Production of Nano-Composite Hydroxyapatite-Based Coatings through Reverse Pulse Electroplating

Since the discovery of synthetic HAp in the 1950s, hydroxyapatite is becoming a significant covering material for bio implants. A regulated surface roughness/porosity, appropriate chemical resistance, and a desirable tri-biological behavior are required for HAp coatings. On substrates with a variety of structure, composition, size, and shape, the coating process must be applied at varied scales and at a fast enough rate. There is a full description of both dry and wet coating procedures included in this article. Cathode efficiency fell as tc- increased, although it was still better than DC coatings. In this paper, the mechanism of HAp electrodeposition is examined, as well as the effect of operational variables on deposit characteristics. Recent advances in the field are critically examined. HAp composite coatings, including those reinforced with metallic, ceramic, and polymeric particles, as well as nanotubes, modified graphene’s, chitosan, and heparin, are discussed in depth. On the other hand, a glance towards the future in the field of electrodeposited HAp coatings is taken. Different experimental parameters were explored to establish the optimal reaction conditions for HA-Ag nanocomposites. Pulse reverse plating (PRP) in combination with an anionic surfactant, sodium dodecylsulphate (SDS), was utilized for the first time to generate nanocomposite Co-Al2O3 electrodeposited coatings, using a technique similar to that used for Co – IF WS2 deposition in prior work. The optimal plating setups in the pulse-reverse electroplating (PRP) mechanism for non-anomalous plating of Co–Ni deposits (i.e., the metal composition of deposits equals that of the plating solutions) from chloride solutions were determined using experimental strategies such as fractional factorial design (FFD), path of steepest ascent, and central composite design (CCD) combined with the response surfaces (RSM). The FFD research found that the potentials and time duration of pulse-plating had a significant impact on the composition of Co–Ni deposits. The two parameters were the sharpest ascending route and the best circumstances for non-anomalous plating of Co–Ni layers. NiFe thin films produced by pulse reverse (PR) electrodeposition are potential alternatives for the next phase of core magnetic materials that will be utilized in high shifting frequency magnetic elements. For statistical modeling and analysis of the nickel electroplating process outcomes, the central composite experimental design and response surface technique were used. The empirical models developed in terms of design variables (current density J (A/dm2), temperature T (C), and pH) were found to be statistically adequate to describe the process responses, namely cathode efficiency Y%, coating thickness U (m), brightness V%, and hardness W%. (HV). The response surfaces were explored and analyzed using graphical representations consisting of 2D contour plots and 3D surface plots in order to determine the main, quadratic, and interaction effects. The desirability function method was used to do multi-response optimization of the nickel electroplating process. To this aim, a genetic algorithm was employed to solve the multi-response issue mathematically. The optimization method resulted in the Pareto optimum set, which is a collection of similar solutions.

Recycling of Expired Ceftamil Drug as Additive in the Copper and Nickel Electrodeposition from Acid Baths

Due to the large quantity of expired and unused drugs worldwide, pharmaceutical disposal has become a serious problem that requires increased attention. In the present paper, the study on recycling ceftazidime (CZ) as an additive in copper and nickel electrodeposition from acid baths is highlighted. CZ is the active substance from expired commercial drug Ceftamil®. Its electrochemical behavior was studied by cyclic voltammetry. As well, kinetic parameters for copper and nickel electrodeposition were determined using Tafel plots method at different temperatures and CZ concentrations in these acid baths. The activation energy was calculated from Arrhenius plots. Electrochemical impedance spectroscopy was used to investigate the charge transfer resistance and coverage degree in the electrolyte solutions at several potential values. Gibbs free energy values, calculated from Langmuir adsorption isotherms, revealed the chemical nature of CZ–electrode surface interactions. The favorable effect of the organic molecules added in copper and nickel electroplating baths was emphasized by optical microscope images. The morphology of the obtained deposits without and with 10−4 mol L−1 CZ was compared. The experimental results revealed that expired Ceftamil® is suitable as additive in copper and nickel electroplating processes from acid baths.

Effect of Current and Coating Time on the Layer Thickness and Corrosion Rate of Electroplated AISI 1045

Corrosion mostly occurs on carbon steel which is applied for automotive components and household needs. This natural phenomenon is impossible to be avoided. However, it can be set by escalating its corrosion initiation time. Electroplating is a method that can be used to give protection to slower the corrosion initiation time by forming a layer on the specimen surface, additionally, this method is simple and low cost. One of the most commonly used metals for electroplating is nickel, nickel electroplating is suitable for automotive component coating. For these reasons, this study is focused on analyzing the effect of current and coating time on the layer thickness and corrosion rate of AISI 1045 carbon steel with nickel electroplating. The current variations used were 0.5; 1.0; and 1.5 A and the coating time variations were 5, 10, and 15 minutes. AISI 1045 was used as the cathode, nickel was as the anode, and nickel chloride was the electrolyte solution. The specimen with a current of 1.5 A and a coating time of 15 minutes shows the thickest coating and the lowest corrosion rate, with values of 0.0205 mm and 0.94 mpy, respectively. This study indicates that the increase of the current and coating time enhances the layer thickness and declines the corrosion rate.

Integrated Assessment of Nickel Electroplating Industrial Wastewater Effluent as a Renewable Resource of Irrigation Water Using a Hydroponic Cultivation System

Nickel, a micronutrient essential for plant growth and development, has been recognized as a metallic pollutant in wastewater. The concentration of nickel ions in the water course, exceeding the maximum tolerable limit, has called for an alarming attention, due to the bioaccumulative entry in the water–plant–human food chain, leaving a burden of deteriorative effects on visible characteristics, physiological processes, and oxidative stress response in plants. In this work, the renewable utilization of nickel electroplating industrial wastewater effluent (0, 5, 10, 25, 50, and 100%) as a viable source of irrigation water was evaluated using a hydroponic cultivation system, by adopting Lablab purpureus and Brassica chinensis as the plant models, in relation to the physical growth, physiological and morphological characteristics, photosynthetic pigments, proline, and oxidative responses. The elongation of roots and shoots in L. purpureus and B. chinensis was significantly inhibited beyond 25 and 5% of industrial wastewater. The chlorophyll-a, chlorophyll-b, total chlorophyll, and carotenoid contents, accompanied by alterations in the morphologies of xylem, phloem, and distortion of stomata, were recorded in the industrial wastewater-irrigated groups, with pronounced toxicity effects detected in B. chinensis. Excessive proline accumulation was recorded in the treated plant models. Ascorbate peroxidase (APX), guaiacol peroxidase (POD), and catalase (CAT) scavenging activities were drastically altered, with a profound upregulation effect in the POD activity in L. purpureus and both POD and APX in B. chinensis, predicting the nickel-induced oxidative stress. Conclusively, the diluted industrial wastewater effluent up to the optimum concentrations of 5 and 25%, respectively, could be feasibly reused as a renewable resource for B. chinensis and L. purpureus irrigation, verified by the minimal or negligible phytotoxic implications in the plant models. The current findings have shed light on the interruption of nickel-contaminated industrial wastewater effluent irrigation practice on the physical and biochemical features of food crops and highlighted the possibility of nutrient recycling via wastewater reuse in a sustainable soilless cultivation.