accuracy. As it well known for the hot wire anemometry, thefluctuating streamwise velocity measurement attenuation is mainly due to the spatial resolution andthe frequency response of the sensing element. The present work agrees well with this conclusionand expands it to the wall-shear stress fluctuations measurements using electrochemical sensors andsuggested a correction method based on the spanwise correlation coefficient to take into accountthe spatial filtering effects on unresolved wall-shear stress measurements due to too large sensorspanwise size

A composite sensor consisting of two separate inorganic layers of Prussian blue (PB) and the composite of cerium oxide nanoparticles (CeNPs) and graphene oxide (GO), is tested with &bull, OH radicals. The signals from the interaction between the composite layers and &bull, OH radicals are characterized using cyclic voltammetry (CV). The degradation of PB in the presence of H2O2 and &bull, OH radicals is observed and its impact on the sensor efficiency is investigated. The results show that the composite sensor differentiates between the solutions with and without &bull, OH radicals by the increase of oxidation current in the presence of &bull, OH radicals. The redox response shows a linear relation with the concentration of &bull, OH radicals where the limit of detection, LOD, is found at 60 &micro, M (100 &micro, M without the PB layer). When additional composite layers are applied on the composite sensor to prevent the degradation of PB layer, the PB layer is still observed to be degraded. Furthermore, the sensor conductivity is found to decrease with the additional layers of composite. Although the CeNP/GO/PB composite sensor demonstrates high sensitivity with &bull, OH radicals at low concentrations, it can only be used once due to the degradation of PB.

Typical copper electrorefining electrolyte contains tens of grams of copper, some nickel and a wide variety of impurities. Some of these impurities comprise trace amounts of dissolved precious metals like Ag, Pd and Pt that currently are not fully exploited. This study presents an electrochemical method to recover precious metals via a combined electrodeposition-redox replacement (EDRR) process, where energy is used only to deposit copper during the ED-step, while the RR-step relies on the spontaneous replacement of copper by the precious metals (i.e. cementation). In order to conduct the recovery successfully, process parameters such as deposition potential (EDE), deposition time (tDE), redox replacement time (tRR) and the number of cycles (n) was adjusted. Investigations performed in synthetic electrolyte (40 g/L Cu, Ag = 10 ppm) proved the possibility to recover a high purity silver. Short deposition times (tDE) were found to result in small Cu particles that provided a suitably high surface area for silver cementation. In addition, experiments performed in real industrial electrolytes containing 44 g/L Cu and 54 ppb Ag (Boliden Harjavalta, Pori), demonstrated that EDRR could attain Ag recoveries of between 46–67% in an energy efficient, additive-free manner., The authors want to acknowledge NoWaste project, grant number: 297962 (VB, PH and KY) funded by Academy of Finland as well as GoldTail, grant number: 297962 (BW, ML). D.J thanks the National Centre for Research and Development, Poland (under the Lider program, Grant agreement LIDER/001/L-8/NCBR/2017). V.B would like to thank the Intramural CSIC incorporation project as well as research group of Hydrometallurgy and Corrosion in School of Chemical Technology of Aalto University. Academy of Finland funded “RawMatTERS Finland Infrastructure” (RAMI) based at Aalto University is greatly acknowledged.

The corrosion of steel tubes in sea water was controlled by cathodic protection. The impressed current technique was used. The rate of reaction was evaluated as a function of the temperature, pH and solution velocity. In this technique, the polarization method was used to determine the protection potential and current. The rate of zinc consumption, the protection potential, and the protection current are highly dependent on the variables of the study. The boundary element technique was suitable for modelling corrosion problems. The average percentage of error among the experimental and theoretical data was 1.27%.

