Copper Sulfate Acid Research Articles

N, S-carbon quantum dots as inhibitor in pickling process of heat exchangers for enhanced performance in multi-stage flash seawater desalination

The heat exchanger in multi-stage flash seawater desalination needs to be pickled during long-term service to remove oxidation products on the copper surface. In this paper, we introduce a method for preparing carbon quantum dots from biowaste, and explore their ability to inhibit the corrosion of copper in sulfuric acid and its corrosion inhibition mechanism. Firstly, the UV–vis spectra, microstructure, tissue composition of N, S-CDs were tested by Ultraviolet-visible spectrophotometer, TEM and Fourier transform infrared. Secondly, the effectiveness of N, S-CDs in preventing corrosion was analyzed by electrochemical testing. The electrochemical test results showed that the impedance value of the solution of 200 mg/L N, S-CDs was 94,440 Ω cm2 at 298 K， with corrosion inhibition efficiencies (η) of 99.89 %, 99.77 % and 99.72 % at 298 K, 308 K, and 318 K, respectively. Moreover, SEM, XPS and AFM were used to characterize the micro-morphology and composition both before and after corrosion. It is worth noting that we used the fluorescence properties of carbon quantum dots as fluorescent probes to deeply verify the corrosion inhibition mechanism of N, S-CDs on copper.

Enhanced interface structure of electroformed copper/diamond composites for thermal management applications

Abstract As the power density of electronic devices increases, the requirement for heat sinks with enhanced thermal properties becomes imperative for advanced heat dissipation. Copper/diamond composites are next-generation heat dissipators with high thermal conductivities, yet fabrication of these composites requires high energy and complex instruments. In this study, copper/diamond composites are fabricated by electroforming. The sediment co-deposition process is modified to obtain uniform diamond particle distribution with tailorable volume fraction. Diamond particles were initially settled on the cathode surface outside the electrolyte, and then the setup was immersed in an acidic copper sulfate electroforming bath. Varying amounts (0–100 mg l−1) of thiourea are introduced to the electrolyte to enhance the matrix–particle interface. The gaps between diamond particles are filled with electrodeposited copper using optimized deposition conditions. The composite structure detaches from the cathode by itself after the production with desired shape and dimensions. The effect of operating conditions on cathodic polarization, composite microstructure, and thermal properties are investigated. Thermal conductivity of 49 vol.% diamond containing sample fabricated with optimized parameters exceeds 667 W m−1 K−1. The increase in thermal conductivity and enhanced interface structure is attributed to the excellent void-filling ability of the optimized electrolyte.

Evaluation of Adhesion for Better Electrodeposited Cu Foil on Titanium Substrate

Titanium metal is known to have good corrosion resistance. For the plating of Cu in many industrial applications, Ti metal is commonly used as the cathode for the reduction of Cu. Under an acidic and high temperature environment, the passivation layer on the surface of the titanium metal tends to react with acidic solution. As a result, the corrosion of the active titanium metal was observed. In this study, the corrosion behavior of commercial pure titanium in acid copper sulfate baths was investigated, and several surface treatments were used to improve the corrosion resistance of titanium passive layer. The microstructure of titanium metal after immersion in acid copper sulfate solution was examined by using SEM and FIB. The pitting corrosion of Ti was clearly observed using SEM. The corrosion mechanism of the titanium metal in the sulfuric acid solution was discussed. In addition, the electrochemical characteristics of commercial pure titanium metal in sulfuric acid solution were also analyzed using the three-pole potential measurement method.

