Sulfate Bath Research Articles

An electrochemical technique for fabrication of Mn-54 sources towards characterization of gamma counting nuclear instruments

Long lived sealed radioactive sources are used for the energy calibration and efficiency determination of counting systems used in the nuclear sector. Using a sulphate bath, a facile electrochemical method was developed by electrodeposition of 54Mn on 5 mm (φ) stainless steel substrates for the preparation of 54Mn sources for such uses. Inactive sources prepared under suitable experimental parameters characterized by XRD revealed that manganese is deposited in oxide form. SEM and EDS analyses of electrodeposited surfaces confirmed uniform distribution of elements and the absence of fractures, flaws, and spatial variations. Cyclic voltammetry (CV) scans provided information about the electrochemical processes involved in the deposition process. Uniform distribution of radioactivity on surface of source was ascertained by autoradiography. Swipe tests of the encapsulated sources confirmed negligible removable surface contamination. The 54Mn sources containing up to 185KBq of 54Mn on stainless steel discs were prepared. These sources along with other longer lived sources were supplied to various users as a package of radiation sources for characterization of gamma counting systems over a wide energy range.

Fabrication of Roughened Electrodeposited Copper Coating on Steel for Dissimilar Joining of Steel and Thermoplastic Resin

Electrodeposition of a roughened copper coating onto steel was carried out to produce a bonding surface for thermoplastic resin (polyphenylenesulfide). The roughened copper film was electrodeposited using a copper sulfate bath containing polyacrylic acid (PAA). Following injection molding of the resin, the bonding strength was evaluated in a tensile lap shear strength test, followed by durability testing at high temperature and humidity (85 ± 2 °C and 85 ± 2% relative humidity, respectively) for 2000 h, and a thermal shock test (−50 °C–150 °C) for 1000 cycles. An analysis of the boundary microstructure showed that the PAA concentration had a large effect on the surface morphology of the copper film. The shear strength of the joint between the coated steel substrate and the resin was more than 40 MPa, and the bonding strength also remained above 40 MPa throughout the durability test. During the thermal shock test, although the bonding strength gradually decreased with increasing number of cycles, it remained at over 20 MPa, even after 1000 cycles. This method achieves not only high initial bonding strength, but also durability for joints between dissimilar materials such as steel and resin.

Impact of Cathodic Potential on the Growth Mechanisms and Morphology of Ni–P Alloys Using Electrodeposition Technique

Phosphorus nickel alloy, intended for anticorrosion coating, was prepared and deposited at room temperature on copper substrate by chronoamperometry technique in a sulphate bath. The effect of potential on the chemical composition, nucleation and growth, the structure and surface morphology during the electrodeposition of this alloy was presented in this work. X-ray microanalysis showed that the content of phosphorus in the prepared alloys decreases with increasing cathodic potential. Chronoamperograms analysis indicated that the nucleation process is instantaneous and of three-dimensional (3D) growth and is controlled by kinetics. X-ray diffraction analysis revealed an amorphous structure while SEM images showed a smooth appearance with pore presence.

Impact of ionic liquid [FPIM]Br on the electrodeposition of Ni and Co from an aqueous sulfate bath

A novel ionic liquid, namely, 1-(4-fluorobenzyl)-3-(4-phenoxybutyl)imidazole-3-ium bromide [FPIM]Br, was used as an additive for cobalt (Co) and nickel (Ni) electrodeposition from acidic sulfate and Watts baths, respectively. The effect of [FPIM]Br on the electrodeposition mechanism of the coatings was investigated by a variety of electrochemical methods (potentiodynamic cathodic polarization, cyclic voltammetry, and anodic linear stripping voltammetry) as well as by morphologic techniques (XRD, SEM, EDX and AFM). The inhibition of Co2+ and Ni2+ ions deposition in the presence of [FPIM]Br was found to lead to finer-grained deposits. Adsorption of [FPIM]+ on the copper substrate is shown, and the process obeys the Langmuir adsorption isotherm. The cathodic current efficiency (CCE%), hardness and corrosion resistance for Co2+ and Ni2+ deposition in the electrodeposition bath were found to increase when additive was included. The resultant surface morphologies demonstrated that the [FPIM]Br additive served as an effective brightener that can produce highly uniform and smooth Co and Ni deposits.

