scholarly journals Electrochemical deposition of nickel from aqueous electrolytic baths prepared by dissolution of metallic powder

2021 ◽  
Author(s):  
M. Próchniak ◽  
M. Grdeń
Keyword(s):  
Electrochemical Deposition ◽  
Acidic Solution ◽  
Ph Value ◽  
Additional Treatment ◽  
Alkaline Electrolyte ◽  
Free Surfaces ◽  
Ni Powder ◽  
Ca 50 ◽  
Fast Dissolution ◽  
Acidic Bath

AbstractA new method of preparation of aqueous electrolyte baths for electrochemical deposition of nickel targets for medical accelerators is presented. It starts with fast dissolution of metallic Ni powder in a HNO3-free solvent. Such obtained raw solution does not require additional treatment aimed to removal nitrates, such as the acid evaporation and Ni salt precipitation-dissolution. It is used directly for preparation of the nickel plating baths after dilution with water, setting up pH value and after possible addition of H3BO3. The pH of the baths ranges from alkaline to acidic. Deposition of 95% of ca. 50 mg of Ni dissolved in the bath takes ca. 3.5 h for the alkaline electrolyte while for the acidic solution it requires ca. 7 h. The Ni deposits obtained from the acidic bath are physically and chemically more stable and possess smoother and crack-free surfaces as compared to the coatings deposited from the alkaline bath. A method of estimation of concentration of H2O2 in the electrolytic bath is also proposed.

scholarly journals Effect of Artificial Saliva on the Apatite Structure of Eroded Enamel

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaojie Wang ◽  
Boriana Mihailova ◽  
Arndt Klocke ◽  
Stefanie Heidrich ◽  
Ulrich Bismayer
Keyword(s):  
Citric Acid ◽  
Ph Value ◽  
Artificial Saliva ◽  
Additional Treatment ◽  
Attenuated Total Reflectance ◽  
Apatite Structure ◽  
Total Reflectance ◽  
Time Period ◽  
The Individual ◽  
Induced Changes

Citric acid-induced changes in the structure of the mineral component of enamel stored in artificial saliva were studied by attenuated total reflectance infrared spectroscopy as well as complementary electron probe microanalysis and scanning electron microscopy. The results indicate that the application of artificial saliva for several hours (the minimum time period proved is 4 h) leads to slight, partial recovering of the local structure of eroded enamel apatite. However, artificial saliva surrounding cannot stop the process of loosening and breaking of P–O–Ca atomic linkages in enamel subjected to multiple citric acid treatments. Irreversible changes in the atomic bonding within 700 nm thick enamel surface layer are observed after three times exposure for 1 min to aqueous solution of citric acid having a pH value of 2.23, with a 24-hour interval between the individual treatments. The additional treatment with basic fluoride-containing solutions (1.0% NaF) did not demonstrate a protective effect on the enamel apatite structure per se.

Oxidative Decolorization of Azo Dyes with Copper Phthalocyanine Supported Mg-Al Hydrotalcites

2016 ◽  
Vol 703 ◽  
pp. 306-310
Author(s):  
Min Hong Xu ◽  
Jian Li Ma ◽  
Meng Xia Qian ◽  
Hui Na Qin
Keyword(s):  
Molecular Structure ◽  
Methylene Blue ◽  
Methyl Orange ◽  
Azo Dyes ◽  
Acidic Solution ◽  
Copper Phthalocyanine ◽  
Ph Value ◽  
Influence Factors ◽  
Amido Black ◽  
Initial Ph

Oxidative decolorization of azo dyes with a heterogeneous catalyst copper phthalocyanine supported Mg-Al hydrotalcites was studied and the influence factors such as initial pH value, temperature, H2O2 and CuPc-LDHs/H2O2 system were discussed. The results indicated that acidic solution and high temperature were conducive to oxidative decoloration of methyl orange. CuPc-LDHs/H2O2 system showed excellent oxidative decoloration capacity to remove azo dyes. The effects of oxidative decolorization of azo dyes were related to the molecular structure and weight of azo dyes. Oxidative decoloration effects followed the order as congo red > amido black > methyl blue> methyl orange> methylene blue.