Ionic Copolymers Including Iodide and Dihydrogen Phosphate Anions for Increased Adsorption and Anticorrosion on Copper in Sulfuric Acid

Ionic Copolymers Including Iodide and Dihydrogen Phosphate Anions for Increased Adsorption and Anticorrosion on Copper in Sulfuric Acid

Investigation of poly (2-methyl imidazole co 1,4-butanediol diglycidyl ether) as a leveler for blind hole copper plating

<p>The current synthetic leveler agents are complex to operate, troublesome to purify, and low to pore filling rates. Herein, we report a new, simple, green, and inexpensive method for the synthesis of leveler agents and study their properties systematically. In acidic copper sulfate plating solutions, including polyethylene glycol (PEG), sodium 3,3’-dithiodipropane sulfonate (SPS), and chloride ions, the relation between leveler agents (dimethylimidazole and 1,4-butanediol diglycidyl ether) and the filling of blind holes have been investigated. The synthesized leveler agent was structurally characterized by infrared spectroscopy and gel chromatography tests. The plating containing the leveler agent passed plating tests as well as reliability tests and met PCB production requirements. The electrochemical behavior of the leveler agent was investigated using electrochemical tests. The X-ray diffractometer (XRD) was used to observe the differences in crystal orientation on the surface of the plated layers.<strong></strong></p>

Effect of Ti Corrostion on Separation of Electro-Deposited Cu Foil

Cu foils by electroplating are known for many industrial applications such as PCB and Li ion batteries. Ti metal is commonly used as the cathode for the Cu reduction from sulfate solution. Under an acidic and high temperature environment, the passivation layer on the surface of the titanium metal tends to react with acidic solution. As a result, the corrosion of the active titanium metal was observed. In this study, the corrosion behavior of commercial pure titanium in acid copper sulfate baths was investigated, and several surface treatments were used to improve the corrosion resistance of titanium passive layer. The microstructure of titanium metal after immersion in acid copper sulfate solution was examined by using SEM and FIB. The pitting corrosion of Ti was clearly observed using SEM. The corrosion mechanism of the titanium metal in the sulfuric acid solution was discussed. In addition, the electrochemical characteristics of commercial pure titanium metal in sulfuric acid solution were also analyzed using the three-pole potential measurement method.

The behavior of two indazole derivatives on the copper/sulfuric acid interface in terms of adsorption and corrosion inhibition

BackgroundTo reduce the degree of copper corrosion by the pickling solution, the introduction of organic inhibitors into the pickling solution is a reasonably effective measure.5-fluoro-1H-indazole (5-FIA) and 5‑chloro-1H-indazole (5-CIA) may act as exceptional inhibitors. MethodsBased on experimental and theoretical methods, the antiseptic ability of two indazole derivatives on copper in sulfuric acid was researched. Significant findsThe results of electrochemical experiments show that in the test solution containing 1 mM inhibitors, the corrosion inhibition efficiency (η) of 5-FIA and 5-CIA was 90.4% and 94.3%, respectively, indicating that 5-FIA and 5-CIA have outstanding corrosion inhibition capabilities and their antiseptic effects are in the order of 5-FIA < 5-CIA, which is also confirmed by observations of Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Furthermore, both 5-FIA and 5-CIA are mixed-type inhibitors and their adsorption behavior follows Langmuir isothermal adsorption model. The results of X-ray Photoelectron Spectroscopy (XPS), theoretical calculations, and molecular dynamics simulations further reveal the mechanism that 5-CIA has stronger adsorption capacity than 5-FIA.

(Digital Presentation) Corrosion-Resistance Investigation of Titanium Passive Layer in Acidic Solution

Titanium metal is known to have good corrosion resistance. For the plating of Cu in many industrial applications, Ti metal is commonly used as the cathode for the reduction of Cu. Under an acidic and high temperature environment, the passivation layer on the surface of the titanium metal tends to react with acidic solution. As a result, the corrosion of the active titanium metal was observed. In this study, the corrosion behavior of commercial pure titanium in acid copper sulfate baths was investigated, and several surface treatments were used to improve the corrosion resistance of titanium passive layer. The microstructure of titanium metal after immersion in acid copper sulfate solution was examined by using SEM and FIB. The pitting corrosion of Ti was clearly observed using SEM. The corrosion mechanism of the titanium metal in the sulfuric acid solution was discussed. In addition, the electrochemical characteristics of commercial pure titanium metal in sulfuric acid solution were also analyzed using the three-pole potential measurement method.