On the temperature dependent magnetization in dual-phase Co nanowires confinedly electrodeposited inside nanoporous alumina membrane

The present paper reports the temperature dependent magnetization in dual-phase Co nanowires electrodeposited inside nanoporous alumina membrane. The Co nanowires were grown inside the nanochannels of the alumina membrane using an acidic sulphate bath (pH 3). Phase analysis, in combination with magnetic measurements, confirmed the mixed-phase structures as hcp and fcc-Co. The dominant fcc-Co phase appears with a minor hcp-Co phase having major c-axis orientation perpendicular to the nanowire axis. The role of phase structures and the interplay of magnetic anisotropies have been discussed to understand the temperature dependent magnetization of these dual-phase Co nanowires embedded inside alumina membrane. The temperature dependent reorientation of easy magnetization axis and the resulting magnetic properties could be ascribed to the magneto-structural coupling for such confinedly grown Co nanowires.

Electrodeposition of Zn-Co Alloy from an Acid Sulphate Bath Containing Triethanolamine and Thiaminehydrochloride

Electrodeposition of Zn-Co alloy from an acid sulphate bath has been carried out in this research work. The effects of metal ion ratio in the bath, pH current density, temperature, stirring, thickness and concentrations of triethanolamine and thiaminehydrochloride on the alloy composition and on cathodic current efficiency have been investigated. The deposition potentials of Zn-Co alloy are less noble of zinc and cobalt. The structure of Zn-Co alloy was investigated by X-ray diffraction indicates zinc structure. The surface morphology of alloy deposits is found to depend on the percentage of cobalt in the alloy. Under the optimum operating conditions, Zn-Co alloy deposition follows anomalous co-deposition.

Physico-Chemical Properties of Zn-Fe Alloy Deposits from an Acid Sulphate Bath Containing Triethanolamine

The composition, properties, structure and morphology of electrodeposited Zn-Fe alloy deposits obtained from an acid sulphate bath containing triethanolamine have been investigated. A bath containing less zinc (20%) produced an alloy deposit with higher zinc content (80%), i.e. anomalous co-deposition process. The composition of alloy remained constant with pH of the plating bath and thickness of the alloy deposit. The cathodic current efficiency depends on plating variables. The shift in deposition potentials of Zn-Fe alloy is a chief cause in the co-deposition process to produce alloy of varying composition. Phase structure determination by X-ray diffraction studies showed a wide variety of inter metallic phases. Zn-Fe alloy showed a superior corrosion resistance than zinc coatings. An alloy containing greater than 40% Fe showed a good paintability. Hardness of the alloy deposits increased with increase in iron content in the alloy. Smooth, uniform and fine grained deposits were obtained for the Zn-Fe alloy containing 20% Fe.

Effect of Baking on Hydrogen Embrittlement for High Strength Steel Treated with Various Zinc Based Electroplating from a Sulfate Bath

The hydrogen embrittlement of SK85 high-strength steel sheets was evaluated using a three-point bending test. The effects of electroplating each with zinc, zinc–SiO2, zinc–nickel, and zinc–nickel–SiO2 on hydrogen embrittlement were examined by baking the electroplated steel specimen. Each electroplating type caused hydrogen embrittlement, which was promoted by hydrogen, owing to the reduction due to hydrogen ions during electroplating. The hydrogen embrittlement of both zinc-electroplated and zinc–SiO2-electroplated SK85 steel continued after baking for 24 hours at 200°C, but that of the zinc–nickel-electroplated and zinc–nickel–SiO2-electroplated SK85 steel ceased. Furthermore, TDA revealed that the diffusible hydrogen at approximately 200°C, which was caused because of hydrogen embrittlement, was desorbed from all the electroplated specimens before the baking. However, after the baking, this diffusible hydrogen for each specimen was not desorbed. These results indicate that the hydrogen embrittlement for zinc-based electroplated high-strength steel was caused by another factor except for diffusible hydrogen. The hydrogen formed due to the electroplating was incorporated in the steel substrate, following which the hydrogen-vacancy cluster was formed in the substrate. It seems that the zinc and zinc–SiO2 film provided insufficient permeability required for the formation of the hydrogen-vacancy cluster. However, zinc–nickel and zinc–nickel–SiO2 film enabled hydrogen-vacancy cluster diffusion from the substrate.

