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The purpose of this study is to improve the performance of sodium borohydride in reducing indigo at room temperature, the divalent copper ion complex was combined with electrochemical technology for the reduction of indigo by sodium borohydride.

According to the K/S value of the dyed cloth sample, find a more suitable ligand for the copper ion in the catholyte. Response surface analysis tests were performed to evaluate the effects of sodium borohydride concentration, sodium hydroxide concentration and copper sulfate pentahydrate concentration on the reduction potential of the dye solution and the K/S value of the dyed fabric samples.

Sodium gluconate was found to be a more suitable ligand for copper ions in catholyte. The effects of NaOH concentration as well as the interaction of NaBH₄ and NaOH on the reduction potential of the catholyte and the K/S value of the dyed fabric samples were extremely significant. The optimal concentrations of NaBH₄, NaOH and CuSO₄•5H₂O were 0.5, 2.5 and 0.65 g/L. In the case of the optimized condition, the absolute value of the reduction potential was 968, and the K/S value was 11.92, which is comparable with that of the conventional reduction process with sodium dithionite.

The divalent copper ion complex combined with electrochemical technology was applied in the process of reducing indigo with NaBH₄ at room temperature.

This study aims to investigate the behavior of the green biomass-derived copper (lignin/silica/fatty acids) complex, copper lignin/silica/fatty acids (Cu-LSF) complex, when incorporated into the nonpolar ethylene propylene diene (EPDFM) rubber matrix, focusing on its reinforcing and antioxidant effect on the resulting EPDM composites.

The structure of the prepared EPDM composites was confirmed by Fourier-transform infrared spectroscopy, and the dispersion of the additive fillers and antioxidants in the EPDM matrix was investigated using scanning electron microscopy. Also, the rheometric characteristics, mechanical properties, swelling behavior and thermal gravimetric analysis of all the prepared EPDM composites were explored as well.

Results revealed that the Cu-LSF complex dispersed well in the nonpolar EPDM rubber matrix, in thepresence of coupling system, with enhanced Cu-LSF-rubber interactions and increased cross-linking density, which reflected on the improved rheological and mechanical properties of the resulting EPDM composites. From the various investigations performed in the current study, the authors can suggest 7–11 phr is the optimal effective concentration of Cu-LSF complex loading. Interestingly, EPDM composites containing Cu-LSF complex showed better antiaging performance, thermal stability and fluid resistance, when compared with those containing the commercial antioxidants (2,2,4-trimethyl-1,2-dihydroquinoline and N-isopropyl-N’-phenyl-p-phenylenediamine). These findings are in good agreement with our previous study on polar nitrile butadiene rubber.

The current study suggests the green biomass-derived Cu-LSF complex to be a promising low-cost and environmentally safe alternative filler and antioxidant to the hazardous commercial ones.

The purpose of this study is to study the mechanical, tribological and electrical properties of the copper-graphene (Cu-Gn) composites fabricated by a novel rapid tooling technique consist of three-dimensional printing and ultrasonic-assisted pressureless sintering (UAPS).

Four different Cu-Gn compositions with 0.25, 0.5, 1 and 1.5 per cent of graphene were fabricated using an amalgamation of three-dimensional printing and UAPS. The polymer 3d printed parts were used to prepare mould cavity and later the UAPS process was used to sinter Cu-Gn powder to acquire free-form shape. The density, hardness, wear rate, coefficient of friction and electrical conductivity were evaluated for the different compositions of graphene and compared with the pure copper. Besides, the comparison was performed with the conventional method.

Cu-Gn composites revealed excellent wear properties due to higher hardness, and the lubrication provided by the graphene. The electrical conductivity of the fabricated Cu-Gn composites started increasing initially but decreased afterwards with increasing the content of graphene. The UAPS fabricated composites outperformed the conventional method manufactured samples with better properties such as density, hardness, wear rate, coefficient of friction and electrical conductivity due to homogeneous mixing of metal particles and graphene.

The fabrication of Cu-Gn composite freeform shapes was found to be difficult using conventional methods. The novel technique using a combination of polymer three-dimensional printing and UAPS as rapid tooling was introduced for the fabrication of freeform shapes of Cu-Gn composites and mechanical, tribological and electrical properties were studied. The method can be used to fabricate optimized complex Cu-Gn structures with improved wear and electrical applications.

Recent studies have shown that the type of dietary carbohydrate consumed greatly affects copper homeostasis. Simple sugars such as sucrose and fructose exacerbate the signs associated with the deficiency, and the consumption results in the mortality of the animal. In contrast, complex carbohydrates such as starch ameliorates the deficiency and protects against the morbidity and mortality of copper deficiency. This is the first of a two‐part article in which the effects of dietary carbohydrates on metabolic, biochemical and physiological pathways associated with copper deficiency in experimental animals and humans are summarised. In the first part of the review the effects that dietary carbohydrates exert on copper absorption, distribution and excretion are discussed. In addition, the role that copper plays in carbohydrate metabolism, insulin secretion and binding, glucose tolerance and the complications of diabetes (retinopathy and glomerular nephropathy) is reviewed. In the second part, the attention is focused on the cardiovascular system, sexual differences in copper‐carbohydrate interaction and copper deficiency during pregnancy and lactation. The mechanisms that may play a role in this interaction are discussed.

The purpose of this paper is to perform the evaluation of copper susceptibility to corrosion in industrial cooling systems. Microstructure and defects of copper are observed, while divergences from optimum structure are discussed.

Various types of corrosion are examined. Electrochemical techniques such as electrochemical impedance spectroscopy and potentiodynamic polarisation are applied in these materials, using corrosion inhibitors. Microscopic observations and electrochemical measurements are interpreted according to possible mechanistic scenarios.