(Invited) In-Situ Observation of Copper Electroplating with Additives Using Micofluidic Devices

Recent advances in integrated circuit have been driven by packaging technology. 3D packaging using TSV (Through-Silicon Via) is becoming common in commercial products. TSVs are formed by filling deep holes with a conductive material. Copper is widely used as the conductive material, since filling the deep holes with copper is enabled by bottom-up electrodeposition using a combination of several additives. Suppressors, levelers, and accelerators are well known categories of additive to acid copper sulfate plating solutions. Bottom-up deposition is realized by various additive formulas. Using leveler alone as additive, extreme bottom-up filling has been demonstrated, and levelers are considered to be essential for bottom-up deposition. But the mechanism is not yet clear with multiple additives addition.Therefore, understanding of additive behaviors is important. Cyclic voltammetry using a rotational disk electrode has been widely used in additive studies, but interpretation of the results is not easy because adsorption occurs simultaneously with deactivation. The history of additive supply onto the plating surface also influences the hysteretic behavior. Recently, we constructed a microfluidic device in which flow cell experiments and rapid switching of the plating solution are enabled. Using the device, characteristic behavior of leveler, strong suppression and rapid deactivation, was directly observed optical microscopically and electrochemically, and difference with levelers and suppressors was clarified. Further, a TSV-like structure with similar dimensions to real TSVs was constructed in a microchannel, and real-time optical observation of bottom-up deposition was demonstrated.References T. Akita, et al., J. Electrochem. Soc., 166(1), D3058 (2019)M. Tomie, et al., J. Electrochem. Soc., 167, 082513 (2020)T. Akita, Y. Otsuka, M. Hayase, J. Electrochem. Soc., 167, 162515 (2020)

Corrosion inhibition of copper in sulfuric acid by Leonurus japonicus Houtt. extract as a green corrosion inhibitor: Combination of experimental and theoretical research

BackgroundBased on the consideration of green and safety in industrial production, the demand and desire for green corrosion inhibitors are increasingly strong. MethodsIn this study, we selected Leonurus japonicus Houtt. leaves extract (LLE) extracted by water. Electrochemistry experiments and morphology characterization showed excellent anti-corrosion performance of LLE for copper in 0.5 mol∙L1 H2SO4. The chemical bond information measured by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) indicated that LLE adsorbed on Cu/H2SO4 interface by chemical bonding. Through quantum chemical calculation and molecular dynamics simulation analysis, the adsorption reaction mechanism was profoundly studied. Significant findsElectrochemical test data showed that the inhibition efficiency of 400mg/L LLE arrived at 90% at 298 K, 308K and 318 K. After processing the data, it is concluded that LLE protective film belonged to Langmuir adsorption. By calculating thermodynamic and kinetic parameters of corrosion, it is found that the activation complex is formed by the binding of Cu+ and LLE in the adsorption layer.

Promotion of High-Speed Copper-Filling Performance for Interconnections with Increasing Aspect-Ratio Using Compound Additives.

Interconnections are essential for integrating the packaging substrate, and defect-free copper-filling can further improve the reliability in through holes (THs). The coating properties and filling processes are mainly dominated by the interplays among additives in the direct current electroplating. The acidic copper sulfate electroplating solution contained three typical convection-dependent additives and chloride ions (Cl−). The THs with aspect ratios (ARs) of 6.25, 5, and 4.17 (thickness of 500 μm) were selected as the study subjects. The effects of Cl− and ARs on the interactions among the additives were investigated in detail using electrochemical measurements, which were verified by the THs filling experiments. The additive compounds present a convection enhanced inhibition effect and cathodic polarization, leading to a copper filling capacity increase with ARs and the amelioration of copper compactness and corrosion resistance. The defect-free copper filling of THs and a uniform mirror bright surface circuit can be achieved simultaneously using compound additives at a relatively high speed.