In Situ Growth Characterization of Electrodeposited Metal Contacts

We have developed a new electrochemical method to study the morphology of electrodeposited metal in-situ at the nano-scale , without the need of any additional surface characterization techniques. A metal-insulator-metal (MIM) pillar structure with exposed edges is fabricated and subsequently contacted in a customize 4-electrode electrochemical cell. The current is measured during electrodeposition while a voltage bias is applied between the two working electrodes, separated by a 50 nm thin dielectric. For appropriate choices of the voltage bias and deposition potential, the current between the two working electrodes can easily be distinguished from the electrodeposition current. This current represents the tunnelling current and eventually the mesoscopic contact current. The change in conductance of the MIM structure during electrodeposition is highly indicative of the growth mode of the electrodeposited metal. A rough film growth leads to step-like, quantized current transients typical of mesoscopic point contacts. Some steps correspond to the conductance quantum but smaller steps in the tunnelling current are also observed [1]. In contrast, a uniformly growing film leads to smooth, exponential current transients due to the significant contribution of a tunnelling current before physical contact is made.We use this method to investigate the growth of Au thin films from a thiosulfate-sulfite bath, and the growth of Cu from a sulfate bath. We also show the effect of common levelling additives for Cu electrodeposition, such as polyethylene glycol (PEG) and benzotriazole (BTA). Additionally, we have observed a significant dependence of the film growth on the voltage bias applied between the top and bottom metals of the MIM that is independent of the deposition potential.This technique provides a novel platform to study the effect of additives and other electrodeposition variables in a wide range of electrolytes. Furthermore, it provides an efficient platform to fabricate nanogap structures.[1] Li, C. Z., H. X. He, and N. J. Tao. "Quantized tunneling current in the metallic nanogaps formed by electrodeposition and etching." Applied Physics Letters 77.24 (2000): 3995-3997.

Atomistic State of Hydrogen in Electrochemically Deposited Cu Films

Electro and electroless deposition of Cu films are widely used in the print circuit boards production. These electrochemical Cu deposition process are accompanied with the simultaneous hydrogen evolution, and the hydrogen co-deposition sometimes causes the voids and blisters1). However, the detail mechanism of such hydrogen-induced phenomena have not been clarified. We previously reported that the primary cause of the room-temperature grain growth observed in electrodeposited Cu films was the formation of superabundant vacancies induced by the hydrogen co-deposition2). In this study, the atomistic state of hydrogen co-deposited in the Cu films obtained by electro and electroless deposition and the influence of hydrogen on the microstructure of Cu films were investigated.Cu films were electrodeposited from six different baths (sulfate bath, additive-containing bath, chloride bath, pyrophosphate bath, EDA bath, and EDTA bath) and electrolessly deposited from an EDTA bath. The amount and atomistic state of hydrogen in the Cu films were analyzed by thermal desorption spectroscopy (TDS). The microstructural analysis of the Cu films was performed by X-ray diffraction (XRD) and transmission electron microscopy (TEM).In the electrodeposited Cu films with high hydrogen concentrations (x = H/Cu = 5.4 ~ 98.2×10-4), the room-temperature grain growth proceeded with the desorption of hydrogen during 7 ~ 21 days after deposition2). A pronounced desorption peak at 600 ~ 700 K due to the break-up of vacancy-hydrogen clusters3) was observed in the thermal desorption spectra of hydrogen from these Cu films.In the thermal desorption spectra of hydrogen from electrolessly deposited Cu films, a pronounced peak at around 420 K and a small peak at 600 ~ 700 K were observed and the hydrogen concentration was x = 13.6×10-3. From the XRD measurements, the lattice expansion of about 0.14% was observed in the as-deposited Cu films, which was reduced with the desorption of hydrogen at room temperature after 7 days. These results suggest that the desorption peak at 420 K may be assigned to the desorption of hydrogen from the regular interstitial sites. In the TEM images of these Cu films, many nano-voids distributed in the crystal grains were observed. We consider that the hydrogen molecules trapped in the nano-voids should be desorbed at high temperature above 900 K. The high-temperature TDS measurements will be performed. References 1) T. Sharma, A. E. Landry, A. Leger, D. A. Brown, T. Bernhard, S. Zarwell, F. Brüning, and R. Brüning, Thin Solid Films, 666, 76 (2018).2) N. Fukumuro, H. Yoshida, T. Yamazaki, Y. Fukai, and S. Yae, J. Japan. Inst. Met. Mater., 80, 736 (2016).3) Y. Fukai, M. Mizutani, S. Yokota, M. Kanazawa, Y. Miura, and T. Watanabe, J. Alloy. Comp., 356-357, 270 (2003).