Selective purification of bleached spruce TMP process water by induced air flotation (IAF)

Holzforschung ◽  
2014 ◽  
Vol 68 (2) ◽  
pp. 157-165 ◽  
Author(s):  
Dariusz Zasadowski ◽  
Anders Strand ◽  
Anna Sundberg ◽  
Håkan Edlund ◽  
Magnus Norgren
Keyword(s):  
Ph Value ◽  
Additional Treatment ◽  
Process Water ◽  
Ionization Mass ◽  
Paper Mills ◽  
Foaming Agent ◽  
Peroxide Bleaching ◽  
Alkaline Peroxide ◽  
Thermomechanical Pulping ◽  
Air Flotation

Abstract The environmentally benign closure of water systems in paper mills leads to the problem of accumulation of dissolved and colloidal wood substances (DCS) in process water. Notably, pitch affects the pulp and paper production negatively and increases the demand for additional treatment of the process water. In the present article, the purification of thermomechanical pulping process water from the alkaline peroxide bleaching stage has been investigated, with the induced air flotation (IAF) in focus. The following parameters were considered concerning the IAF efficiency to remove detrimental substances: concentration of cationic foaming agent, pH value, calcium concentration, and temperature. The amounts and characteristics of residual DCS were determined by gas chromatography and turbidity measurements. Residual concentrations of the foaming agent dodecyltrimetylammonium chloride were determined by electrospray ionization mass spectrometry. Up to 90% of pitch was removed, whereas hemicelluloses, which are important in preventing pitch problems, remained in the waters. Up to 70% of the pectic acids accounted for the high cationic demand of the process waters were removed by optimization of the IAF parameters. The presented separation process gives new opportunities to a selective purification of the process waters.

scholarly journals Molecular Modeling of Acidic Treated PSTM-3T Polymer for Removal of Heavy Metal Ions by Experimental and Computational Studies

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Natsagdorj Narantsogt ◽  
Gunchin Burmaa ◽  
Adiya Perlee-Oidov ◽  
Nyamdorj Shurkhuu ◽  
Namsrai Javkhlantugs
Keyword(s):  
Molecular Structure ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Density Functional ◽  
Acidic Solution ◽  
Ph Value ◽  
Density Functional Theory Method ◽  
Structure Change ◽  
Sorption Efficiency

The synthesized poly[N,N′-bis(3-silsesquioxanilpropyl)-thiocarbamide] (PSTM-3T) was used and the surface morphology and microstructure of it were analyzed by scanning electron microscopy with energy dispersive spectrometer (SEM/EDS). The molecular structure change of the PSTM-3T polymer of the PSTM-3T after treatment by acidic solution with different pHs was revealed using FT-IR experiments andab initiocalculations with density functional theory method. The sorption efficiency of the heavy metal ions depends on the molecular structure change of PSTM-3T after treatment of different pH aqueous solutions. After the treatment of acidic solution (pH = 2) of PSTM-3T, the polymer formed the tautomer state to increase the sorption efficiency for chromate ion. For the increment of pH value for acidic solution, the PSTM-3T polymer was dissociated to increase the sorption efficiency for copper ion.

Facile electrochemical synthesis of titanium dioxide dendrites and their electrochemical properties

2015 ◽  
Vol 51 (16) ◽  
pp. 3391-3394 ◽  
Author(s):  
Sang Ha Lee ◽  
Hyuck Lee ◽  
Misuk Cho ◽  
Youngkwan Lee
Keyword(s):  
Titanium Dioxide ◽  
Electrochemical Properties ◽  
Electrochemical Deposition ◽  
Electrochemical Synthesis ◽  
Acidic Solution ◽  
Deposition Technique

Titanium dioxide dendrites were successfully prepared by a simple electrochemical deposition technique in acidic solution.

scholarly journals Magnesium Doped Hydroxyapatite-Based Coatings Obtained by Pulsed Galvanostatic Electrochemical Deposition with Adjustable Electrochemical Behavior

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 727 ◽  
Author(s):  
Diana Maria Vranceanu ◽  
Ionut Cornel Ionescu ◽  
Elena Ungureanu ◽  
Mihai Ovidiu Cojocaru ◽  
Alina Vladescu ◽  
...  
Keyword(s):  
Phase Composition ◽  
Dissolution Rate ◽  
Electrochemical Deposition ◽  
Electrochemical Behavior ◽  
Body Fluid ◽  
Electrochemical Cell ◽  
Ph Value ◽  
Pure Water ◽  
Ultra Pure Water ◽  
Pulsed Mode

