NaNO3 System Research Articles

Kinetic Mass Transfer Behavior of Eu(III) in Nitrilotriacetamide-Impregnated Polymer-Coated Silica Particles

Abstract We investigated the distribution mechanism of Eu(III) in a single polymer-coated silica particle including nitrilotriacetamide (NTA) extractants known as HONTA and TOD2EHNTA. We studied the kinetic rate constants of the distribution process at various concentrations of NO3− (CNO3−) that were prepared using HNO3 and NaNO3 solutions. The rate-determining process during the distribution of Eu(III) was identified as the reaction process of Eu(III) for both extractants, that is, the reaction process of Eu(III) and two NTA molecules in the polymer layer of the silica particle. Furthermore, the reaction of Eu(III) with NO3− ions was found not to be involved in the rate-determining process. The forward (k1) and backward (k−1) reaction kinetic constants for the reaction between Eu(III) and two NTA molecules were determined to be k1 = (5.7 ± 2.2) × 102 M−2 s−1 and k−1 = (2.3 ± 4.4) × 10−4 s−1 for HONTA, and k1 = (6.5 ± 3.0) × 102 M−2 s−1 in the NaNO3 system and k−1 = (2.0 ± 1.5) × 10−4 s−1 in both solutions for TOD2EHNTA. The present study provides a valuable approach for the evaluation and enhancement of the functionality of ‘single extractant-impregnated polymer-coated silica particles’.

Development of New Targeted Nanotherapy Combined with Magneto-Fluorescent Nanoparticles against Colorectal Cancer.

The need for non-invasive therapies capable of conserving drug efficiency and stability while having specific targetability against colorectal cancer (CRC), has made nanoparticles preferable vehicles and principal building blocks for the development of complex and multi-action anti-tumoral approaches. For that purpose, we herein report the production of a combinatory anti-tumoral nanotherapy using the production of a new targeting towards CRC lines. To do so, Magneto-fluorescent NANO3 nanoparticles were used as nanocarriers for a combination of the drugs doxorubicin (DOX) and ofloxacin (OFLO). NANO3 nanoparticles' surface was modified with two different targeting agents, a newly synthesized (anti-CA IX acetazolamide derivative (AZM-SH)) and a commercially available (anti-epidermal growth factor receptor (EGFR), Cetuximab). The cytotoxicity revealed that only DOX-containing nanosystems showed significant and even competitive cytotoxicity when compared to that of free DOX. Interestingly, surface modification with AZM-SH promoted an increased cellular uptake in the HCT116 cell line, surpassing even those functionalized with Cetuximab. The results show that the new target has high potential to be used as a nanotherapy agent for CRC cells, surpassing commercial targets. As a proof-of-concept, an oral administration form of NANO3 systems was successfully combined with Eudragit® enteric coating and studied under extreme conditions.

Thermodynamics of the Ca(NO3)2 – NaNO3 system

Thermodynamic properties of the quasi binary Ca(NO3)2–NaNO3 system are of interest with respect to thermal energy storage. In the present work the phase diagram as well as thermodynamic properties of the near eutectic mixture 45 mol% Ca(NO3)2 – 55 mol% (NaNO3)2 were determined experimentally and applied in the assessment of a new Gibbs energy dataset for thermochemical calculations. The enthalpy of fusion of the 45 mol% Ca(NO3)2 – 55 mol% (NaNO3)2 mixture is determined to be 24.7 ± 0.5 kJ/mol. The melting and crystallization enthalpy have good reproducibility, which makes it possible to use this mixture as a phase change material at temperature 225 °C. The assessed dataset describes liquid phase properties using a subregular solution model in the Redlich-Kister formalism with high accuracy. Therefore it can be used for the prediction of thermodynamic properties of different compositions in the whole Ca(NO3)2–NaNO3 system and be included in databases for calculation of multicomponent systems including other components.

Study on MNO3/NO2 (M = Li, Na, and K)/MgO Composites for Intermediate-Temperature CO2 Capture

Molten salt [MNO3/NO2 (M = Li, Na, and K)]-promoted MgO composite-type CO2 adsorbents with high capacity and cycling stability are fabricated by controlled hydrolysis along with an incipient impregnation approach. The remarkable results of molten salts on the CO2 capture performance of MgO adsorbents and the CO2 capture capacities with different loadings and calcination and adsorption temperatures were comprehensively investigated. Notably, optimized NaNO3-promoted MgO exhibited the highest CO2 capture capacity of 17.0 mmol g–1 at 350 °C and maintained excellent regenerability through multiple cycles. The initial CO2 uptakes of MNO3/NO2 (M = Li, Na, and K)/MgO composites follow the order of NaNO3 (17.0 mmol g–1) > LiNO3 (14.1 mmol g–1) > NaNO2 (12.5 mmol g–1) > KNO2 (9.3 mmol g–1) > KNO3 (5.0 mmol g–1). Furthermore, NaNO3 and KNO3 with good chemical stability are the effective constituents for the NaNO3 system and KNO3/KNO2-promoted system, respectively, and preserved their original form after the interac...