(Digital Presentation) Anti-Corrosion Investigation of Titanium Electrode for Cu Plating

For the plating of Cu in many industrial applications, Ti metal is commonly used as the cathode for the reduction of Cu. Titanium metal is known to exhibit adequate corrosion resistance due to the formation of a thin passivation layer on the surface. Under an acidic and high temperature environment, the passivation layer on the surface of the titanium metal tends to react with acidic solution. In other words, Ti metal tends to be corroded in an acidic environment. The corrosion behavior of commercial pure titanium in acid copper sulfate baths was investigated in this study. Available surface treatments were applied to suppress the corrosion of titanium passive layer. The microstructure of titanium metal after immersion in acid copper sulfate solution was examined by using SEM and FIB. The pitted and corroded Ti was clearly observed using SEM. The corrosion mechanism of the titanium metal in the sulfuric acid solution was discussed. In addition, the electrochemical characteristics of commercial pure titanium metal in sulfuric acid solution were also analyzed using the three-pole potential measurement method.

Thick Copper Layer Growth By Dynamic Hydrogen Bubble Template Using Continuous and Pulse Currents

Copper is the most widely used materials for microelectronics applications due to their electrical and thermal conduction properties, and in several appplications, thick and porous layers are requested.Different possibilities still exists such as copper-zinc or copper-manganese electrodeposition followed by an anodic dissolution, but the faster and simpler way resides in electroforming deposition made by Dynamic Hydrogen Bubble Template (DHBT) [1]. This process works in unusual potentials and current densities where the competition between hydrogen discharge (commonly avoided) and copper reduction is very high. In this case, this method achieves thick deposits in very short time (few seconds) with high currents allowing a very fast growth of copper around hydrogen bubbles. Pores and ligaments sizes can be controlled by several operating parameters i.e. current densities, temperature, deposit time as well as by chemical additives [2].With the use of a copper sulphate acid bath at various concentrations, with or without additives (acetic or hydrochloric acids) and by applying current densities between 100 and 400 A.dm-2, it is possible to obtain thick and porous coatings, with pores diameters between 10 and 500 µm and ligaments length between 10 and 200 µm. An example of a SEM image shows the morphology of the deposits obtained in top view and in cross section (Figure 1). Another possibility to control the 3D growth resides in the use of pulsed currents, with an effect on bubbles size. Furthermore, reverse pulses are useful for edge effects limitation.[1] Abdel-Karim, R.; El-Raghy, S. Chap 4 in Advanced materials and their applications - micro to nano scale. One Central Press, United Kingdom, pp 69–91, 2017[2] Shin, H.-C.; Liu, M. Chem. Mater. 2004, 16, 25, 5460–5464 doi.org/10.1021/cm048887bFigure 1 : SEM images of a) top view and b) cross section of a DHBT copper deposit Figure 1

Investigation of Cu-graphite composites prepared by electroforming

Abstract In this work, Cu-graphite composites were prepared by electroforming technology in an acidic copper sulfate bath with graphite particles in suspension. The factors affecting the codeposition of graphite particles with copper were studied. At a particle concentration of 20 g l –1, a current density of 3 A dm– 2 and a stirring rate of 100 min–1 graphite content in the composites was 21.7 vol.%.Microhardness and friction coefficient of the composites decreased with increasing graphite content. However, wear mass-loss decreased, but increased with graphite content above 21.7 vol.%. The wear mechanisms of pure Cu and Cu-graphite composites were adhesive wear and delaminating wear, respectively.

