Effect Of Inorganic Salts Research Articles

Photochemical Transformation of Ibuprofen and Chlorophene Induced by Dissolved Organic Matter.

Both ibuprofen (IBP) and chlorophene (CP) are frequently detected contaminants in surface aqueous environment. Dissolved organic matter (DOM) is an important component in water with high photo-reactivity, playing an important role in the transformation processes of various organic pollutants. This study systematically studied the influence of DOM on the photochemical transformation of IBP and CP by using humic acid as model DOM. In addition, the effect of inorganic salts on this process is also considered due to the high salt content in the ocean. Further quenching experiments and reactive oxygen species (ROSs) detection were also conducted to explore the reactive species acting on the IBP and CP transformation. Based on the products analysis and theoretical calculation, we proposed the IBP and CP transformation mechanism. Overall, this study provides some new insights into the transformation of organic pollutants in natural surface water, which is significant for assessing the fate of pollutants.

Preparation of Thermal Controlled Deoxygenation Inhibitor and Its Inhibition of Coal Spontaneous Combustion

ABSTRACT The purpose of this study was to prepare a new type of thermal controlled deoxygenation inhibitor successfully. By adding a particular inorganic salt hydrate, this new deoxidizing inhibitor effectively slows down the oxidative-exothermic reaction that may occur during the action of the original deoxidizing inhibitor, improving the efficiency of preventing coal from spontaneous combustion. The heat shielding approach was employed, using the inorganic salt hydrate’s high heat capacity to absorb and decelerate heat transport during the phase change process. To assess the heat shielding effect of inorganic salt hydrates like Na2CO3·10 H2O, MgSO4·7 H2O, Na2SO4·10 H2O, MgCl2·6 H2O, and CaCl2·6 H2O, we conducted tests using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). With a heat shielding effect of 171.2 J/g, which is much superior to that of other hydrates, the testing results demonstrate that Na2CO3·10 H2O has the best thermal control performance. In addition, we verified the effective inhibition of coal spontaneous combustion by the thermal controlled deoxygenation inhibitor, especially under the condition of increasing temperature, and the blocking effect of the inhibitor was enhanced with the increase of temperature. The findings of this study provide a new strategy for spontaneous combustion prevention during coal mining and storage and provide a scientific basis for further industrial application and optimization.

Study on the effects of inorganic salts and ionic surfactants on the wettability of coal based on the experimental and molecular dynamics investigations

Through the evaluation and preparation of a novel inorganic salt composite solution consisting of sodium dodecyl benzene sulfonate (SDBS), the nonionic surfactants polyethylene glycol pisooctyl phenyl ether (Triton X-100), and inorganic salt Na2SO4, based on surface tension, contact angle, settling time, wetting rate, and changes in the surface microstructure and functional groups of coal, this study analyzed the wetting behavior of the solution on coal dust and its adsorption capacity on the surface of coal particles. The results demonstrate that the composite solution of inorganic salts can significantly enhance the wettability of coal samples, reducing the contact angle to 21.54° and lowering the surface tension to 26.10 mN/m. After treatment with the solution, the relative content of oxygen-containing functional groups in the microscopic structure of the coal sample increased to 59.6 % and pores more prominent than 25 nm increased to 34.63 %. Molecular dynamics (MD) simulations of the water-inorganic salt composite solution-coal system are conducted using Materials Studio software, revealing that after the addition of the composite solution, the self-diffusion coefficient (D) of water molecules is 6.3 × 10-9 m2/s, the starting point of the composite solution is 15 Å, and the system's interaction energy increase to 14000 kcal/mol. It further elucidated the modification of the surface molecular structure of coal dust by the inorganic salt composite solution, increasing hydrogen bonds, enhancing wetting, and demonstrating a solid adsorption capability of the inorganic salt composite solution on the surface of coal dust.

Effects of Inorganic Salts on the Phase Separation of Partially Miscible Solutes.

Partially miscible solutions with a lower critical solution temperature have promising applications in the field of physical chemistry. To better guide the utilization of these solutions in practice, we conduct an in-depth study about the phase separation behavior of the solution added with inorganic salts. The addition of the inorganic salts into the solution is found to consequently reduce the phase separation temperature. The variation of concentrations of inorganic salts does not notably affect the mass fraction of the separation. Moreover, the addition of inorganic salts in the solutions at lower mass fractions improves the separation mass fraction, while the addition of inorganic salts decreases the separation mass fraction at the mass fractions above 30%. It sheds light on selecting the proper mass fractions and inorganic salt concentrations. Furthermore, we explore the phase separation behavior of mixed solutions under different inorganic salt additions by means of a high-speed camera. The phase separation behavior under different inorganic salt systems shows a similar trend. However, calcium ions and Fe3+ ions in the solutions can greatly decrease the rate of droplet coalescence and result in an increase in phase separation. For better regulating the solutions with a lower critical solution temperature through inorganic salts, sodium chloride or potassium chloride is recommended with an appropriate concentration.

