Nickel Plating Research Articles

Analysis of the Effect of Time on Tensile Strength and Hardness of Electroplating Method Using Nickel on Aluminum 7075

The purpose of this research of aluminum electroplating with nickel is to improve the value of its tensile strength and hardness. This test was conducted to determine the effect of time towards the tensile strength and hardness of nickel on aluminum 7075 electroplating and the time required to achieve optimum conditions. The materials used in this study are aluminum 7075 and nickel plating. The finishing treatment process used was electroplating method. Fixed variables utilized in this study comprised the voltage (25 V), gap between electrodes (15 cm), amount of water (2400 ml), salt (four spoons), vinegar (1600 ml), aluminum, and nickel for plating. The variations used in immersion time were 30, 40, and 60 minutes for further tensile test and hardness test. The result of this research shows that the highest tensile strength value obtained was 546,155 MPa with 60 minutes coating time. While the value of hardness from time to time varied with the highest rate in of 30-minute coating time was 188.266 kgf/mm. According to the test results, it can be inferred that the longer coating time it takes, the higher the tensile strength rate the material obtains.

Microstructure and Properties of Hollow Octet Nickel Lattice Materials.

In this study, electroless nickel plating and electrodeposition were used to deposit thin films on the polymer lattice template prepared by 3D printing, then seven Octet hollow nickel lattice materials with different structural parameters were synthesized by etching process at the expense of the polymer backbone. The microstructure and properties of the Octet structure nickel lattice were characterized by X-ray diffraction, Electron backscattering diffraction and transmission electron microscopy. According to the results, the average grain size of the electrodeposition Ni lattice material was 429 nm, and (001) weak texture was found along the direction of the film deposition. The lattice deformation mode changed with the increase of the lattice length-to-diameter ratio, and it shifted from the lattice deformation layer-by-layer and the overall deformation to the shear deformation in the 45° direction. The strength, modulus and energy absorption properties of the Octet lattice increased with the density, and they were exponentially related to density. In the relative density range of 0.7~5%, Octet hollow Ni lattices with the same density conditions but different structural parameters showed similar compressive strength and elasticity modulus; the energy absorption capacity, however, was weakened as the length-to-diameter ratio increased.

Drilling fluid adhesion resistance of electroless plating nickel phosphorus (Ni-P) alloy coating deposited on laser-textured surface of bit waterways

The drilling ball phenomenon on polycrystalline diamond compact(PDC) bit seriously restricts the exploitation of oil and gas fields. Wear-resistant Ni-P alloy coating and surface hydrophobic texture are used to solve the problem of ball drilling. Ni-P alloy coating deposited on 42CrMo laser-textured (rectangular, linear and sinusoidal) surface by electroless plating. In the wettability of water-based drilling fluid, the rectangular texture coating with a spacing of 150–200 µm has a maximum contact angle of 133.7°, which is 75.69 % higher than the 42CrMo steel. the anti-mud adhesion and erosion life has also been improved to a certain extent. This research provides important experimental results and theoretical basis for solving the ball drilling problem of PDC bits.

Preliminary Studies on the Electrochemical Conversion of Liquefied Forest Biomass

Bio-oils produced from three different biomass sources, namely cork, pinewood, and olive stones, are evaluated concerning their suitability and prospects of including their electrochemical transformations in a biorefinery scenario for the production of added-value compounds. Different types and concentrations of electrolytes (e.g., H2SO4, KOH) are added to the bio-oils to increase the samples’ initially low ionic conductivity. The samples prepared by mixing bio-oil with 2 M KOH aqueous solution (50 vol.%) lead to a stable and homogeneous bio-oil alkaline emulsion suitable for electrochemical studies. The bio-oil samples are characterized by physicochemical methods (e.g., density, viscosity, conductivity), followed by analyzing their electrochemical behavior by voltammetric and chronoamperometric studies. The organics electrooxidation and the hydrogen evolution reaction in the bio-oils are assessed using Pt electrodes. Single- and two-compartment cell laboratory bio-oil electrolyzers are assembled using nickel plate electrodes. Electrolysis is carried out at 2.5 V for 24 h. Attenuated Total Reflection-Fourier-Transform Infrared Spectroscopy and Mass Spectrometry are applied to identify possible changes in the bio-oil samples’ chemical structure during the electrolysis experiments. Comparing the analyses of the bio-oil samples subjected to electrolysis with the blank samples demonstrates that bulk electrolysis significantly changes the bio-oil composition. The bio-oil obtained from cork biomass shows the most promising results, but further studies are required to understand the nature of the actual changes.

