Complex Salt Solution Research Articles

Pseudo-bottle-brush decorated thin-film composite desalination membranes with ultrahigh mineral scale resistance.

High water recovery is crucial to inland desalination but is impeded by mineral scaling of the membrane. This work presents a two-step modification approach for grafting high-density zwitterionic pseudo-bottle-brushes to polyamide reverse osmosis membranes to prevent scaling during high-recovery desalination of brackish water. Increasing brush density, induced by increasing reaction time, correlated with reduced scaling. High-density grafting eliminated gypsum scaling and almost completely prevented silica scaling during desalination of synthetic brackish water at a recovery ratio of 80%. Moreover, scaling was effectively mitigated during long-term desalination of real brackish water at a recovery ratio of 90% without pretreatment or antiscalants. Molecular dynamics simulations reveal the critical dependence of the membrane's silica antiscaling ability on the degree to which the coating screens the membrane surface from readily forming silica aggregates. This finding highlights the importance of maximizing grafting density for optimal performance and advanced antiscaling properties to allow high-recovery desalination of complex salt solutions.

Obtaining of Water-soluble Complex Salts of Various Fractions of Synthetic Petroleum Acids and Alcoamines, Investigation of Their Effect on Triticum, Zea mays and Pisum sativum, and Comparative Analysis With Natural Petroleum Acid Complexes

The purpose of our research is to summarize information about oil, the use of various fractions of natural and synthetic petroleum acids (boiling away in the ranges of 125-175°C; 175-225°C; 125-225°C, the synthesis of their water-soluble complex salts with alkanolamines (mono-, di-, tri-) by the reaction of their interaction with monoethanolamine, diethanolamine and triethanolamine, determination of their IR spectra, melting point and refractive index, preparation of solutions with different percentage concentrations (0.05; 0.01; 0.005; 0.001; 0.0001% solutions), the study of the electrical conductivity of solutions, laboratory and field studies of these compounds as growth compounds for Triticum, Zea mays and Pisum sativum. First, the seeds are soaked in the appropriate solutions in Petri dishes. Then the seeds taken in a plastic container are planted into the ground in accordance with the depth of planting and the number of seeds. The degree of germination is calculated from the number of germinated seeds. To determine the effect of salt solutions on the growth dynamics of the aerial parts of plants and roots in laboratory conditions, observations and measurements are carried out for 14-15 days. At the next stage, experiments are carried out in the field and the final results are obtained. Comparing the obtained results of the effect of complex salt solutions synthesized on the basis of natural and synthetic petroleum acids on plants both with each other and with the control variant (that is, with seedlings obtained from seeds soaked in irrigation water), it is determined which complex salts have better effect on plant development.

Micro-Arc Oxidation Phenomenon for Producing Coatings of AZ31B Mg Alloy Using Na3PO4 with Varying KOH Concentrations and Voltages: A Study

Complex salt solution systems are commonly used as electrolytes for microarc oxidation (MAO). To investigate the MAO phenomenon in simple electrolytes and evaluate the efficacy of MAO coatings, an Na3PO4 monosalt solution was used as the MAO electrolyte. In this study, the effects of the voltage and Na3PO4 concentration on the spark discharge phenomenon, thickness, roughness, and corrosion resistance of the coatings were investigated. The results showed that MAO coatings were effectively synthesised at high concentrations and voltages. Furthermore, the addition of KOH to the Na3PO4 monosalt solution resulted in discernible spark discharge and improved the corrosion resistance of the coatings. Thus, an MAO coating can be efficiently prepared using Na3PO4 solution as the electrolyte. In addition, the addition of KOH to the Na3PO4 monosalt solution reduced the voltage required for coating formation and enhanced the corrosion resistance of the coating.

Artificial neural network modelling for solubility of carbon dioxide in various aqueous solutions from pure water to brine