Effect of inorganic salts / lignin on the combustion performance of torrefied biochar

In this study, inorganic salts (KMnO4, Ba(NO3)2) and enzymolysis lignin were added into torrefied biochar to improve the drawback of high ignition temperature during combustion when biomass underwent torrefaction. Weight loss characteristics, gas products, combustion kinetics of torrefied biochar with different additives were investigated. The addition of KMnO4, Ba(NO3)2, enzymolysis lignin, and their blends can reduce the ignition point of torrefied biochar, and the addition of Ba(NO3)2 can also extent the burnout time. When KMnO4, Ba(NO3)2 and lignin were added at the same time, the first weight loss peak temperature was reduced, and the reaction rate was accelerated. The combustion kinetics of torrefied biochar with different inorganic salts/lignin can be described by a simple first-order reaction. The addition of different inorganic salts/lignin additives is beneficial to reduce the activation energy of the low temperature reaction stage, and the activation energy of torrefied biochar with lignin addition decreases the most.

Molecular dynamics study on the effect of inorganic salts on the wettability of surfactants on bituminous coal: Sodium dodecyl sulfate and sodium chloride as representatives

To further enhance the wetting ability of surfactants to coal, the mechanism of improving the wetting performance of SDS to bituminous coal by the addition of inorganic salt NaCl was studied through a combination of molecular dynamics (MD) simulation with experimental measurements. In the experiment part, the surface tensions of the mixed NaCl-SDS solutions and the contact angles on the bituminous coal surface were measured. Furthermore, MD simulations were conducted to investigate the adsorption characteristics and wetting mechanism of a mixed NaCl-SDS solution on the coal surface at the atomic scale. In this process, the static potentials of the H2O molecule, coal molecule and SDS molecule were calculated, and the number of hydrogen bonds (H-bonds) formed throughout the whole simulation process, the average H-bond length, the relative concentration distribution (RCD) curve and the mean square displacement (MSD) curve were obtained. The experimental results showed that the surface tension and contact angle were both decreased by the addition of sodium chloride in mixed solutions. When 0.6 mol/L NaCl was added, the surface tension and contact angle reached the minima of 30.45 mN/m and 13.01°, respectively. The MD simulation results showed that, after the addition of NaCl, diffusion and migration of H2O molecules were limited, the number of H-bonds increases, the average bond length decreased, the sorption between H2O molecules and coal molecules was enhanced, and the hydrophilicity of coal surface was improved, which meant that the wetting ability of SDS solution to bituminous coal was enhanced by adding NaCl. The effect of the added NaCl in improving the wettability of SDS on coal was explored from two perspectives with macroscopic experiments and microcosmic simulations, and the added NaCl improved the effects of dust suppressants, and played a key role in preventing dust hazards in coal mines.

Thermal Characteristics of Selected Phosphate Ores and the Effect of Inorganic Salts on Their Calcination

Thermal Characteristics of Selected Phosphate Ores and the Effect of Inorganic Salts on Their Calcination

Solvophobic effects in the mixtures of inorganic salts and organic solvents

The effect of inorganic salts on the solvation properties of organic solvents is analyzed. Experimental data on the thermodynamic functions of solvation at 298.15 K for alkanes and aromatic hydrocarbons in methanol and tetrahydrofuran at varying concentrations of sodium iodide or lithium bromide have been obtained. The solubility of apolar compounds decreases with growing salt concentration as the Gibbs free energy of solvation linearly increases with the salt molarity. Hence, the salt effects in non-aqueous solvents can be characterized with Sechenov constants like those in aqueous solutions. An increase in salt concentration leads to a decrease in the entropy of hydrocarbon solvation. Calculation of the thermodynamic functions of cavity formation in the studied systems based on the molecular dynamics data show that the salt effects can be attributed to a less favorable and lower-entropy cavity formation. The Gibbs free energy of cavity formation is also linear on the salt concentration. These results can be interpreted as strengthening of the solvophobic effects upon salt addition, similar to what is typical for aqueous solutions. The observed trends are also similar to the behavior of solvation free energies in ionic liquids, which are known to correlate with ion concentration.