Activation of nickel foam, as a current collector of a supercapacitor, by impact nickel plating: influence of treatment conditions

Nickel foam is widely used as a current lead/current collector and as the base of nickel hydroxide electrodes for hybrid supercapacitors. An investigation of the influence of activation conditions for a commercial sample of nickel foam produced by Linyi Gelon LIB Co Ltd (China) was carried out using the method of impact nickel plating. The morphology of activated and non-activated nickel foam samples was investigated by scanning electron microscopy. Activated and non-activated nickel foam samples were investigated by methods of cyclic voltammetry and galvanostatic charge-discharge cycling in the supercapacitor mode. It was shown that upon activation at i=1 A/dm2 and τ=10 min, a thin layer of porous nickel with incomplete coverage was formed. Activation with impact nickel at i=7 A/dm2 and τ=3 min revealed the formation of a nickel coating with a highly developed surface, on which local cracks were found as a result of the accumulation of internal stresses. Activation with impact nickel at i=1 A/dm2 and τ=10 min led to the formation of a coating with a highly developed surface, with significant peeling of the coating. Cyclic voltammetry showed high efficiency of impact nickel activation at i=7 A/dm2, τ=3 min, and i=20 A/dm2, τ=5 min. The specific current of the cathode peak increased 6.06–6.44 times with respect to the non-activated sample. The investigation of the activated samples' electrochemical characteristics by the galvanostatic cycling method showed that impact nickel activation at i=1 A/dm2 and τ=10 min was insufficient. It was found that at a discharge up to E=0 V, the maximum specific capacitance of 0.731 F/cm2 was obtained for samples activated by impact nickel at i=7 A/dm2 and τ=3 min. The increase in specific capacitance compared to the non-activated sample was 4.49 times. At full discharge, the highest electrochemical activity was found for nickel foam samples activated by impact nickel at i=20 A/dm2 and τ=5 min. The specific capacitance was 0.505 mA∙h/cm2, and it increased 9.02 times

The Mg2NiH4 film on nickel substrate: synthesis, properties and kinetics of formation

We studied the synthesis reaction of Mg2NiH4 hydride films when a nickel plate and magnesium hydride powder interacted in the presence of hydrogen at 450 °C. The hydrogen pressure (>6 MPa) was higher than the synthesis equilibrium pressure for both Mg2NiH4 and MgH2 hydrides.Film examination with scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and thermal desorption spectroscopy methods revealed that a dense polycrystalline film of Mg2NiH4 hydride grows on a thin (0.9 μm) underlayer of intermetallic alloy MgNi2. The synthesis time variation made it possible to create Mg2NiH4 films with a width of 0.2 to 4 μm. Based on analysis of the growth kinetics, the crystal structure of the material, and energies of chemical bonds between atoms, we show that the interface between MgNi2 and Mg2NiH4 is the most probable location of the growth reaction.We have obtained cathode luminescence spectra of the Mg2NiH4 hydride film. Mg2NiH4 is found to be an indirect gap semiconductor with a gap value of ∼1.6 eV. However, luminescence with quanta energy higher than the band gap is registered. We associate this fact with Van Hove singularities in the Mg2NiH4 density of states.

Effect of Nanodiamond Content in the Plating Solution on the Corrosion Resistance of Nickel–Nanodiamond Composite Coatings Prepared on Annealed 45 Carbon Steel

A nickel-nanodiamond composite coating was prepared on the surface of annealed 45 carbon steel by double-pulse electrodeposition. The effect of nanodiamond particle content on the surface morphology, grain size and wear and corrosion resistance of the composite coating were investigated. According to the analysis of the test results of X-ray diffractometry and scanning electron microscopy, it was found that the cathodic polarization of the electrodeposition process was enhanced after the addition of nanodiamond particles to the Watts nickel plating solution. The positively charged nanodiamond particles on the surface facilitate the reduction reaction at the cathode. Nanodiamond particles provide crystalline growth sites for the non-spontaneous nucleation of nickel atoms. As the addition of nanodiamond particles increases, the diffusely distributed nanodiamond particles are able to attract more nickel ions to deposit nuclei, and its fine crystallization effect increases, resulting in improved wear resistance and corrosion resistance of the composite plating. Among the results, the polarization potential was the smallest when the nanodiamond content in the plating solution was 10 g/L. The surface of the prepared nickel-nanodiamond composite coating was relatively flat and smooth, with good density and a uniform grain size distribution, and the content of element C on the surface of the composite coating was the largest, reaching 1.99%.