Predicting the solubility of CO2 in various aqueous solutions, such as pure water, brackish water, saline water and brine, has become increasingly important because of the interdisciplinary significance of carbon dioxide solubilization, particularly in the energy and environmental fields. Despite experimental difficulties, the solubility of CO2 in various aqueous solutions of single and multi-salt was measured under limited conditions for specific purposes. In this study, artificial neural network (ANN) model was applied to the solubility data of CO2 (2406 experimental data) in salt-dissolved solutions over a wide range of pressures (0.92–712.31 bar), temperatures (273.15–473.65 K), concentrations of electrostricted water molecules (0–90.12 mol/kgw), and overall mole fractions of dissolved salts (0–25.39 mol%), including supercritical condition of CO2. Compared with the conventional thermodynamic models using many parameters, the accuracy of ANN model with only four input variables was comparable for salt solutions and even feasible for brine-rock systems. While the average of the absolute relative deviation of the thermodynamic model with respect to CO2 solubility data in pure water and single-salt solution (1556 data of total 2406 data) was 5.44 %, that of the developed ANN model for the corresponding data was 4.90 %. The developed ANN model presented the capability of dimensional extrapolation in the prediction of CO2 solubility in salt solutions without over-fitting when the thermodynamic-based input variable was used. The model for the solubility prediction of non-polar gases in salt solutions could be a useful approach in complex salt solutions under a wide range of temperature and pressure.

Na+/Mg2+ interactions on membrane distillation permeation flux and crystallization performance during high saline solution treatment

Membrane distillation crystallization (MDC) was an effective method for saline solution treatment to simultaneously recovery pure water and salt products. In MDC process, an important topic was the influence of ionic interactions produced by complex salt solution on MDC performance. We processed a typical ternary saturated solution (Na+/Mg2+//Cl-–H2O) with MDC to investigate the influence of different Na+/Mg2+ ratios on membrane distillation permeation flux and crystal morphology from the perspective of experiment and molecular dynamics simulation. From the simulation results, it was demonstrated that increasing magnesium ions could modify the hydration structure of the cations and influence the diffusion coefficient of the hydrated ions in the solution. The reduced free water and diffusion ability led to the changes in permeation flux and crystal morphology. The crystals with different morphologies could be produced by adjusting the ratio of Na+/Mg2+ and MDC temperature. In addition, selective solvent (ethanol) wash approach was developed to further improve the separation performance and reveal the effect of Mg2+ on NaCl crystal growth.

How does the ethoxylated grafting of polyelectrolytes affect the self-assembly of polyanion-cationic surfactant complex salts?

A cationic surfactant and different anionic copolymers randomly grafted with side chains of ethylene oxide were used to prepare stoichiometric complex salts. Variations in the length or proportion of side chains were shown to be responsible for affecting the surfactant phase behavior in water, resulting in the observation of a number of structures characterized by small angle X-ray scattering measurements, including a hierarchical micellar system and different liquid-crystalline phases. Additionally, although aqueous mixtures of stoichiometric complex salts usually phase separate, the presence of a sufficiently high weight fraction of ethylene oxide side chains can enhance the solubility of the complex salt aggregates in water over a wide range of concentration. Moreover, a dispersion of an isotropic concentrated solution of complex salts is formed at higher temperatures in a reversible process. In summary, this study proves the importance of the polyion structure for tuning the properties of systems of complex salts.

Microstructure and corrosion behavior of die-cast AM60B magnesium alloys in a complex salt solution: A slow positron beam study

The microstructure and corrosion behavior of high pressure die-cast (HPDC) and super vacuum die-cast (SVDC) AM60B magnesium alloys were investigated in a complex salt solution using slow positron beam technique and potentiodynamic polarization tests. The experiments revealed that a CaCO3 film was formed on the surface of the alloys and that the rate of CaCO3 formation for the SVDC alloy with immersion time was slower than that of the HPDC alloy. The larger volume fraction of β-phase in the skin layer of the SVDC alloy than that of the HPDC alloy was responsible for the better corrosion resistance.

Reverse micelles with spines: L2phases of surfactant ion—polyion complex salts, n-alcohols and water investigated by rheology, NMR diffusion and SAXS measurements

Homogeneous alcoholic isotropic solutions (L2 phases) of “complex salts” of hexadecyltrimethylammonium neutralized by polyacrylate CTAPAn (n = 30 or 6000), in the presence of water were examined at 25 °C by means of small-angle X-ray scattering (SAXS), rheology and NMR self-diffusion measurements for different n-alcohols (octanol, hexanol and butanol) and at varying water contents. The greater water solubility and the slower water self-diffusion coefficients in these L2 phases, when compared to results with surfactant-free alcohols, suggested that these phases are composed of reverse aggregates with water in their cores. A comparatively rapid self-diffusion of the surfactant ion in butanol suggested a significant fraction of “free” surfactant ions, dissociated from the reverse aggregates. Rheological data confirmed that the obtained viscoelastic properties were consistent with a system containing entangled elongated micelles, whose properties were controlled by the polyion chain length. NMR diffusion measurements for complex salt solutions with the shorter counter-polyion (CTAPA30) produced estimates of the aggregate lengths that were close to the extended length of one PA30 chain. In summary, these results support the formation of aggregates composed by surfactant decorated polyion chains with a water core, whose properties are determined by the polyion chain length, behaving like reverse micelles with spines.