Development of a rapid, sensitive and cost-effective method for toxicity assessment of commonly used nanoparticles is urgently needed for the sustainable development of nanotechnology. A neural cell with high sensitivity and conductivity has become a potential candidate for a cell chip to investigate toxicity of environmental influences. A neural cell immobilized on a conductive surface has become a potential tool for the assessment of nanotoxicity based on electrochemical methods. The effective electrochemical monitoring largely depends on the adequate attachment of a neural cell on the chip surfaces. Recently, establishment of integrin receptor specific ligand molecules arginine-glycine-aspartic acid (RGD) or its several modifications RGD-Multi Armed Peptide terminated with cysteine (RGD-MAP-C), C(RGD)₄ ensure farm attachment of neural cell on the electrode surfaces either in their two dimensional (dot) or three dimensional (rod or pillar) like nano-scale arrangement. A three dimensional RGD modified electrode surface has been proven to be more suitable for cell adhesion, proliferation, differentiation as well as electrochemical measurement. This review discusses fabrication as well as electrochemical measurements of neural cell chip with particular emphasis on their use for nanotoxicity assessments sequentially since inception to date. Successful monitoring of quantum dot (QD), graphene oxide (GO) and cosmetic compound toxicity using the newly developed neural cell chip were discussed here as a case study. This review recommended that a neural cell chip established on a nanostructured ligand modified conductive surface can be a potential tool for the toxicity assessments of newly developed nanomaterials prior to their use on biology or biomedical technologies.

Energy storage units have become important components in residential micro-cogeneration (MCG) systems. As MCG systems are often connected to single residences or buildings in a wide variety of settings, they are frequently unique and highly customized. Lithium-ion batteries have recently gained some profile as energy storage units of choice, because of their good capacity, high efficiency, robustness and ability to meet the demands of typical residential electrical loads. In the present work, modeled scenarios are explored which examine the performance of a MCG system with an internal combustion engine, photovoltaic input and a Li-ion storage battery. An electricity demand profile from new data collected in Ottawa, Canada is used to provide a full year energy use context for the analyses. The demands placed on the battery are examined to assess the suitability of the battery size and performance, as well as control related functionalities which reveal significantly varying battery use, and led to a quantitative expression for equivalent cycles. The energy use simulations are derived from electrochemical fundamentals adapted for a larger battery pack. Simulation output provides the basis for techno-economic commentary on how to assess large-scale Li-ion batteries for effective electrical storage purposes in MCG systems, and the impact of the nature of the control strategy on the battery service life.

Bentazone (BZ) is selective contact-past herbicide with suspected reproductive toxicity potential for human due to possible contamination of ground and surface waters. This work presents simple, rapid, sensitive and accurate determination of bentazone at unmodified boron-doped diamond electrode, using differential pulse voltammetry in Britton-Robinson buffer (pH 4, oxidation peak at 1.0 V). Under optimized DPV conditions linear calibration curve was obtained for range of 2 to 100 mu M, with a detection limit of 0.5 mu M. The effect of possible interfering agents is negligible, confirming good selectivity of the method. The method was successfully applied to determination of bentazone in spiked river water samples. This electrochemical determination of bentazone represents a favorable alternative to other used time-consuming and expensive analytical techniques and procedures. This is peer-reviewed version of the following article: Jevtić, S.; Stefanović, A.; Stanković, D. M.; Pergal, M. V.; Ivanović, A. T.; Jokić, A.; Petković, B. B. Boron-Doped Diamond Electrode — A Prestigious Unmodified Carbon Electrode for Simple and Fast Determination of Bentazone in River Water Samples. Diamond and Related Materials 2018, 81, 133–137. [https://doi.org/10.1016/j.diamond.2017.12.009] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3178]

A study of synthesis of multi-walled carbon nanotubes (MWNTs) and carbon sphere and also their electrochemical performance for the storage hydrogen gas has been presented. The structure and the morphology of carbon nanostructures have been investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy. Furthermore, the electrochemical hydrogen adsorption properties of MWNTs and carbon spheres were elucidated by galvanostatic charge/discharge and cyclic voltammetric measurements. The electrochemical results demonstrated that carbon spheres synthesized from sucrose and starch exhibited hydrogen adsorption of ∼0.9 and 1 wt% respectively. Whereas, the multiwalled carbon nanotubes have exhibited hydrogen adsorption of ∼1.2 wt%.