Electroless Nickel Plating for Ohmic Contacts to Silicon Power Devices

Silicon diodes, FETs, IGBTs still keep the majority of power device market, being much cheaper compared to SiC and GaN wide band gap-based devices. To keep the Si devices competitive, their manufacturing processes must be significantly improved. This includes forming Ohmic contacts. Currently the common process is PVD – physical vapor deposition of metal stacks. This process is not efficient: not selective and wasteful - metal sputtered or evaporated from target coats entire vacuum chamber, not just wafer being processed.Electroless deposition can be potentially used for metallization of Si power devices. The electroless process can be designed selective, so the metal deposits only on silicon surface, not on areas protected by dielectric films. The deposited layer must have good adhesion to silicon surface, make Ohmic contact, and preferably converts into silicide upon anneal. Nickel satisfies all these requirements, thus is a good candidate. A major issue in Nickel plating on Si is that it does not deposits well onto very smooth polished surface of Si. Several approaches are known how to overcome this issue. Dubin [1] suggested adding pretreatment with Palladium. The Pd reacts autocatalytically on silicon surface forming Pd islands. Upon switching to Ni bath, Ni deposits on Pd first, then forms a continuous film when the islands merge.One issue in the Pd/Ni process are that the native oxide on silicon must be removed so Pd can reach Si. In Dubin’ process this is resolved by adding HF to Pd bath. Another issue is bad process repeatability – a consequence of autocatalytic nature of the Pd plating reaction. The autocatalytic processes have uncontrollable “incubation” time, therefore repeating Pd plating with same recipe (same time) does not produce the same results.We describe a new approach as to plate Nickel directly on polished Silicon surface. In our process the Pd activation of Si surface is replaced by a stain etch process. The stain etch is a process where crystalline Silicon is converted into porous Si layer [2]. Technically the stain etch is simply processing in a wet bath – mixture of concentrated nitric and hydrofluoric acids in a ratio around 1:1000. Same as in the Pd/Ni case, the process must be designed to exclude native Si oxide. We achieve this by direct switching from the stain bath to Ni bath, no water rinsing in between. The surface of wafer retrieved from the stain bath is highly hydrophobic (hydrogen terminated) thus there is no liquid drops on surface. A brief nitrogen gun drying is still performed, thus preventing contamination of Ni bath with HF. The hydrogen termination protects the surface. We tried both traditional Ni plating recipes – alkaline, and acidic [3], and found that Ni plating is good in both cases.However, the resulting Ni layer is heavily non-uniform in thickness. We observe that the Ni pattern repeats the visual pattern after the stain etch. A byproduct of the stain etch reaction is hydrogen. The hydrogen forms bubbles that stick to Si surface and cause local masking, eventually non-uniformity. Thus, the key to Ni plating uniformity is the uniform stain etch. Known approaches [2] - adding surfactants to the bath, etc. happen to be only partially efficient. Therefore, we tried new stain etch recipe: add glacial acetic acid thus getting HNA mixture 1000:1:1000. The hydrogen bubbles in the old recipe were about 2 mm in diameter and kept on Si surface for many seconds. In our recipe, the bubbles get released from Si surface as soon as they reach about 0.1 mm size. The eventual Si porous layer shows uniform color appearance across entire wafers.Notice, etching in the nitric/hydrofluoric mixture is also autocatalytic process, thus the topic of repeatability arises too. However, we use Si surface color change as the signal to finish the stain etch. Thus, we can get the same thickness porous film every time despite the incubation time varies uncontrollably.Direct Ni plating onto blanket polished Silicon wafers with the HNA 1000:1:1000 pretreatment shows uniform mirror like appearance. Very high surface area of the porous Si enables the Ni plating. Nano scale sizes of porous Si with plated Ni result in uniform silicide upon anneal.References Dubin, V.M., "Selective electroless Ni deposition onto Pd-activated Si for integrated circuit fabrication" Thin Solid Films 226,no.1(1993):94-98.Kolasinski, K.W. "Porous Si formation by galvanic etching." Handbook of Porous Silicon2 (2014).Delaunois, F. Electroless nickel plating: fundamentals to applications. CRC Press, 2019.