Electrochemical codeposition of arsenic from acidic copper sulfate baths: The implications for sustainable copper electrometallurgy

• The main source of arsenic contamination is codeposition during the nucleation stage. • Convection and concentrated Cu(II) electrolytes mitigate arsenic contamination. • The reduction of As(III) to metallic As does not occur readily. • Fast removal of As(III) possible by copper-arsenic codeposition. Copper producers face increased demand associated with increasing complexity in feedstock composition, including high amounts of impurity metals. In this work, linear sweep voltammetry was used to study the electrodeposition behavior of copper and arsenic, define strategies for the production of grade A copper, and the removal of arsenic from complex electrolytes. Our results show that the copper concentration is a key parameter to control in the electrodeposition process. The continuous deposition of arsenic from the electrolyte requires copper in solution (≤10 g L −1 Cu(II) for 2 g L −1 As(III)) to form copper arsenides . The deposition of metallic arsenic does not occur readily. Conversely, the use of a concentrated Cu(II) solution (e.g. 40 g L −1 ) resulted in grade A copper from an electrolyte with a maximum of 2 g L −1 As(III) under galvanostatic control at a current density of – 42 mA cm −2 . Time-of-Flight Secondary Ion Mass Spectrometry depth profile measurements on copper deposits revealed that arsenic contamination was entirely concentrated near the substrate side of the deposit and progressively decreased further into the deposit. The codeposition of arsenic occurred along with the initial copper nucleation, when the electrochemical potential for electrodepostion under galvanostatic control is temporarily lower. These findings provide important insights for future sustainable copper electrodeposition technologies from complex feedstocks.

Corrosion inhibition of copper in sulfuric acid via environmentally friendly inhibitor (Myrtus Communis): Combining experimental and theoretical methods

The essential oil of Myrtus Communis (MyC) from the region of Chefchaouen (northeastern Morocco) analyzed by gas chromatography coupled with mass spectrometry (GC/MS) is mainly composed of I, 8-cineole (35.6%), myrtenyl acetate (32.7%), and ⍺-pinene (8.9%). The inhibitory effect of this oil studied on the corrosion of Copper in a solution of H2SO4 0.5 M, shows a mixed type behavior. We were able to show that the essential oil of Myrtus Communis inhibits the corrosion of Copper in the tested solution with a significant efficiency which increases with the oil concentration to reach a maximum of 93.5% at a concentration of 2 g/l. The submerged surface of copper has been identified by Scanning Electron Microscopy coupled with Energy dispersive X-ray analysis (SEM/EDS), Atomic Force Microscopy (AFM) spectroscopy and Contact angle measurements (θ). The experimental studies Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP) were completed by the theoretical studies (Density Functional Theory (DFT) calculations and monte carlo (MC) simulations). Experimental data showed that the inhibitor Myc is effective against the corrosion acid of copper.

Porous Copper Electroforming By Dynamic Hydrogen Bubble Template Using Continuous and Pulse Currents

Copper is the most widely used materials for microelectronics applications due to their electrical and thermal conduction properties. In power electronics converters, it plays several roles and is the main constituent of cooling systems, but is also used for joints to be thermocompressed directly on power semi-conductor device. The possibility to get a 3D patterns of porous copper electroformed “in-situ” on the metallized ceramic substrate is an attractive development area which constitute a task in the COPPERPACK project (ANR-19-CE05-0011-04).Different possibilities still exists such as copper-zinc or copper-manganese electrodeposition followed by an anodic dissolution, but the faster and simpler way resides in electroforming deposition made by Dynamic Hydrogen Bubble Template (DHBT) [1]. This process works in unusual potentials and current densities where the competition between hydrogen discharge (commonly avoided) and copper reduction is very high. In this case, this method achieves thick deposits in very short time (few seconds) with high currents allowing a very fast growth of copper around hydrogen bubbles. Pores and ligaments sizes can be controlled by several operating parameters i.e. current densities, temperature, deposit time as well as by chemical additives [2].With the use of a copper sulphate acid bath at various concentrations, with or without additives (acetic or hydrochloric acids) and by applying current densities between 100 and 400 A.dm-2, it is possible to obtain thick and porous coatings, with pores diameters between 10 and 500 µm and ligaments length between 10 and 200 µm. An example of a SEM image shows the morphology of the deposits obtained in top view and in cross section (Figure 1). Another possibility to control the 3D growth resides in the use of pulsed currents, with an effect on bubbles size. Furthermore, reverse pulses are useful for edge effects limitation.[1] Abdel-Karim, R.; El-Raghy, S. Chap 4 in Advanced materials and their applications - micro to nano scale. One Central Press, United Kingdom, pp 69–91, 2017[2] Shin, H.-C.; Liu, M. Chem. Mater. 2004, 16, 25, 5460–5464 doi.org/10.1021/cm048887b Figure 1