A new method is developed for synthesizing Ti4O7 supported Ru@Pt core–shell catalyst (Ru@Pt/Ti4O7) through pyrolysis followed by microwave irradiation. The purpose is to improve the Ru durability of PtRu from core–shell structure and strong bonding to Ti4O7 oxide. In this method, the first step is to co-reduce the mixture of ruthenium precursor and TiO2 in a H2 reducing atmosphere under heat-treatment to obtain a Ru core on Ti4O7 support, and the second step is to create a shell of platinum via microwave irradiation. Energy dispersive X-ray spectrometry, X-ray Diffraction, High-resolution Scanning Transmission Electron Microscopy with the high-angle annular dark-field method and Electron Energy-Loss Spectroscopy are used to demonstrate that this catalyst with larger particles has a core–shell structure with a Ru core and a Pt shell. Electrochemical measurements show Ru@Pt/Ti4O7 catalyst has a higher CO-tolerance capability than that of PtRu/C alloy catalyst.

In this study, two layers: i-ZnO nanorods and p-Cu2O were fabricated by electrochemical deposition. The fabricating process was the initial formation of ZnO nanorods layer on the n-IGZO thin film which was prepared by sputtering method, then a p-Cu2O layer was deposited on top of rods to form the p-Cu2O/i-ZnO nanorods/n-ZnO heterojunction. The XRD, SEM, UV-VIS, I-V characteristics methods were used to define structure, optical and electrical properties of these heterojunction layers. The fabricating conditions and thickness of the Cu2O layers significantly affected to the formation, microstructure, electrical and optical properties of the junction. The length of i-ZnO nanorods layer in the structure of the heterojunction has strongly affected to the carriers transport mechanism and performance of this heterojunction.

ObjectivesAn experimental rabbit model was used to test the null hypothesis, that there is no difference in new bone formation around uncoated titanium discs compared with coated titanium discs when implanted into the muscles of rabbits.MethodsA total of three titanium discs with different surface and coating (1, porous coating; 2, porous coating + Bonemaster (Biomet); and 3, porous coating + plasma-sprayed hydroxyapatite) were implanted in 12 female rabbits. Six animals were killed after six weeks and the remaining six were killed after 12 weeks. The implants with surrounding tissues were embedded in methyl methacrylate and grinded sections were stained with Masson-Goldners trichrome and examined by light microscopy of coded sections.ResultsSmall amounts of bone were observed scattered along the surface of five of the 12 implants coated with porous titanium, and around one out of 12 porous coated surfaces with Bonemaster. No bone formation could be detected around porous coated implants with plasma-sprayed hydroxyapatite.ConclusionPorous titanium coating is to some degree osteoinductive in muscles.

The features of the corrosion process in the artificial defect on the coating obtained by plasma electrolytic oxidation (PEO) method on magnesium MA8 alloy have been investigated using the Localized Electrochemical Impedance Spectroscopy (LEIS), Scanning Vibrating Probe (SVP) techniques along with the Non-Contact Optical Surface Profiler (OSP) technique. The analysis of the experimental data enabled us to suggest that the corrosion process in the defect zone developed predominantly at the magnesium/coating interface. The LEIS technique allows detecting the precision alterations result from corrosion process, which cannot be found by optical image. The data processing has demonstrated a good correlation between the results obtained by a group of methods at all stages of the corrosion process.

In the paper authors present results of an experimental investigations of two phase flow across staggered and in-line tube bundles. Flow visualization and velocity distribution were obtained with the use of DPIV technique. Electrochemical, limiting current method was used to measure values of convective mass transfer and Chilton-Colburn heat-mass transfer analogy was applied to obtain Nusselt number distribution around tube surface.