Improve the Zinc Slurry-Air Battery Performance: New Operational Mode to Separate Effects

In recent years, zinc air batteries received substantial interest as a viable next generation of batteries based on their merits of high energy densities, high performance, environmentally friendly, inexpensive, and abundant electrode material. Traditional secondary zinc air flow batteries use zinc metal as an anode. Severe dendrite growth and passivation limits the cycling behavior, which hinders commercialization in the industry. By substituting the zinc plate with a zinc slurry (zinc particles suspended in the alkaline media, typically with a high concentration of potassium hydroxide), the battery can in principle achieve higher energy density and attain more cycles but with very limited performance. Important questions related to such systems include the accessible percentage of Zn capacity, controlled by the formation of passivating layers on the particle and the intrinsic resistance of the slurry.Here, we present a new operational mode to investigate the performance of zinc slurry air battery. The anode of the test battery system consists of 5 cm2 nickel plate as current collector for 5 cm3 zinc slurry. The cathode consists of air electrode, bipolar plate, and current collector. Zinc particles (Spectrum) were suspended in 4M KOH stabilized by polyacrylic acid (PAA). In our testing, the polarization loss was measured and is separated from that associated with the air electrode using a reference electrode. The conductivity of the slurry was measured by the simply modified configuration of the cell. The utilization of zinc is measured by chronopotentiometry. The battery can work at 1.1 V with 200mA/cm2, and the slurry can achieve 48.7% utilization. Acknowledgements The authors gratefully acknowledge the support of the US Department of Energy Office of Electricity Storage Systems Program directed by Dr. Imre Gyuk and the University of Tennessee Governor’s Chair Fund for support of this work. Figure 1

(Digital Presentation) A Design of Nickel/Sulfur Energy-Storage Materials for Electrochemical Lithium-Sulfur Cells