Effect of inorganic salts in coal seams on the sand-carrying capacity of hydroxypropyl guar foam-fracturing fluid: An experimental study

Coal seam water typically contains inorganic salts, which could affect the sand-carrying capacity of foam-fracturing fluid. This study selected the standard cationic surfactant cetyltrimethylammonium bromide as the foaming agent, used the high molecular polymer hydroxypropyl guar gum as the foam stabilizer to prepare foam-fracturing fluid, and selected silica particles as the proppant. The effects of different CaCl2, NaHCO3, MgSO4, and KCl concentrations on sand-carrying sedimentation of foam-fracturing fluid were evaluated. The effects of inorganic salts on foam morphology and foam morphology on proppant sedimentation were obtained through microscope observation, and the mechanism of inorganic salts on proppant sedimentation in foam-fracturing fluids was explored. The results show that 1% CaCl2 and 0.1% NaHCO3 inhibited the sand-carrying capacity of the foam-fracturing fluid, whereas two concentrations of MgSO4 and KCl promote the sand-carrying capacity of the foam-fracturing fluid. The effect of inorganic salts on the sand-carrying properties of cationic surfactant foam-fracturing fluids is divided into two main stages. During the settling phase, inorganic salts affect settling by changing the viscosity of the foam-fracturing fluid and the repulsive force of the double electric layer on the proppant. During the suspension phase, the proppant improves the probability of collision between the proppant and the foam by promoting the foam particle size and improves the hindering effect of foam pressure and structural forces on the proppant. The results have a guiding significance for developing foam-fracturing technology.

Synergistic effect of inorganic salt and AlN removal in the secondary aluminum dross during the roasting process

This study investigated the synergistic transformations and interaction effects of inorganic salts with high-content (HS-SAD) and low-content (LS-SAD) and AlN in secondary aluminum dross (SAD) during the roasting process. The results demonstrated that the presence of inorganic salts significantly enhanced the oxidation of AlN in SAD. The removal efficiency of AlN in HS-SAD reached 95.8 % at 800 °C for 120 min, whereas in LS-SAD, it was 69.47 % at 1000 °C. The oxidation of AlN leads to the formation of a 25–45 nm alumina film, which hinders the further progression of the oxidation process. The presence of SO2 and SiO2 facilitated the low-temperature volatilization of inorganic salts, thereby limiting the formation of the alumina film. The partial melting of inorganic salts and the reaction of NaF with the alumina film, resulting in the formation of Na2O, destroyed the dense alumina film, exposing AlN. Following roasting at 800 °C and 1000 °C, the hazardous components in both HS-SAD and LS-SAD were effectively eliminated, and 92.93 % of the inorganic salts in HS-SAD were successfully recovered. Roasting at a mixing ratio of 1:1 at 900 °C for 120 min resulted in an 86.97 % removal efficiency of AlN. These findings offer valuable insights into the removal of AlN in SAD and the comprehensive utilization of SAD residue.

An EIS study of the effects of inorganic salts in the adsorption of flotation reagents on galena

An EIS study of the effects of inorganic salts in the adsorption of flotation reagents on galena

Influence of V-containing species on formation and corrosion resistance of PEO coatings developed on AZ31B Mg alloy

The defects, micropores, and microcracks on the plasma electrolytic oxidation (PEO) coating severely affect the long-term anti-corrosion feature. Inclusion of additives in the electrolyte is a feasible and effective strategy to attain the more intact PEO coating. The PEO coatings are fabricated on AZ31B Mg alloys in an silicon-based electrolyte with Na3VO4 (OPEO), NaVO3 (MPEO), and V2O3 (VPEO), respectively, to explore the influence of additives on the corrosion resistance. MPEO sample has the smallest poriness and pore size unfolding the best anti-corrosion resistance, which is also consistent with the electrochemical analysis. Even after 336 h salt spray test, the MPEO coating exhibits the least corrosion. The excellent anti-corrosion performance of MPEO sample is the synergistic effect of inorganic salts and multiple metal oxides generated in the formation of PEO coating. Inclusion of inorganic salt with valence change metal is a feasible pathway to achieve the compact PEO coating since multiple metal oxides could be produced and deposited in the PEO coating during the fabrication.

Toughening Double Network Hydrogels by Polyelectrolytes.