Amperometric hydrogen peroxide (H2O2) and glucose biosensors based on unzipped carbon nanotubes with modified glassy carbon electrode (GCE) have been successfully fabricated via a facile electrochemical oxidative method. In this work, we investigated the feasibility of this new form of carbon nanomaterial as a substrate electrode material for fabricating sensitive platform for H2O2 and glucose sensors. For this purpose, the manganese oxide (MnO2)/unzipped single-walled carbon nanotubes (SWCNTs) film was synthesized by the cyclic voltammetry method. The developed sensing film, MnO2/unzipped SWCNTs/GCE, displayed a satisfactory analytical performance for H2O2, including a wide linear range of 2.0 &times, 10&minus, 6 to 5.0 &times, 3 M with a detection limit of 0.31 &times, 6 M (10.7 ppb). This film was further applied for glucose sensing with a linearity range of 0.01 to 1.2 mM with a correlation coefficient of 0.9822 in the physiological pH (7.4). This facile, fast, environmentally-friendly, and economical preparation strategy of carbon nanomaterial-based electrode materials opens up the possibility of developing high quality biocompatible hydrogen peroxide and glucose sensors.

Cyclic voltammetric methods have been applied to study the electrochemical behavior of the sulfide minerals in phosphate-buffered alkaline solution. The redox process of electrodes of sulfide ores was investigated using silicone-impregnated graphite electrode. The cathodic and anodic reaction products in alkaline solution were determined within the potential range of -2V to +2V (vs. Ag/AgCl). The several successive measurement cycles’ voltammograms leads to the appearance of a new anodic peak at E = 450mV, which is absent in the first cycle and curves, as well as other features that appear in cycling, can probably be explained by secondary electrochemical transformations of the products formed by the oxidation of the original pyrite at the interface between the electrode material.DOI: http://doi.dx.org/10.5564/mjc.v15i0.318 Mongolian Journal of Chemistry 15 (41), 2014, p33-35

Steel-corroding protection has been one of the most important research fields because of the great significance of steel in national defense, industry and our daily life. In the presented work, a novel corrosion inhibitor and its corrosion-inhibiting performance which was determined by an electrochemical approach supported with weight-loss method were reported. The presented inhibitor, i.e., palmitic acid polyacrylamide, was synthesized via a requrqitant condensation route in the presence of palmitic acid, ethylenediamine and dimethyl benzene. The optimal preparing conditions were obtained by orthogonal experiments, and the corrosion-inhibiting property of palmitic acid polyacrylamide at different concentration was also investigated. The results show that the corrosion-inhibiting efficiency was up to 78.1%, indicating its potential application for protecting steel from corrosion in national defense, industry and our daily life.

Organic complexation in atmospheric precipitation is an important control mechanism of the biogeochemistry of metal ions. We have measured complexation of copper ions in bulk precipitation by the method of differential pulse anodic stripping voltammetry (DPASV), which introduces least perturbation in the samples. The precipitation samples were collected periodically during one year in the mainland area of Croatia (Zagreb) and at the Adriatic coast (Šibenik). The results have shown the complexation of copper ions in all the samples. The method of determination presumes the existence of 1:1 copper ion - ligand complexes. The complexing capacity of rainwater samples for copper ions ranged between 0.010 and 1.4 &micro ; M. The highest capacity was measured in April 2003 in rainwater sample from the Šibenik area, which could be associated to the contribution of biogenically driven organics to marine aerosol. Apparent stability constants determined were in the range of 6.1 -10. The sources of organic ligands in the samples could be multiple. The concentrations of dissolved organic carbon (DOC) as well as of surface active substances (SAS) were measured. The proportion of complexing ligands in these two organic matter fractions has also been discussed.

Mesoporous gold (Au) films with tunable pores are expected to provide fascinating optical properties stimulated by the mesospaces, but they have not been realized yet because of the difficulty of controlling the Au crystal growth. Here, we report a reliable soft-templating method to fabricate mesoporous Au films using stable micelles of diblock copolymers, with electrochemical deposition advantageous for precise control of Au crystal growth. Strong field enhancement takes place around the center of the uniform mesopores as well as on the walls between the pores, leading to the enhanced light scattering as well as surface-enhanced Raman scattering (SERS), which is understandable, for example, from Babinet principles applied for the reverse system of nanoparticle ensembles., The selective growth of mesoporous gold thin films with control over the porosity is a challenging task. Here, the authors report a soft-templating method allowing the growth of tunable, mesoporous gold films and examine their optical properties