Introduction As one of the next-generation rechargeable battery technologies beyond the lithium-ion chemistry, the lithium-sulfur chemistry enables the low-cost sulfur cathode to generate a high theoretical capacity of 1,675 mAh g-1 (10 times higher capacity than those of lithium-ion battery cathode). It further exhibits a high theoretical energy density of 2,600 Wh kg-1 in lithium-sulfur batteries (2–3 times higher energy density than lithium-ion batteries). However, as reported in recent publications, the development is far from adequate with respect to the high-loading sulfur cathode with high active-material content in building advanced lithium-sulfur batteries with a high energy density. The material challenges result from the use of an insulating sulfur as the active material, which would generate lithium polysulfides that can easily diffuse out from the cathode. The high cathode resistance and fast loss of the active material lead to the poor electrochemical utilization and efficiency of lithium-sulfur battery cathodes. These negative impacts subsequent derive the additional electrochemical challenges. A high amount of conductive and porous substrates is added in the cathode to replace the active material, which results in the limited amount of sulfur in the cathode and further blocks the improvement of designing high-energy-density sulfur cathodes.To address the above-mentioned issues, the research progresses of high-performance sulfur cathodes aim to design functional host for sulfur cathodes with the use of carbon for high conductivity, polymers for high ionic transfer, porous materials for physical polysulfide retention, polar materials for chemical polysulfide adsorption, catalysts for high reaction kinetics, etc. However, metallic materials that naturally have high conductivity, strong polysulfide adsorption capability, and catalytic conversion ability, are rarely reported. This is because metals have the highest density as compared to the aforementioned host materials, which commonly causes an insufficient amount of active material in the cathode and therefore inhibits the design of metal-sulfur nanocomposite in sulfur cathodes.To explore the metal/sulfur nanocomposite as a new research trend in sulfur cathodes, we propose a design for a nickel/sulfur nanocomposite as a novel energy-storage material by the electroless nickel plating method, and discuss its applications in lithium–sulfur battery cathodes. The nickel/sulfur energy-storage material possesses metallic nickel on the surface of the insulating sulfur particles as a result of the reduction of nickel ions during autocatalytic plating. By controlling the synthesis and fabrications conditions, the nickel/sulfur energy-storage material attains adjustable high sulfur contents of 60–95 wt% and adjustable high sulfur loadings of 2–10 mg cm−2 in the resulting cathode. The high-loading cathode with the nickel/sulfur energy-storage material demonstrates high electrochemical utilization and stability, which attains a high areal capacity of 8.2 mA∙h cm−2, an energy density of 17.3 mW∙h cm−2, and a stable cyclability for 100 cycles. Results and Discussion Here, in our presentation, we discuss our novel method for the fabrication of nickel/sulfur energy-storage material as an advanced composite cathode material for exploring battery electrochemistry and battery engineering. We adopt a modified electroless-plating method to synthesize nickel/sulfur energy-storage materials characterized by adjustable high sulfur contents and promising cathode performance. The plated nickel coating provides the nickel/sulfur energy-storage materials with metallic conductivity and polysulfide adsorption ability, which addresses the two major issues of sulfur cathodes.[1,2] Therefore, the nickel/sulfur energy-storage material attains high sulfur contents in the cathode and exhibits a high charge-storage capacity of 1,362 mA∙h g−1 and an excellent cyclability for 100 cycles. Moreover, the nickel/sulfur energy-storage material enables high-loading sulfur cathodes with a sulfur loading of 10 mg cm−2, a high areal capacity of 8.2 mA∙h cm−2, and an energy density of 17.3 mW∙h cm−2. Conclusion In summary, the summary of our nickel/sulfur energy-storage materials presented in this presentation would demonstrate a light-weight metallic nickel coating technique for fast charge transfer and strong polysulfide retention in the sulfur nanocomposites composite sulfur cathode. Moreover, our systematic analysis of the nickel/sulfur energy-storage materials exhibits their achievements in attaining both high electrochemical designs of high sulfur content and loading as well as possessing high energy density and electrochemical stability. References C.-S. Cheng, S.-H. Chung, Chem. Eng. J. 2022, 429, 132257.C.-S. Cheng, S.-H. Chung, Batter. Supercaps 2022, 5, e202100323.

(Digital Presentation) Flattening of the Capacitance–Current Density Curve. the Effect of Surface Metallization of Ni(OH)2 on the Electrode for the Hybrid Supercapacitor