It is evident that, under specific conditions (e.g. high pH), water cooling ingredients can enhance corrosion, leading to significant copper mass loss from the inner surface of the pipe and thus leading to failure.

Evaluation of copper corrosion in cooling industrial systems was done, as well as studies of copper corrosion in sodium chloride.

The emergence of new interconnection technologies involving double‐sided surface mounted components has put stronger restrictions on the method of preserving the solderable finish on printed circuit (PC) boards. The popular Sn/Pb coatings have come under strong scrutiny due to environmental hazards of lead and also because they do not provide flat, planar surfaces for SM assembly. Organic solderability preservative coatings (OSP) are emerging as strong contenders for replacing Sn/Pb surface finishes. Benzotriazole based organic coatings have been successfully used in the past by several electronics manufacturers. However, assembly technologies involving multiple thermal operations have necessitated a fundamental understanding of the thermal stabilities and the mechanism of corrosion protection provided by the OSPs. This paper reports the results of an investigation of the thermal stabilities of two organic corrosion protection coatings. Although both are organic azole based, they operate in two distinct regimes: one forming thin films (∼100 Å) and the other forming thick films (∼5000 Å). The mechanism of surface protection has been studied using direct surface analytical techniques such as X‐ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), scanning transmission electron microscopy (SEM/TEM) and Fourier transform infrared spectroscopy (FT‐IR). The solderability of the copper was measured by wetting balance techniques and correlated to the amount of copper oxidation. The results indicate that, although the thin films provide excellent protection for storage and handling operations, they decompose under heat, thereby causing oxidation of the copper. The thick films appear to withstand multiple thermal cycling. However, the underlying copper substrate can still be oxidised by oxygen diffusion through pores or cracks, or the film may undergo chemical changes that render the copper unsolderable.

Benzotriazole is a specific corrosion inhibitor for copper and copper alloys. It is now widely used in industry to reduce the corrosion of these alloys under both atmospheric and immersed conditions. Corrosion of copper may produce a surface stain or tarnish, pitting of surfaces of pipes or promote pitting of other metals, such as aluminium, which are in contact with dissolved copper in the water. Benzotriazole is used to reduce these forms of attack and the methods by which it is applied are discussed in this paper.

This paper describes a state‐of‐the‐art process for immersion tin plating of PCBs which is used to preserve solderability prior to assembly. The process sequence is described and preventive measures for handling the final surface finish is documented. A solderability test method and basic requirements for fluxes and soldering parameters are also described. Quantitative results on the formation of intermetallic tin‐copper phases are shown and their influence on the formation of tin whiskers explained. A problem in production is the precise measurement of the tin thickness, therefore different measuring methods are also detailed. Finally, the mechanism of tin deposition and the formation of tetravalent tin and the relationship with bath age and deposit quality are discussed.

To correlate the inhibitory effect of triazole compounds on the corrosion of copper in HCl at various temperatures by semi‐empirical molecular orbital theory.

Two triazoles were selected as the best inhibitors among the triazole compounds tested. Gravimetric and electrochemical measurements were conducted.

Correlation between inhibition efficiency and calculation of molecular orbital of triazole compounds was obtained. Cu(I)‐triazole complex formation was confirmed by UV spectroscopy.

The calculation of energetic levels of molecular orbital may be a tool to explain the classification of inhibitor efficiency.

The theoretical calculation is a complementary mean to selecting an efficient inhibitor among a given series. Good agreement between the experimental methods explored and theoretical calculations was observed.

The originality of this work was the finding of the correlation between energetic levels of orbital molecular and inhibitor efficiency of triazole compounds. The confirmation of the formation of Cu(I)‐triazole by UV‐visible spectroscopy was also new.

Herein, this study aims to use our recently tailored and fully characterized poly acrylonitrile (AN)-starch nanoparticle graft copolymer having 60.1 graft yield percentage as a starting substrate for copper ions removal from wastewater effluent after chemical modification with hydroxyl amine via oximation reaction as a calorimetric sensor.

The calorimetric sensor batch technique was used to determine the resin's adsorption capacity, while atomic adsorption spectrometry was used to determine the residual copper ions concentration in the filtrate before and after adsorption. This was done to convert the copolymer's abundant nitrile groups into amidoxime groups, and the resulting poly (amidoxime) resin was used as a copper ion adsorbent. To validate the existence of amidoxime groups, the resin was qualitatively characterized using a rapid vanadium ion test and instrumentally using Fourier transform infrared spectroscopy spectra and scanning electron microscopy morphological analysis.

At pH 7, 400 ppm copper ions concentration and 0.25 g adsorbent at room temperature, the overall adsorption potential of poly (amidoxime) resin was found to be 115.2 mg/g. The process's adsorption, kinetics and isothermal analysis were examined using various variables such as pH, contact time, copper ion concentration and adsorbent dose. To pretend the adsorption kinetics, various kinetics models, including pseudo-first-order and pseudo-second-order, were applied to the experimental results. The kinetic analysis indicated that the pseudo-second-order rate equation promoted the development of the chemisorption phase better than the pseudo-first-order rate equation. In the case of isothermal investigations, a study of observed correlation coefficient (R²) values indicated that the Langmuir model outperformed the Freundlich model in terms of matching experimental data.

To the best of the author's information, there is no comprehensive study for copper ions removal from waste water effluent using the recently tailored and fully characterized poly (AN)-starch nanoparticle graft copolymer having 60.1 graft yield percentage as a starting substrate after chemical modification with hydroxyl amine via oximation reaction as a calorimetric sensor.