Dans cette étude, des mesures électrochimiques ont été utilisées pour caractériser l'efficacité inhibitrice du produit commercial Kemazur 1620, employé pour le traitement des eaux des circuits de refroidissement. L'influence de la concentration de ce composé ainsi que l'effet de la température du milieu ont été étudiés.Les courbes de polarisation ont été obtenues à l'aide d'un montage à trois électrodes. La méthode électrochimique a permis de déterminer la vitesse de corrosion en l'absence et en présence d'inhibiteur et par conséquent, le taux de protection. Ainsi, le Kemazur 1620 présente une très bonne efficacité pour une concentration de 2000 ppm. Entre 1000 et 2000 ppm, l'efficacité inhibitrice augmente de 56 à 91 %. En outre, l'efficacité inhibitrice du composé a été comparée à celle du nitrite de sodium., In this study, electrochemical measurements were carried out to characterize the inhibition efficiency of the commercial product Kemazur 1620, employed for water treatment in cooling circuits. The influence of parameters such as the concentration of the compound and the effect of the temperature on the behavior of the carbon steel / corrosion medium interface was studied. Polarization curves have been obtained by a three-electrode device. In the first part of this study, only the evolution of the corrosion rate as a function of concentration was examined. It has been shown from the polarization curves that the Kemazur 1620 presents a very good efficiency for a concentration of 2000 ppm. Between 1000 and 2000 ppm, the inhibition efficiency increases from 56 to 91 %. In a second part, the inhibition efficiency of the compound has been compared to an inhibitor used for similar uses.

Depending on where ozone resides, it can protect or harm life on Earth. The thin layer of ozone that surrounds Earth acts as a shield protecting the planet from irradiation by UV light. When it is close to the planet's surface, ozone is a powerful photochemical oxidant that damage, icons frescos, museum exhibits, rubber, plastic and all plant and animal life. Besides the basic properties of some methods for determining the ozone concentration in working and living conditions, this paper presents a detailed description of the electrochemical method. The basic properties of the electrochemical method are used in the construction of mobile equipment for determining the sum of oxidants in the atmosphere. The equipment was used for testing the determination of the ozone concentration in working rooms, where the concentration was at a high level and caused by UV radiation or electrostatic discharge. According to the obtained results, it can be concluded that this equipment for determining the ozone concentration in the atmosphere is very powerful and reproducible in measurements.