During the last decades, the development of supercapacitors (SCs) has become one of the main trends in electrochemistry. This can be explained by the requirements of some autonomous devices in high currents for a short time. Another reason is that the coupling of an accumulator and a SC can be used for the accumulator's lifetime prolongation and increase its performance as well.One of the best-known materials for SCs is nickel hydroxide. It is used in positive electrodes of asymmetric hybrid SCs.In this work, we used the direct formation of Ni(OH)2 on nickel foam followed by its partial metallization by electroless nickel plating in order to define the effect of metallization on the electrochemical performance of formed electrodes.The formation of electrodes was carried out by means of the reaction of nickel ammonia complex decomposition [1]. Cleaned nickel foam substrates were submersed in nickel ammonia complex solution. Full complex self-decomposition was made for two days and certain Ni(OH)2 mass was deposited on substrates. The next step for electrodes was rinsing with distilled water and drying in fresh air for one day. Formed in such a way electrodes were used to define electrode properties without metallization. Several formed electrodes were used for the further metallization step. For this electrodes with Ni(OH)2 were immersed in electrolyte for electroless nickel plating. The composition and work conditions were the following: 30 g/L NiSO4·7H2O, 10 g/L Na2H2PO4·H2O, 30 g /L (NH4)2SO4, pH=8.2, t=85 °C. As a result, several electrodes with different deposited nickel to nickel hydroxide were formed. Formed electrodes were rinsed with distilled water, and dried on air for one day. After that, cyclic voltammetry with different sweep rates (5, 10, 20, 50, 100, 500 mV/s) and charge-discharge cycling (1, 2, 3, 5, 10 A/g) were performed.All reactants were of analytical grade and used without further purification. For the formation of all electrodes, nickel foam (NF) substrates with sizes 1×3.5 cm and the following parameters were used: purity - 99.99%, thickness - 1.6 mm, density - 346 g/m2, porosity ≥95%, 80-110 ppi. In order to estimate morphology, an optical microscope with a digital camera (Hayear 16MP) was used. For electrochemical measurements, Gamry 1010E potentiostat was used. The platinum plate was used as a counter and Ag|AgCl in 3M KCl was employed as a reference electrode. 1M KOH solution was used as an electrolyte in all experiments.It was found that after metallization, the mass change of electrodes was negative. It was proposed that, despite the presence of nickel ions source in the electrolyte, the formed Ni(OH)2 partially or completely transforms into metallic nickel. The negative mass change was used for the estimation of nickel’s minimal mass after metallization.The resulting characteristics of electrodes before and after metallization differed dramatically. For example, the electrodes’ color changed from greenish to grayish before and after metallization – fig 1a. The electrochemical characteristics parameters of metalized and non-metalized electrodes were different as well – fig. 1b. The most interesting was the dependence between specific capacity and current density – fig. 1c. As it is seen, the higher metallization quantity leads to capacity increase, especially in a region with higher current densities. The highest capacity in 188 F/g was found for the electrode with metallization Ni0 ≥ 29% at 10 A/g. This effect can be explained by the increasing local conductivity of Ni(OH)2 and its mechanical properties. The last can prevent Ni(OH)2 shedding from the electrode due to parallel oxygen evolution during the charging process. Conclusions Deposition of nickel hydroxide coupled with a further metallization process can increase the specific capacity of the electrode.The positive effect of metallization can be caused by increasing Ni(OH)2 conductivity and its mechanical durability at oxygen evolution during the charging process. Acknowledgment This work was carried out within the framework of the National Scholarship Program of the Slovak Republic with the assistance of the Slovak Academic Information Agency (S.A.I.A, n.o.), as well as the VEGA 1/0529/20 grant, and by the Ministry of Education, Science, Research and Sport of Slovakia, the Slovak Research and Development Agency under the APVV-21-0278 and APVV 20-0220 contracts References Kovalenko, V., Kotok, V., & Bolotin, A. (2016). Definition of factors influencing on Ni(OH)2 electrochemical characteristics for supercapacitors. Eastern-European Journal of Enterprise Technologies, 5(6), 17-22. doi:10.15587/1729-4061.2016.79406 Figure 1

Chemical black nickel coatings on steels

Having high corrosion resistance and hardness, black conversion coatings are used as functional, as well as protective and decorative coatings. Black chrome and nickel electroplated coatings are mainly used for these purposes. The main drawbacks of the chromium plating processes are related to the fact that they are rather difficult to realize and control and that they consume a great amount of energy as the solutions need to be heated up and some of the heat gets lost during hydrogen evolution reaction. The known black nickel plating processes are less energy intensive and easier to implement, however they have their drawbacks, such as low protective ability and wear resistance and poor adhesion to the substrate, especially to steel. This paper describes certain processes that were tested, as well as two plating techniques for producing black wear-resistant coatings with a high protective ability on chemically deposited nickel-phosphorus layers. It was found that the treatment of black coatings with nitric acid and anodic treatment with phosphoric acid lead to increased roughness and porosity of the coatings. Nickel oxides NiO, Ni2O3, as well as nickel phosphates were found in the final coating. It was established that heat treatment enhances the wear resistance and protective ability of black nickel-phosphorus coatings and they even outperform black chrome and nickel electroplated coatings. The properties of the resulting coatings were studied using an OLYMPUS LEXT4100 confocal laser microscope, a Taber Elcometer 5135 rotary abraser, an EDX-7000 energy-dispersive spectrometer, an HB100 Auger microscope (Vacuum Generators, GB), and a 410 Quick Start Guide reflectometer. The paper demonstrates the possibility of using a safer chemical nickel plating process instead of chromium and nickel electroplating processes.The authors would like to thank the Mendeleev Shared Knowledge Centre for support of this research.