A novel strategy to electrodeposit high-quality copper foils using composite additive and pulse superimposed on direct current

As a crucial material for fabrication of lithium-ion battery current collector, the properties of electrodeposited copper foil are closely related to the battery performances. How to improve its properties is thus of great importance for battery design and manufacturing. In this paper, we reported a novel composite additive, consisting of collagen, glycerol, hydroxyethyl cellulose, and sodium polydisulfide dipropane sulfonate, for electrodeposition of high-quality copper foil from conventional acid copper sulfate bath. Meanwhile, a pulse superimposed on direct current was used during the preparation process of copper foil. It was demonstrated that the additive could improve the foil’s performances, through changing the kinetic parameters of copper electrodeposition in sulfate bath. The optimized bath has a higher allowable current density during superimposed current electrodeposition, in contrast to the situation in direct current electrodeposition. This may then lead to an increase in deposition rate of copper foil, and a further improvement in surface roughness, grain size, residual stress, as well as elongation. Specially, the superimposed current offers a number of adjustable parameters for modulating copper foil’s properties in a wide range.

Electrodeposition of Cuprous Oxide on a Free-Standing Porous Cu Framework for Photoelectrochemical Water Splitting

The use of hydrogen as a chemical fuel is an attractive and promising method as an alternative sustainable green energy carrier. The combination of direct sunlight and semiconductor photoelectrodes in a photo-electrochemical (PEC) cell can generate hydrogen by splitting water molecules into H2 and O2 1. Copper(I) oxide or Cuprous oxide (Cu2O) is a p-type semiconductor with a bandgap of ~2 eV which makes it suitable for solar visible light absorption and it possesses a suitable band position for water reduction to hydrogen in the PEC cell2. The focus here is to increase the surface area of Cu2O photocathode to improve the PEC water splitting performance. Using dynamic hydrogen-bubble assisted electrochemical deposition method, a highly porous Cu substrate was synthesized in an acid copper sulfate bath at current densities above -1 A/cm2. To obtain a free-standing porous copper framework the structure must be reinforced at a lower current density using the same acidic bath and was separated from the substrate via ultrasonication The Cu2O crystal was then deposited on the free-standing porous Cu framework from an alkaline copper bath. The photoelectrochemical analysis of Cu2O was performed using a solar simulator at 1.5 AM and it shows a significant improvement of the photocurrent in comparison to the planar sample. M. Grätzel, Nature, 414, 338–344 (2001).A. Paracchino, V. Laporte, K. Sivula, M. Grätzel, and E. Thimsen, Nat. Mater., 10, 456–461 (2011). Figure 1

Electrodeposition of Zn-Ni Alloy from Alkaline Sulphate Bath Triethanolamine and Mercaptopyridine

Electrodeposition of Zn-Ni alloy from non-cyanide alkaline sulphate bath containing triethanolamine (TEA) and mercaptopyridine (MPY) under optimized plating conditions such as bath pH, temperature current density and metal ion ratio in the bath produced an alloy deposit with the desired composition of 10-15 %wt. of nickel, alloy of this composition showed good adhesion, high hardness pore free, smooth, uniform and finer grained. Deposition potentials of Zn-Ni alloy lie between the potentials of individual metals. Increase in temperature density decreased the nickel content in the alloy deposit, which with increase in temperature and thickness of the alloy deposit increased nickel content in the alloy deposit. Alloy deposition followed a regular type of co-deposition.