Vertically aligned single-crystal InSb nanowires were synthesized via the electrochemical method at room temperature. The characteristics of Fourier transform infrared spectrum revealed that in the syntheses of InSb nanowires, energy bandgap shifts towards the short wavelength with the occurrence of an electron accumulation layer. The current–voltage curve, based on the metal–semiconductor–metal model, showed a high electron carrier concentration of 2.0 × 1017 cm−3 and a high electron mobility of 446.42 cm2 V−1 s−1. Additionally, the high carrier concentration of the InSb semiconductor with the surface accumulation layer induced a downward band bending effect that reduces the electron tunneling barrier. Consequently, the InSb nanowires exhibit significant field emission properties with an extremely low turn-on field of 1.84 V μm−1 and an estimative threshold field of 3.36 V μm−1.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2013, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2013, Çinko ve nikel kaplamalı malzemelerin korozyon davranışı ile ilgili bilgi sahibi olmak için kullanılan yöntemler oldukça uzun süreler gerektirmekte ve objektif veriler elde edilememektedir. Elektrokimyasal Empedans Spektroskopisi (EIS) yöntemi, korozyonu sayısallaştırarak mevcut yöntemlerden farklı olarak test sonuçlarının objektif bir şekilde değerlendirilebilmesine olanak sağlamaktadır. Ayrıca farklı çalışma ortamlarında ve farklı geometriye sahip parçalarda da kaplama performansı test edilebilmektedir. Bu tez çalışması kapsamında, yaklaşık 25 cm2 boyutlarında DC03 kalite düşük karbonlu çelik plakalar üzerine farklı kaplama sürelerinde elektrolitik çinko ve nikel kaplamalar yapılarak, bunların tuzlu su sisi testi ile polarizasyon dirençleri arasında bir ilişki kurulmaya çalışılmıştır. Bu bağlamda, kaplama firmalarından çinko ve nikel kaplamalar için elektrolitik kaplama öncesi kullanılan temizleme çözeltileri ve proses banyoları temin edilmiş, laboratuvar ortamında bu proses banyoları kullanılarak çelik plakalar üzerine farklı kalınlıklarda çinko ve nikel kaplamalar gerçekleştirilmiştir. İlk seri kaplamaların kalınlıkları Fischerscope XDL kalınlık ölçüm cihazı kullanılarak tahribatsız olarak ölçülmüştür. İkinci seri kaplamalarda ise mevcut kaplama kalınlıkları, numuneden kesit alınıp optik mikroskopta incelenerek tespit edilmiştir. Tuzlu su sisi testleri ASTM B117 standardına uygun olarak Weiss SC450 kabin kullanılarak yapılmıştır. I.seri plakalarda yapılan tuzlu su sisi testlerinde numuneler 30dk aralıklarla korozyon açısından kontrol edilmiştir. II.seri plakalarda korozyon verisini sayısallaştırmak amacıyla şablonlar oluşturulmuş, çinko kaplamalı plakalar için beyaz pas görülen kare adedi ile nikel kaplamalar için birim alandaki oyuk miktarı olarak değerlendirilmiştir. Çinko kaplamalı vidalar için kaplamanın en ince bölgesinin tayini için kullanılan bakır sülfat testi yapılarak korozyon dayanımı hakkında öngörülerde bulunulmuş ve bu doğrultuda EIS testleri ile doğrulanması amaçlanmıştır. Nikel kaplamalı plakalarda ve taban malzemede yüzey pürüzlülüğü ölçülmüş, kaplama kalınlığı ve polarizasyon direnci ile ilişkilendirilmiştir. Nikel kaplamalı vidalar için porozitenin tayinine yönelik modifiye sıcak su testi yapılmış, testten geçen ve kalan vidalara test öncesi ve sonrası EIS testi yapılarak, porozite tayini ile korozyon ömrü arasında ilişki kurulmaya çalışılmıştır. EIS testi atmosfere açık ortamda ve oda sıcaklığında olacak şekilde %3,5 NaCl çözeltisi içerisinde gerçekleştirilmiştir. Çalışma sonunda, çinko kaplanmış plakaların tuzlu su sisi testinde görülen hata miktarı ile polarizasyon dirençleri arasında ömür tayinine yönelik ilişki kurulabilmiştir. EIS testi ile mevcut korozyon testlerinin korelasyonu yapılarak ikinci aşama olan çinko kaplamalı vidalar için kaplama kalınlığı hakkında bilgi vermekte olan testler uygulanmıştır. Bu testlerden geçen ve kalan vidalar için EIS testleri uygulanarak bakır sülfat testinin çinko kaplamalı vidalarda hızlı bir ön değerlendirme olarak kullanılabileceği görülmüştür. Nikel kaplanmış plakalarda 6 saatlik test süresinin literatürde de karşılaşıldığı üzere kaplama üzerinde pasif film oluşmasından dolayı yetersiz kaldığı görülmüş, bundan dolayı test süresinin 30 saate kadar uzatılması gerektiği sonucuna varılmıştır. Yüzey pürüzlülüğünün nikel kaplamalar için korozyon ömrü bakımından çok etkili bir parametre olduğu görülmüş, kaplama kalınlığı ile açıklanamayan polarizasyon direnci değişimlerinde yüzey pürüzlülüğünün etkili olduğu anlaşılmıştır. Nikel kaplamalı vidalarla gerçekleştirilen modifiye sıcak su testi ile EIS ölçümleri sonucunda porozitenin korozyon ömrüne etkisi görülmüştür. Her iki kaplama için de banyo çözeltisindeki metal miktarının kaplamanın kalınlığına olan etkisi, banyo çözeltisine çinko veya nikel takviyesi yapılmasından önce ve sonra alınan banyo çözeltileriyle yapılmış olan kaplamalar aracılığıyla anlaşılmıştır., The use of metal has increased day by day and at the same time the loss of materials and manpower caused by metal corrosion has reached serious proportions. The metallic coating was applied to solve this problem because of its easy practice and success in improvement the service life. Metallic coatings became an important and necessary method to improve surface properties of the base metals, which exhibit limited corrosion, wear and oxidation resistances. Zinc and nickel coatings are used succesfully for many years for protection of ferrous alloys against corrosion attack. In addition to the coatings, the passivation process draw the attention for a decorative appearance, while providing enhancement in the corrosion resistance. There are limited number of studies about the prediction of service life of protective coatings. In these studies, EIS measurements have performed in different operating environments in order to determinate the lifetime of the coatings’ and to establish a relationship between the other corrosion test results. Studies in this area showed that when the polarization resistance of coatings drop below 107 , the corrosion resistance severely damaged. Hence, in this thesis the relationship between polarization resistance values obtained from EIS measurements and salt spray test values were correlated. Generation of defects in salt spray test was accompanied by a reduction in polarization resistance. The methods for determination of corrosion behavior of the zinc and nickel coated materials need very long time periods and may not present an objective data. In contrast to the existing methods, Electrochemical Impedance Spectroscopy (EIS) method allows the evaluation of test results objectively by digitizing progress. In addition, components that have