Hoffmeister effect of inorganic salts has been verified as a promising way to toughen hydrogels, however, the high concentration of inorganic salts may accompany by poor biocompatibility. In this work, for the first time, we find that polyelectrolytes can obviously elevate the mechanical performances of hydrogels through Hoffmeister effect. The introduction of anionic poly(sodium acrylate) (P(iAA)) into poly(vinyl alcohol) (PVA) hydrogel induces the aggregation and crystallization of PVA to boost the mechanical properties of the resulting double network hydrogel: elevation of 73, 64, 28, 135, and 19 times in the tensile strength, compressive strength, Young's modulus, toughness, and fracture energy compared with poly(acrylic acid) (PAA), respectively. It is noteworthy that the mechanical performances of the hydrogels can be flexibly tuned by the variation of polyelectrolyte concentration, ionization degree, relative hydrophobicity of the ionic component and polyelectrolyte type in a wide range. This strategy is verified to work for other Hoffmeister effect-sensitive polymers and polyelectrolytes. Also, the introduction of urea bonds into polyelectrolytes can further improve the mechanical properties and anti-swelling capability of hydrogels. As a biomedical patch, the advanced hydrogel can efficiently inhibit hernia formation and promote the regeneration of soft tissues in abdominal wall defect model. This article is protected by copyright. All rights reserved.

The effect of inorganic salt on the morphology and nucleation of polyaniline nanofibers synthesized via self-assembly

ABSTRACTPolyaniline (PANI), due to the various and controllable shapes, the environmental stability, the excellent physical and chemical property, has gained significant attention. PANI with abundant morphologies were successfully prepared through adjusting and controlling the state of the initial micelle-like in the micelle-like system composed by aniline and organic acids with relatively weak intermolecular interaction. Although the influence of the inorganic salts on their morphology, including the surface and the diameter, was investigated, the influence of salt on the nucleation of PANI was still unclear. Therefore, PANI nanofibers were fabricated through the addition of inorganic salt such as NaCl, MgSO4 and AlCl3 into the micelle-like composed of aniline and D-camphor-10-sulfonic acid. The influence of types and concentration of inorganic salts, doped acids and temperature on PANI was studied by Transmission Electron Microscope (TEM), UV-vis and Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy. In addition, in situ UV-vis and 1H Nuclear Magnetic Resonance technology (NMR) were applied to observe the process of aniline polymerization, and it was indicated the polymerization rate of aniline changed after the addition of inorganic salt NaCl into the initial solution.

Effect of inorganic salt on the thermal degradation of nitrocellulose and reaction mechanism of its mixture

In this study, to better understand the reaction mechanism between inorganic salts and nitrocellulose, CaCO3 and Li2CO3 were evaluated with respect to their effects on the thermal degradation of NC in nitrogen atmosphere using TG/DSC at three different heating rates (2, 5, 10 K/min). The numerical relationship between activation energy (E) and conversion rate was obtained by FWO and KAS method, and it was discovered that CaCO3 could improve the thermal stability of NC. Activation energy values were calculated by Kissinger method, and it was found that NC that contain Li2CO3 had the highest activation energy while NC containing CaCO3 had the lowest E value. By combining the thermal analysis data with Malek method, the most probable mechanism model of thermal degradation is obtained as Šesták-Berggren model, which expression is f(α) = αm (1 - α)n. As a result of this study, there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.

Experimental Study of the Influence of Inorganic Salts on Foam Stability

The aqueous film-forming foam (AFFF) extinguishing agent is suitable for fighting various hydrocarbon fuel fires due to its dual fire-fighting effect of foam and liquid film. Because the action law and microscopic mechanism of inorganic salts on the stabilization process of surfactant-generated AFFF are not perfect, this paper employs an experimental approach to investigate the effects of inorganic salt types and concentrations on sodium dodecyl sulfate-containing foam systems (SDS). Prior to critical micelle concentration (CMC), increasing inorganic salt concentration decreased solution surface tension, but the opposite was true after CMC. The CMC value of an SDS solution decreases as inorganic salt concentration increases, and the "salting effect" of inorganic salt cations also has an effect on the CMC value. Based on the resistance of the liquid film at the gas-liquid interface affecting gas transport, the foam evolution was divided into three stages: foam generation, liquid drainage, and gas transfer. The effect of inorganic salts on these three stages was studied at the molecular level, and it was discovered that the addition of NH4Cl and MgCl2 could improve the saturation adsorption at the gas-liquid interface, reduce the surface tension of the surfactant solution, and improve foam stability. Meanwhile, inorganic salts can change the force of gas molecules, so the equilibrium force of gas across the liquid membrane increases as inorganic salt concentration increases. Additionally, the addition of inorganic salts raises the diffusive drainage coefficient, but the gravity drainage coefficient still reigns supreme in the predecay period.