A novel method integrating response surface method with artificial neural network to optimize membrane fabrication for wastewater treatment

Developing high performance membranes is an urgent need to resolve water pollution problem. Electroless nickel plating (ENP) has been emerging as a promising membrane fabrication technique due to its distinct advantages over conventional ones. However, the involved intricate mechanisms and multi-factors impede optimization of this fabrication technique. In this study, a method integrating response surface method (RSM) with artificial intelligence was proposed to optimize ENP conditions for polyvinylidene fluoride-nickel (PVDF-Ni) membrane fabrication. RSM simulation based on experimental data showed the optimal conditions of 30 °C reaction temperature, 14.50 min reaction duration and 9 mL ammonia amount in this study. With the data of experiments designed by RSM as input, the combined RSM-artificial neural network (ANN) method enabled to predict the flux and Congo red (CR) rejection of the optimal membrane. The membrane under the optimal conditions was then fabricated. It was found that, the predicted flux and rejection of the optimal membrane were rather close to the real ones with less relative error of −3.64% and −0.58%, respectively. Scanning electron microscopy (SEM) characterization showed that the optimal membrane had an ordered microporous structure with favorable pore size, suggesting feasibility of the proposed method. The proposed method based on artificial intelligence in this work paved a new way and had universal significance to optimize membrane fabrication.

Environmentally Friendly Nickel Plating Processes

Environmentally Friendly Nickel Plating Processes

A study on the effect of lawsone isolated from Lawsonia inermis linn leaf extract Ni-W-P alloy electroless deposition

Electroless nickel plating has received fascination as a hard coating for industrial applications owing to high hardness, uniform thickness as well as excellent corrosion and wear resistance. The purpose of this research is to investigate the influence of Lawsone extracted from Lawsonia inermis Linn leaf extract on Ni–W–P alloy electroless deposition. SEM, XRD, AFM and EDAX are used to assess the structure, morphologies and corrosion resistance behaviour of Ni-W-P as well as electrochemical methods such as potentiodynamic polarisation curve and electrochemical impedance spectroscopy. The unique Ni–W–P alloy coating has exceptional mechanical qualities as well as good corrosion resistance. The addition of Lawsone improves the corrosion resistance and micro hardness of the deposits while also altering their structure and shape.

Influence of Soft Phase and Carbon Nanotube Content on the Properties of Hierarchical AZ61 Matrix Composite with Isolated Soft Phase.

Carbon nanotube-reinforced magnesium matrix (CNTs/Mg) composite has great application potential in the transportation industry, but the trade-off between strength and ductility inhibits its widespread application. In order to balance the strength and plasticity of the composite, in this work, on the basis of the AZ61 matrix composite homogeneously reinforced by Ni-coated CNTs (hard phase), 30 vol.% large-size AZ61 particles are introduced as an isolated soft phase to fabricate hierarchical CNTs/AZ61 composites. The compression tests show the fracture strain and compressive strength of this composite increases by 54% and 8%, respectively, compared with homogeneous CNTs/AZ61 composite. During deformation, the hard phase is mainly responsible for bearing the load and bringing high strength, due to the precipitation of the Mg17Al12 phase, uniformly dispersed CNT and strong interfacial bonding of the CNTs/Mg interface through nickel plating and interfacial chemical reaction. Furthermore, the toughening of the soft phase results in high ductility. With the increase in CNT content, the compressive strength of composites is nearly unchanged but the fracture strain gradually decreases due to the stress concentration of CNT and its agglomeration.

Numerical simulation of functioning a silicene anode of a lithium-ion battery

The development of next generation lithium-ion batteries (LIB) requires stable anodes with high capacity and long service life. In this work, the molecular dynamics method is used to study the functioning of a combined anode constructed from a nickel plate and two layers of silicene. Such anodes demonstrate high efficiency as opposed to similar anodes with supporting plates made of other metals. The creation of monovacancies in silicene increases the capacity of the anode. The ultimate stresses and strains of a nickel plate and a silicene sheet under uniaxial tension are calculated. When lithium is intercalated into the silicene channel, significant fluctuations in the value of its self-diffusion coefficient are observed. The most significant effect of polyvacancies in the channel walls on the lithium packing in it is manifested at small values of the number of nearest neighbors and small angles of their mutual arrangement. Four- and five-membered rings are most often found in packings of lithium atoms in a channel. The strength of silicene with monovacancies and its adhesion to the nickel plate are sufficient to ensure long and trouble-free operation of the anode in LIB.