different geometry can be tested in different operating environments. In this thesis,electrolytic zinc and nickel coatings applied on DC 03 quality low-carbon steel sheets in different coating times and tried to establish a relationship between their salt spray test and the polarization resistance. The cleaning solutions that are used before electroplating process were also obtain from the relevant industrial companies. Zinc coating was performed for 13,5 and 15 min. Nickel coating was performed for 8, 10, 13, 15 and 18 min after 1-min copper plating. The thickness of the coatings were measured by Fischerscope XDL thickness measurind device and optical microscope. Electrolytic bath solutions were obtained from the relevant coating companies. Since the zinc and/or nickel contents of the electrolytes were reduced as they have been used in the coating operations, metal ion concentrations of the electrolytes were adjusted at certain intervals by adding zinc and/or nickel. Therefore in the present study with or without addition of these metals were utilized in order to analyze the effect of metal ion concentration of the electrolytes. EIS test was applied according to the principle of three-electrodes. The saturated calomel electrode was used as the reference electrode, the graphite rod was used as the counter electrode and plates coated with zinc or nickel were used as the anode. Working life of coatings without progress of corrosion correlated with estimated porosity. EIS test was performed at room temperature in 3,5% NaCl solution. EIS measurements were performed by using the Voltmaster 4 program with the Voltalab 40 PGZ 301 device. Measurements were performed at the frequency range of 100kHz-10mHz and the EIS graphics were obtained in the Bode form. Salt spray tests were made by using Weiss SC450 cabin in accordance with ASTM B117 standard. In order to quantify the performances of coatings, coating surfaces paterned in forty squares.The number of white rust frame was evaluated for zinc-coated plates and amount of pit was counted for nickel -coated plates. The ratio of the defects generated in salt spray test on the zinc coatings were correlated with the polarization resistance to estimate working life. Number of defects in salt spray test have been identified in response to a significant decrease in the value of polarization resistance. The copper sulfate test were conducted to correlate the results with EIS tests used to find the thinnest spot of the zinc coating screws. The copper sulfate solution was prepared by dissolving approximately 36 parts of commercial cupric sulfate crystals (CuSO4.5H2O) by weight in 100 parts of distilled water. The prepared solution then heated to add 0.8 g/L cupric oxide (CuO). Specimens were immersed in the copper sulfate solution which maintained at a temperature of 16 to 20˚C. Specimens were remained in a fixed position in the solution for exactly 1 min. After each 1-min immersion, specimens were washed in the rinse water to remove any copper deposit that might be present on zinc coatings. This process was repeated until the end point has been reached. Modified hot water test applied to the nickel-coated screws to determine the porosities present in the coatings. The screws immersed in 90˚C salty distilled water (~ 0.5 % NaCl solution) for two hours. Two-hours test period started when the water temperature was reached the temperature at 90˚C. At the end of the test period, screws was removed from the hot water and was dried with the air. EIS test applied to screws after the hot water test. Following results were obtained from the experiments conducted in the present study. • In order to make correlation between salty water and impedance test results for corrosion life of coatings, the results of the corrosion test should be quantified. In this respect, present study showed that number of white rust per unit area and number of pits per unit area should be considered for zinc and nickel coatings respectively. • The EIS test conducted immidiately after immersing the sample in solution did not give sufficient information about corrosion resistance of the coatings. Therefore EIS graphics should be obtained after holding the samples in the solutions for certain time period. • For the zinc-coated plates increase in number of defects after salt spray tests accompanied by a reduction in polarization resistance. These results indicated that a correlation can be established between salt spray and EIS tests for corrosion life of zinc coatings. • For the nickel coated plates, holding time in salty water shorter time 5-hour leaded corrosion, whose progress was not identified clearly by EIS tests. In the literature it has been reported that corrosion resistance of nickel coatings were poor at the beginning of the tests and tended to increase with holding time especially after 30 min to 4 hours. Longer holding times companied by a reduction in corrosion resistance. Since similar results have been obtained in the present study, the correlation between EIS and salt spray test have been made after holding the samples in salty water for 30 hours. • If EIS tests for nickel-coated plates continue until the breaking point of polarization resistance, the effect of the passive layer on the coating can be avoided. Polarization resistance may provide information about the corrosion mechanism of the samples with complex geometry, other than flat plates. Determined by the polarization resistance value will be accepted and with movement of the polarization resistance at time zero, corrosion life or the sample can be determined. • For the nickel coated plates, the increase of copper flash and nickel thickness cause increase of polarization resistance. Higher surface roghness values leaded reduction of polarization resistance. • EIS tests which conducted on the zinc-coated screws, after copper sulfate test, revealed the limit value of polarization resistance. Zinc-coated samples should exhibit polarization resistance value higher than 4,2 E8 Ω for required corrosion performance. If the number of EIS tests of zinc-coated screws increase at time zero, a database can be prepared. The database of polarization resistance values may give information about coatings’ life prediction. • Modified hot water test has been developed for pass/fail criteria of nickel coated screws. The limit polarization resistance has been determined as 4,5 E8 Ω for nickel-coated samples. • With increasing the number of tests (modified hot water tests for nickel coatings and copper sulphate tests for zinc coatings) of screws by comparing with EIS test results may provide more information about the complex geometry brought dispersion., Yüksek Lisans, M.Sc.