The thermochemical properties of transition metal complex salts with 1,5-diaminotetrazole

A method for determining the enthalpies of formation of coordination compounds of Cu(II), Co(II), Zn, and Cd perchlorates was developed. The enthalpies of solution of complex salts in water were measured. The enthalpy of combustion of the 1,5-diaminotetrazole ligand was determined, and the enthalpy of its formation in the standard state calculated. The experimental data were used to calculate the enthalpies of formation of the coordination compounds studied in the standard state.

Precipitation of metals by metals (cementation)—kinetics, equilibria

The generally accepted equation for describing the kinetics of the cementation process has been derived under several simplifying assumptions. Consequently, it does not explain some experimental facts and sometimes even leads to conclusions contradicted by the experiments. The main assumption is that the kinetics of the cementation is determined by the rate of transport of the metal A ions to be precipitated to the surface of the precipitating metal B. It does not explain why the rate of cementation of A, by a different metal B, differ from each other. It also does not explain why maxima appears on the potential ε A/B= f( t) curves. In the case of cementation from complex salt solutions, the assumption that the cementation runs to the point of zero concentration of A is oversimplified. Doubtful also is the assumption that the reaction surface, identified usually with that of the precipitating metal B, does not change with the progress of reaction. Problems of the direct determination of the cementation rate cause that, as a rule, the basic differential equation is not used but instead its secondary integral form is confronted with the experimental results. Therefore, an attempt has been made to perform cementation in a model cell. This enables determination of the rate of the process and also the potential ε A/B as a function of time. Results of these experiments have proved that the rate of the process does not diminish continuously, as follows from the differential equations. It rises initially and then decreases. The same concerns the ε A/B= f( t) dependence. Hypothetical runs of the polarization curves have been presented which explain these effects. They also help to explain why the cementation rates of the same metal A by various metal B may differ from each other. Reduction of AgCl has been also performed in the cementation model cell. Results of these experiments have helped to formulate some conclusions on the mechanism of that process. A method of Ag recovery from AgCl, presenting several advantages over that at present applied in industry, has been patented. This text presents a synthesis of results of several years of research.

IR-Spectroscopy Investigation of the Properties of Ionites in Uranium Sorption during Processing of Silicon-Containing Solutions and Pulps

IR spectroscopy was used to identify and study the structure and properties of domestic and foreign samples of ionites synthesized for the nuclear industry. The mechanism of uranium absorption from complex salt solutions and the interaction of uranium with functional groups of ionites were investigated. The changes in the structural and chemical properties of ionites subjected to prolonged commercial use were estimated. The dependence of the process of uranium sorption on anionites and the dynamics of accumulation of silicon compounds in the anionites were found. A comparative analysis of the data showed that the capability of an anionite to absorb silicon does not always interfere with uranium sorption. 6 figures, 2 tables, 9 references.

Acid-basic and sorption properties of modified polyvinyl alcohol fibre containing polyethylenepolyamine groups

The function of formation of copper(II) ion complexes was determined, and the distribution and separation coefficients of heavy metal ions were calculated in sorption from complex salt solutions. The selectivity of polyamine-containing PVA fibre with respect to copper(II) and lead(II) ions was determined in sorption from complex salt solutions. It was found that the fibre exhibits sorption activity for platinum group metals.

Formation of the Perovskite Phase Pb3NiNb2O9

AbstractPb3NiSNb2O9 was synthesized via various methods in order to investigate the mechanisms of perovskite formation. Two relatively simple routes to precursors that give single‐phase perovskite after calcination at 900°C are described: a modified columbite‐method and a synthesis from a freezedried complex salt solution. The results show that the formation of perovskite Pb3NiNb2O9 does not start below 900 °C and that the pyrochlore formation beginning at lower temperatures has be hindered by a thermal shock calcination.