Computed tomography assessment of soil and sediment porosity modifications from exposure to an acid copper sulfate solution

Mine spills, like acidified copper sulfate solutions, are known for the contaminating effects in soils and sediments, chemically altering them. However, little is known about the physical effects of this process. Therefore, we investigated the response of the soil and sediments porosity to the infiltration of an acid copper sulfate solution (ACSS) generated for mining purposes. The samples used consisted of intact/undisturbed soil and sediment columns extracted in the upper Rio Sonora basin, located in northern Mexico in the state of Sonora, where extensive mining activity has been carried out since 1880's. Three infiltration and solute transport experiments were conducted to monitor the changes in pH, electrical conductivity (EC) and flow velocity in the collected leachate. Computed X-Ray Tomography was used to microscopically analyze a series of soil porosity images before and after each irrigation with ACSS. We observed that the interactions of soil/sediment matrices with ACSS, promoted changes in the flow velocity, which can be related to the modification of the original porosity. The computed X-Ray Tomography showed that the passage of the ACSS through the soil and sediment caused different effects in both matrices: (1) a decrease in the number and size of pores in the soil column and (2) an increase in the number and size of pores in the sediment, showing that the passage of the solution in both matrices had opposite effects, causing a decrease in soil porosity as a possible response to the presence of suspended particles related to the ACSS, and the formation of new minerals that caused the sealing of pores in the soil and the erosion of the walls of the pores in the sediment creating preferential flows. This work shows that soils and sediments that interact with the ACSS are not only affected chemically, but also that there may appear modifications in porosity, leading to study also the physical effects that occur in sites affected by this type of events.

Investigation on the corrosion resistance of the CuO-Al2O3 composite coating prepared by micro-arc oxidation

A CuO-Al2O3 composite coating was obtained by an AC deposition and a followed secondary MAO treatment in an acidic copper sulfate electrolyte and an alkaline sodium hexametaphosphate electrolyte. Analyzes on phase and elemental composition and microstructure showed that a continuous CuO layer was formed on the top of the original MAO coating. EIS test suggested that after a secondary MAO treatment for 1 min, the samples obtained by AC deposition for 5 min had the best corrosion resistance, because of the barrier of CuO layer to the NaCl solution.

Long-Term Electrodeposition under a Uniform Parallel Magnetic Field. 1. Instability of Two-Dimensional Nucleation in an Electric Double Layer.

Under a parallel magnetic field, after long-term copper deposition from an acidic copper sulfate solution, numerous spherical secondary nodules of 10 to 100 μm diameters were formed one upon another in dendritic mode. This is a new type of micro-magnetohydrodynamic (MHD) effect arising from the unstable growth of three-dimensional (3D) and two-dimensional (2D) nuclei by specific adsorption of hydrogen ions (second micro-MHD effect). From the viewpoint of instability in electrodeposition, though 3D nucleation in the diffusion layer is always unstable, with ionic specific adsorption such as hydrogen ions, stable 2D nucleation turns unstable after long-term deposition. The resultant competitive growth of 3D and 2D nuclei produces spherical nodules as their composite, leading to their dendritic growth. Furthermore, though negligibly small, nonequilibrium fluctuations occurring in 2D nucleation migrate with the laminar solution flow caused by Lorentz force (MHD flow). Depending on whether the ionic adsorption is specific or nonspecific, the traveling asymmetrical fluctuation changes the direction to the upstream or downstream side, respectively.