In this work, a bipolar packed bed electrolytic cell having steel Raschig rings behaving as electrodes has been used to remove chromium in the form of Cr(VI) from aqueous solutions and a sample of plating bath rinse. Fe2+ ions generated at the anode side of the electrodes have reacted with OH‐ ions generated at the cathode side forming Fe(OH)2 in this electrolytic cell.Cr(VI) have coprecipitated as Cr(OH)3 with Fe(OH)3 forming after the redox reaction between Fe(OH)2 and Cr(VI). Meanwhile other impurities have also removed besides Cr(VI) using this process. Removal rate of 100% for Cr(VI) has been achieved in the experiments done with different initial Cr(VI) concentration, duration of electrolysis and applied potential. Fully removal of Cr(VI) has also been achieved from the sample of plating bath rinse.

A novel iridium complex, [bis-(2-phenylpyridine)(2-carboxy-4-dimethylaminopyridine)iridium(III)] (N984), was synthesized and characterized using spectroscopic and electrochemical methods; a solution processable OLED device incorporating the N984 complex displays electroluminescence spectra with a narrow bandwidth of 70 nm at half of its intensity, with colour coordinates of x = 0.322; y = 0.529 that are very close to those suggested by the PAL standard for a green emitter. Bolink, Henk, Henk.Bolink@uv.es ; Coronado Miralles, Eugenio, Eugenio.Coronado@uv.es ; Garcia Santamaria, Sonsoles Amor, Sonsoles.Garcia@uv.es

Bilayer electrolytes made of barium cerate covered with a thin film of barium zirconate deposited by pulsed laser deposition show promise for improving chemical stability without greatly affecting electrochemical performance in fuel cell operation.