Physico-Chemical Properties of Zn-Ni Alloy Deposits from an Acid Sulphate Bath Containing Ethanolamines

The composition, properties, structure and morphology of electrodeposited Zn-Ni alloy deposits obtained from an acid sulphate bath have been investigated. A bath having higher percentage of nickel (50%) produced an alloy deposit with low percentage of nickel (12%), the percentage of nickel in the alloy deposit increases with current density up to 40 A.dm-2, with further increase in current density, the percentage of nickel shows a downward trend, increase in temperature of the plating bath increases the percentage of nickel in the alloy deposit. The hardness of the alloy deposits increases with increase in nickel content in the alloy, the phase structure of alloy deposit shows the presence of α, η, δ and γ phases. The morphology of Zn-Ni alloy deposits shows uniform and finer grained structure.

Part I: Ni-Co alloy foils electrodeposited using ionic liquids

The Ni-Co alloy co-electrodeposit from a sulfate bath including two new ionic liquids 1-methyl-3-(2-oxo-2-((2,4,5 trifluorophenyl) amino) ethyl)-1H-imidazol-3-ium iodide [MOFIM]I and 1-(4-fluorobenzyl)-3-(4-phenoxybutyl) imidazol-3-ium bromide [FPIM]Br as additives was characterized using the SEM, EDS, EDS mapping, XRD, AFM and microhardness measurement techniques. The resultant surface morphologies in acidic sulfate baths on a copper substrate demonstrated that both the [MOFIM]I and [FPIM]Br additives served as effective leveling agents. The Ni-Co alloy co-deposit morphology in the [MOFIM]I bath was more enhanced (non-grained coating, Ra of 28 nm and Rt of 35.5 nm) than that in the [FPIM]Br bath (grain size 225 nm, Ra of 51. 1 nm and Rt of 65.7 nm) owing to the molecular structure. The co-deposition of Co and Ni from the acidic baths was of the anomalous type. Moreover, the anomalous behavior of the Ni-Co co-deposition was alleviated after [MOFIM]I and [FPIM]Br were introduced in the bath. To determine the optimal bath conditions, the cathodic current efficiency (CCE%) value was calculated during the Ni-Co alloy co-electrodeposition process under three different compositions and different operating conditions. Under the composition of Ni 70% and Co 30% (Ni70%-Co30% alloy deposit), the CCE% values increased considerably, with maximum values of 99.8% and 97.07% in the baths including [MOFIM]I and [FPIM]Br, respectively.

Electrodeposition of Zn-Fe Alloy from Non-Cyanide Alkaline Sulphate Bath Containing Tartarate

Electrodeposition of Zn-Fe alloy from an alkaline sulphate bath containing tartarate has been carried out. The effect of plating variables on the composition of alloy and on cathodic current efficiency was studied. The cyclic voltammetric studies carried out to know the mutual co-deposition of zinc and iron. Hardness and the surface morphology of the alloy deposits were found to be dependent on the iron content in the alloy. An alloy containing 20% wt. Fe showed smooth, uniform and finer grained deposits. Under the optimum composition and operating conditions, Zn-Fe alloy deposition from alkaline sulphate bath containing tartarate followed anomalous depositing process.

Spa therapy and burn scar treatment: a systematic review of the literature.