Effect of inorganic salt on the removal of typical pollutants in wastewater by RuO2/TiO2 via catalytic wet air oxidation

The treatment of high-salinity and high-organic wastewater is a tough task, with the removal of organic matter and the separation of salts often mutually restricting. Catalytic wet air oxidation (CWAO) coupled desalination technology (membrane distillation (MD), membrane bioreactor (MBR), ultrafiltration (UF), nanofiltration (NF), etc.) provides an effective method to simultaneously degrade the high-salinity (via desalination) and high-organic matters (via CWAO) in wastewater. In this work, five kinds of RuO2/TiO2 catalysts with different calcination temperatures were prepared for CWAO of maleic acid wastewater with a theoretical chemical oxygen demand (COD) value of 20,000 mg L−1. RuO2/TiO2 series catalysts demonstrated prominent salt resistance, with more than 80% TOC removal rates in the CWAO system containing 5 wt% Na2SO4; while RuO2/TiO2-350 showed the best degradation performance in both non-salinity and Na2SO4-containing conditions. Multiple characterization techniques, such as XRD, BET, XPS, NH3-TPD and TEM etc., verified the physicochemical structure of RuO2/TiO2 catalysts, and their influence on the degradation of pollutants. The calcination temperature was found to have a direct impact on the specific surface area, pore volume, oxygen vacancies and acid sites of catalysts, which in turn affected the ultimate catalytic activity. Furthermore, we also investigated the performance of the RuO2/TiO2-350 catalyst for the treatment of acids, alcohols and aromatic compounds with the addition of NaCl or Na2SO4, proving its good universality and excellent salt resistance in saline wastewater. Meanwhile, the relationship between the structure of three types of organic compounds and the degradation effect in the CWAO system was also explored.

Performance evaluation of passive alkaline direct methanol fuel cell-the effect of inorganic salt and TiO2 nano fillers

In order to address the shortcomings of proton exchange membrane operating in an acidic medium and anion exchange membrane using in an alkaline medium, the present study investigated the synthesis of polyvinyl alcohol-based sodium ion conducting membrane working in an alkaline medium for the direct methanol fuel cell. The merits of the alkaline medium and cation exchange membrane are exploited by the sodium ion conducting membrane developed for alkaline direct methanol fuel cells. Poly vinyl alcohol -titanium dioxide sodium ion conducting membrane is prepared by modified phase inversion technique using the salt solution as the non-solvent in the coagulation bath. The ionic conductivity, methanol permeability, and V-I characteristics of the cation exchange membrane were studied under ambient conditions. The performance of the poly vinyl alcohol -titanium dioxide membrane is studied in a passive direct methanol fuel cell, and it is compared with the Nafion 117/Na+ membrane and poly vinyl alcohol-based anion exchange membrane. Single cell assembly with poly vinyl alcohol -titanium dioxide membrane showed a 17.14 % increase in the power density as compared to Nafion 117/Na+ membrane and a 72.77 % increase as compared to poly vinyl alcohol-based anion exchange membrane operating in the alkaline environment under ambient conditions.

Study of Salting Effect of Inorganic Salts on Nano- and Giant Polymersomes

Study of Salting Effect of Inorganic Salts on Nano- and Giant Polymersomes

Performance Evaluation and Mechanism Study of Seawater-Based Circulatory Fracturing Fluid Based on pH-Regulated WormLike Micelles.

In this article, a novel salt-resistant pH-sensitive surfactant N-carboxystearamido methanesulfonic acid (MSA) was designed and synthesized. The rheological properties of the MSA/CTAB mixed system prepared using seawater were evaluated, and the variation laws of the related rheological parameters were discussed. The relevant fracturing technical parameters of the MSA/CTAB mixed system were comprehensively evaluated. The wormlike micelles formed by the non-covalent binding of MSA and CTAB molecules can resist the electrostatic effect of inorganic salts in the seawater. Meanwhile, the MSA/CTAB mixed system has an excellent pH response and revealed that the change from wormlike micelles to spherical micelles leads to the decrease of the apparent viscosity and the transition from Maxwell fluid to Newton-type fluid. Furthermore, the MSA/CTAB mixed system has excellent cyclic fracturing performance, which can meet the dual requirements of fracturing fluid cost and performance of offshore oilfield, and has a good application prospect.