Effect of ultrasonic vibration on adhesive enhancement of plasma-modified nickel surface

Poor adhesion of nickel surface limits its further application in the aerospace field. In this study, plasma modification was conducted on the surface of the nickel plate pretreated by sandblasting, and then ultrasonic vibration was applied during the adhesively bonding process of the CFRP(Carbon fibre-reinforced polymer)/Ni joints. The bonding strength of the joints was increased by 65%. The adherend surface and the bonding interface were analyzed from microstructure, element distribution and chemical bonding to study the strengthening mechanism. By the sandblasting, irregular pits were formed on the nickel surface, effectively increasing the surface roughness. The plasma modification could introduce active functional groups including hydroxyl, amino and carbonyl on the nickel surface, which improved the surface wettability macroscopically. However, at a microscopic level, the adhesive with high viscosity and poor fluidity did not form a compact interface with the nickel. The ultrasonic application could promote the filling of the adhesive in irregular micro-scale pits on the surface, thereby strengthening the mechanical anchoring effect. Furthermore, the ultrasonic application produced dynamic impingement at the interface, enhancing the contact between the adhesive and the nickel plate. The adhesive molecules could fully collide and react with the active functional groups introduced on the nickel surface to form more chemical bonds, thus effectively improving the bonding strength of the CFRP/Ni joints.

Perbandingan Karakteristik Sel Superkapasitor Berbahan Komposit GO/TiO2 yang Dibuat Melalui Proses Termal Dengan dan Tanpa Autoclave

The rGO/TiO2 composites were prepared by thermal method using an autoclave and without an autoclave. The rGO/TiO2 composite without an autoclave was prepared from GO dispersion and TiO2 dispersion with a mass ratio of 3:2 through heating at 50 ºC for 5 hours, while the rGO/TiO2 composite with an autoclave was prepared from GO dispersion and TiO2 dispersion with a mass ratio of 3:2 through heating at 120 ºC for 24 hours. As supercapacitor electrodes, the rGO/TiO2 composite layer was deposited on nickel plates (Ni) using the UV Oven spraying technique. The configuration of supercapacitor model was a symmetrical cell that consists of a pair of rGO/TiO2 composite layers on the Ni plate as electrodes and a 1M KOH solution as an electrolyte. The supercapacitor with the electrodes of rGO/TiO2 composite made using autoclaves has higher performance compared to the supercapacitor with the electrodes of rGO/TiO2 composite without autoclave, with the specific capacitance values, specific energy, and specific power of 8.21 F/g, 1.14 Wh/kg, and 164.1 Watt/kg. The performance of the rGO/TiO2 composite supercapacitors are higher than that of supercapacitors using pure GO and TiO2 as electrodes

Wood-Based Composites with High Electromagnetic Interference Shielding Effectiveness and Ultra-Low Reflection

With the aggravation of electromagnetic radiation pollution, it is urgent to develop green, lightweight, ultra-thin and high-performance electromagnetic interference shielding materials to eliminate unnecessary electromagnetic interference; however, the construction of wood-based high-performance electromagnetic shielding materials by simple methods remains a challenge. Based on the layer-by-layer assembly strategy, a lightweight Ni/Wood/Ni composite (NWNC) with an interlayer structure was constructed by a simple electroless plating method using natural wood as a substrate for electromagnetic interference shielding. The synthesized NWNC has a smooth surface, and its minimum surface roughness is only 8.34 μm. After 15 min of electroless nickel plating, the contact angle (CA) of NWNC with an ultra-thin nickel layer (65 μm) was 118.3°. When the thickness of the nickel layer is only 0.102 mm, the conductivity can reach 1659.59 S/cm when the three electroless nickel plating time is 15 min. In the L-band, the electromagnetic shielding effectiveness can reach 94.1 dB after three times electroless nickel plating for 20 min. This is due to the conductive loss, magnetic loss and interface polarization loss generated by the electromagnetic network constructed by the nickel layer, which makes the composite material produce an electromagnetic shielding mechanism dominated by absorption. The L-band absorption efficiency can reach 39.01 dB, and due to the porous structure of the original wood, the multiple reflection and absorption inside the wood further lose the electromagnetic wave. This study provides a low-cost and simple method for the design of light, ultra-thin and efficient controllable wood-based electromagnetic shielding materials and has broad application prospects in the fields of construction and aerospace.