The aim of this study was to adapt the electrochemical behavior in synthetic body fluid (SBF) of hydroxyapatite-based coatings obtained by pulsed galvanostatic electrochemical deposition through addition of Mg in different concentrations. The coatings were obtained by electrochemical deposition in a typical three electrodes electrochemical cell in galvanic pulsed mode. The electrolyte was obtained by subsequently dissolving Ca(NO3)2·4H2O, NH4H2PO4, and Mg(NO3)2·6H2O in ultra-pure water and the pH value was set to 5. The morphology consists of elongated and thin ribbon-like crystals for hydroxyapatite (HAp), which after the addition of Mg became a little wider. The elemental and phase composition evidenced that HAp was successfully doped with Mg through pulsed galvanostatic electrochemical deposition. The characteristics and properties of hydroxyapatite obtained electrochemically can be controlled by adding Mg in different concentrations, thus being able to obtain materials with different properties and characteristics. In addition, the addition of Mg can lead to the control of hydroxyapatite bioactive ceramics in terms of dissolution rate.

Treatment of Model Wastewater Including Eriochrome Black T Based on Eggshell Membrane

2011 ◽  
Vol 183-185 ◽  
pp. 2120-2123 ◽  
Author(s):  
Tao Liu
Keyword(s):  
Azo Dye ◽  
Acidic Solution ◽  
Ph Value ◽  
Dye Adsorption ◽  
Water Soluble ◽  
Eggshell Membrane ◽  
Dye Wastewater ◽  
Optimum Conditions ◽  
Eriochrome Black T ◽  
Pollution Problem

The adsorption and decolorization of water-soluble azo dye(Eriochrome Black T) was investigated based on eggshell membrane. The effect of adsorption time, pH value, temperature as well as the dosage of eggshell membrane on the decolorization of Eriochrome Black T was studied. It is indicated from the experimental results that the azo-dye adsorption with eggshell membrane should be carried out in acidic solution. At the optimum conditions, 95% of Eriochrome Black T could be removed. In this study, the dumped eggshell membrane can be utilized to solve the pollution problem of dye wastewater, which will offer us a new way for utilization of eggshell membrane and treatment of wastewater.

scholarly journals Analysis of Mudstone Fracture and Precursory Characteristics after Corrosion of Acidic Solution Based on Dissipative Strain Energy

2021 ◽  
Vol 13 (8) ◽  
pp. 4478
Author(s):  
Dong Xu ◽  
Yu Wu ◽  
Kewang Cao ◽  
Naseer Muhammad Khan ◽  
Sajjad Hussain ◽  
...  
Keyword(s):  
Strain Energy ◽  
Acidic Solution ◽  
Ph Value ◽  
Rate Of Change ◽  
Chemical Solution ◽  
Solution Ph ◽  
Energy Characteristics ◽  
Chemical Corrosion ◽  
Rock Samples ◽  
Failure Precursor

The deformation and failure of rock materials are closely related to the strain energy characteristics during the loading process. These strain energy characteristics and rock properties are greatly affected when the rock is subjected to the acidic solution. To study the effects of chemical solutions with different pH on the mechanical properties and strain energy mechanism of mudstone, the chemical corrosion mudstone samples are subjected to a uniaxial loading testing machine (CN64 electro-hydraulic servo). The corrosive effects of the acidic solution on the porosity, strain energy characteristics, and failure mode of mudstone samples were thoroughly investigated. The findings of this research indicate that: (1) The rate of change in the porosity and chemical damage coefficient of rock samples after chemical corrosion decreases, which is closely linear with the increase of solution pH; (2) The total strain energy, elastic strain energy, and dissipative strain energy decrease with the increase of pH, and, as a result, it is proposed that the observed turning point of the proportion curve of dissipated strain energy from decline to rise is used as a precursor point of the rock failure; (3) The stress value of the failure precursor point increases and the strain value decreases with the increase in pH value. However, the ratio of the stress value of the failure precursor point to the peak stress hardly changes with pH value, and its value is about 0.883; and (4) Rock samples soaked in a weak acidic chemical solution (pH 7.3 and 5.3) are damaged by tensile crack, while rock samples soaked in a strong acidic chemical solution (pH 3.3 and 1.3) are mainly damaged by the combination of tensile and shear. The findings of this study can be used to provide an experimental and theoretical foundation for monitoring rock engineering disasters such as slope, tunnel, and coal mine failures.

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