Fundamental aspects of plating technology III: The effect of electrodeposition from complex salt solutions on metal distribution over macroprofiles

It is shown that the improved metal distribution over the macroprofiles of electrodeposits obtained from ammonium complex salt solutions compared with deposits obtained from nitrate salt solutions is due to the decrease in the exchange current density for the deposition process.

Fundamental aspects of plating technology II: Morphological aspects of metal electrodeposition from complex salt solutions

It is shown that the improved quality of electrodeposits obtained from ammonium complex salt solutions compared with deposits obtained from simple salt solutions is due to the decrease in the exchange current density value for the deposition process.

Stabilities of 7, 7, 8, 8-Tetracyanoquinodimethane Salts of Polycation Polymers

The correlations between the stabilities of 7, 7, 8, 8-tetracyanoquinodimethane (CQ) salts of polycation polymers and their electric conductivities were studied to elucidate the decomposition reaction of CQ salts. The specific resistance (P) of polycation-CQ salts changed as follows in an air: p: CQ simple salt>CQ complex salt Solution>Solid state. The results of electronic spectra showed that the stabilities of CQ salts related to the decomposition of CQ anion radical (CQ') and to that due to water. On the basis of the chemical analyses of the isolated decomposition products, CQ was found to change into ce, a'-dicyano-p(cyanocarbony1)-a-toluenide (DCT-). As a result of the decomposition of CQ, the electric conductivities of polycation-CQ salts decreased not only with losing unpaired electrons, carrier of electricity, but also with disintegrating conduction paths.

Asthma due to inhaled chemical agents--complex salts of platinum.

SummarySixteen workers, from a platinum refinery, with respiratory disease were tested with solutions of complex salts of platinum and ten gave immediate prick test reactions to concentrations of 10−4−10−6and immediate nasal reactions in seven out of eleven tested to concentrations of 103−10−8. Occupational‐type exposure inhalation tests to the dust from mixtures of 40 mg of the platinum salt with 1 kg of lactose gave immediate asthmatic reactions in eight and in one of these a late reaction, all also giving immediate prick test reactions. The asthmatic reactions were inhibited by disodium cromoglycate. In two with negative prick tests, late asthmatic reactions were elicited. The occupational‐type exposure test provides a safe, acceptable procedure for etiological diagnosis.

Salt Dependency of the Bacterial Flora of Marine Fish

SUMMARY: The bacterial flora on the skin of plaice (Kareius bicoloratus) caught in coastal regions of Japan was composed of bacterial groups heterogenous to the concentration of salt in their growth behaviour. Each bacterial group had a different minimum and/or maximum salt concentration for growth, and different groups were selected by media with different salt concentration. In the media based on two complex salt solutions, including an artificial sea water, the maximum bacterial counts were obtained at concentrations corresponding to about 25% dilution of sea water. During the storage of fish at 24° and 2°, bacteria which required higher salt concentrations for growth increased faster than that of non-halophilic bacteria. The microflora of the digestive tract of the fish was composed almost exclusively of halophilic vibrios.

銅-クエン酸錯塩電解浴について

The reaction of the formation of complex salt between cupric and citrate ions was investigated with spectrophotometer. It was found that stable cupric citrate was formed in the range of pH 5.5-12.0, and its dissociation constant was 7.80×10-6 at pH 7.0.By the application of the above complex salt solution to the electroplating bath for copper, adherent and lustrous deposit of copper was obtained on steel.The composition of the electrolyte and the conditions of electrolysis are as follows.Cupric sulfate 0.5mol/lSodium citrate 1.0mol/lpH 4.0-5.0Temperature 40-50°CCathode current density 0.3-0.8A/dm2

‘Total’ Ionic Consideration of Aqueous Systems in Biology

AGRONOMISTS and agricultural chemists in practice condone statements about applying a given weight ‘of P2O5’; the only certainty then is that phosphorus pentoxide was not used, though a reader may infer that an unspecified phosphate is meant, either alone or mixed with much calcium sulphate. Statements, common in physiological literature, about treating a patient or a tissue with ‘potassium’ or ‘Mg++’ are little more exact or informative for a research student or historian; nor are terms like ‘ion-balance’, or discussions of ‘ions’, when restricted to cations. Phenomena observed in solutions of complex salts are commonly attributed to ‘effects of pH’; series of solutions ‘adjusted to various pH-values’, ‘lacking NO3’, ‘having extra Na’, etc., are taken to be comparable, except for what is thought to be a single ionic variable.