Spa therapy is an integral part of the treatment of burn scars. The objective of this systematic review is to provide an overview of the spa therapy used in the treatment of burn scars and analyze its effects reported in clinical studies. We used the PRISMA checklist and queried 8 scientific databases from August 2019 to July 2020 for articles referenced with the specific key words: (burn) AND ((spa) OR (crenotherap*) OR (sulfur bath) OR (balneo*) OR (hydrotherap*) OR (mineral water) OR (thermal water) OR (spring water) OR (health resort medicine)). We used the EPHPP-QAT to assess the quality of the studies. Out of 10,050 publications identified in our database searches, 3 studies were selected: 2 clinical trials and 1 descriptive multicenter study that polled surgeons for their opinion on spa therapy for burn patients. All of the articles concluded that spa therapy is positive in burn scar recovery. No strong study on the effectiveness of spa therapy for burn scars care according to the EPHPP-QAT was identified. Spa therapy in the Saint Gervais spa center appears to be the only spa technique to have been evaluated for burn scar care. This review underscores the need to perform clinical studies to evaluate the effects and benefits of spa therapy for burn scars on patient's quality of life, and improve our understanding of the mechanisms of action of physiotherapy. Care programs should be harmonized in order to conduct multicenter studies.

Effect of Pre-treatment on Roughness and Hydrophobicity of Electro-Etched Steel with Improved Corrosion Resistance

A hydrophobic steel surface was created by a simple electro-etching technique using a cobalt sulfate bath. The effect of surface pre-treatment on the hydrophobicity and surface roughness was investigated. The wettability and roughness of the surface were determined by water contact angle (WCA) and atomic force microscopy (AFM), respectively. Accordingly, the sample abraded with 800 grit sandpaper followed by electro-etching process was selected as the optimum sample with the highest roughness and WCA (Sa = 28.4 nm, Ra = 35.4 nm, and WCA = 144 ± 1.6°, respectively). The morphology and cross-sectional images of the hydrophobic surface were investigated using field-emission scanning electron microscopy (FESEM). FESEM images showed a micro/nanostructured surface. The resulted hydrophobicity was attributed to the high roughness and overhanging structure obtained through this method. Furthermore, by using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests, the corrosion behavior of the samples was investigated. It was revealed that the surface hydrophobicity improved the corrosion resistance by increasing the polarization resistance (from 726 to 1598 Ω cm2) and decreasing the corrosion current density (from 0.025 to 0.012 mA cm−2). The simplicity of creating a hydrophobic surface with the improved corrosion behavior, the availability, and the low cost of the materials used to develop this approach makes it a proper candidate for large-scale and industrial applications.

STUDY OF Zn–Co ALLOY COATINGS MODIFIED BY NANO- TiO2 PARTICLES INCORPORATION

The purpose of this paper is to investigate the effect of TiO2 nanoparticles contents on structural properties, microhardness and corrosion resistance of Zn-Co alloy coating and ZnCo-TiO2 composite coatings is electrodeposited on steel substrate in the acid sulfate bath, The smaller grain size of the composite coatings is observed in the presence of TiO2 and it is confirmed by the images of scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The corrosion performance of coating in the 3 % NaCl as a corrosive solution is investigated by potentiodynamic polarization and electrochemical impedance spectroscopy EIS methods. It is found that the incorporation of nanoparticules in Zn–Co alloy coating have better corrosion resistance and the values of Rct and Zw increase, while the values of Cdl decrease with the increasing of nanoparticules

Zn–Ni compositionally modulated multilayered alloy coatings for improved corrosion resistance

ABSTRACT Zinc–Nickel monolayer (single layer) and compositionally modulated multilayer alloy coatings were developed on to mild steel from acidic sulphate bath; and their corrosion performance were studied using potentiodynamic polarization and electrochemical impedance spectroscopy methods. The coating layers were formed galvanostatically by single bath technique, using square current pulses and triangular current pulses. For the best efficiency of the deposits against corrosion, the switched cathode current density and the number of layers were optimized. Under optimized conditions, Zn–Ni multilayer alloy coatings were produced at the current density 3.0/5.0 A dm−2 having 300 layers were ∼65 (square) and ∼48 (triangular) times more corrosion resistant respectively than the single layer alloy coating of the same thickness. Scanning electron microscopy has been employed to investigate, the formation of multilayer alloy coatings as well as the morphology of the surface before and after corrosion studies.