Significant enhancement in treatment of salty wastewater by pre-magnetization Fe0/H2O2 process

Nowadays, Fenton (Fe2+/H2O2) process is increasingly applied to wastewater treatment, however, the treatment efficiency would be inhibited largely when treated salty wastewater. To overcome this limitation, pre-magnetization (pre-magn-Fe0)/H2O2 process was investigated to treat salty wastewater, which could enhance the degradation rate of organic pollutants (1.2–171.2 folds enhancement) and reduce reagents dosage (save 75% H2O2) in salty system compared with Fe0/H2O2 process, using Orange G as the target pollutant and Na2SO4 as the model salty system. The characterizations by SEM, XRD and XPS and the intensity of DMPO–OH adduct signals in different processes confirmed this enhancement attributed to the increase of corrosion of Fe0 inducing fast catalysis of H2O2 and generation of hydroxyl radicals. Pre-magn-Fe0/H2O2 process could also have 5.9, 26.4 and 93.7 folds enhancement in NaCl, NaNO3 and Na2HPO4 salty system, respectively. Meanwhile, pre-magn-Fe0/H2O2 process could keep close performance in Na2SO4 and NaCl salty systems and have better performance in NaNO3 and Na2HPO4 salty systems than Fenton process. Pre-magn-Fe0/H2O2 process also had remarkable improvement (1.1–5.3 folds) on the removal of many refractory contaminants in salty system. Furthermore, it could also keep good performance in real reverse osmosis concentrated wastewater and petrochemical wastewater. Therefore, pre-magn-Fe0/H2O2 process is a more cost-effective process to treat salty wastewater, which could have not only improved performance than conventional system and Fe0/H2O2 process, but also good performance as Fenton process.

Molecular Dynamics Simulations of the Thermal and Transport Properties of Molten NaNO<sub>2</sub>–NaNO<sub>3</sub> Systems

The thermodynamic and transport properties of nitrite and nitrate salts, which are candidates for thermal energy storage, were investigated by differential scanning calorimetry (DSC), high-temperature pulse-field NMR, and molecular dynamics (MD) simulations. The potential parameters of NO2 for the MD simulations were newly developed by ab initio calculations and empirical approaches. The MD results for molten xNaNO2–(1 − x)NaNO3 salts (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were comparable to the experimental density and Na self-diffusion coefficients. Moreover, the temperature-averaged heat capacities of the molten xNaNO2–(1 − x)NaNO3 systems were calculated from the changes in the energy and volume versus the temperature, which reproduced the results obtained from the DSC measurements well.

Electronic Polarisability of NaNO2–NaNO3 and NaOH–NaNO3 Ionic Melts and Effective Ionic Radius of OH－

Abstract Molar volumes and refractive indexes of molten NaNO2–NaNO3 and NaOH–NaNO3 systems were measured by dilatometry and goniometry, respectively. The molar volumes of both systems increased with increasing temperature. Refractive indexes decreased with a rise of temperature or with increasing wavelength of the incident visible light. Assuming that the electronic polarisability is inherent in an ion, the electronic polarisability of a OH－ ion in the melt was estimated from the Lorentz–Lorenz equation to be 1.26×10−30 m3, being comparable with that in the crystal. The effective ionic radius of a OH－ ion was evaluated from the obtained electronic polarisability to be 1.34×10−10 m, using the correlation between the third power of the ionic radius and the electronic polarisability of an ion so far reported. The effective ionic radius obtained in this work was in good agreement with that assigned by Shannon.

Influence of anions on the structure and morphology of steel rust particles prepared by aerial oxidation of acidic Fe(II) solutions

In order to simulate the atmospheric corrosion of steel, artificial steel rust particles were synthesized by aerial oxidation of aqueous solutions containing FeCl2, FeSO4 and NaNO3, and the structure and morphology of the obtained particles were characterized by XRD and TEM. Needle-like SO42− containing Schwertmannite (Fe8O8(OH)6(SO4)) particles were mainly formed in FeCl2–FeSO4, FeSO4–NaNO3, FeCl2–FeSO4–NaNO3 systems, and the crystallization and particle growth of this material were not influenced by added Cl− and NO3−. The rod-shaped β-FeOOH particles were formed from in only FeCl3-NaNO3 system, though no marked change in crystallite and particle sizes of the β-FeOOH was recognized by adding NO3−. Accordingly, it can be suggested that the corrosive SOX gas and air-borne chloride strongly affect the rust formation in atmospheric corrosion of the steels.

Mechanochemical synthesis of colloidal silver bromide particles in the NaBr–AgNO3–NaNO3 system

X-ray diffraction and thermal analyses, electron microscopy, and dynamic light scattering have been employed to study silver bromide nanoparticles obtained by the mechanochemical exchange reaction NaBr + AgNO3 + zNaNO3 = (z + 1)NaNO3 + AgBr in sodium nitrate matrix (diluent and side reaction product) at z = z1 = 8.06 and z = z2 = 4.31. AgBr nanoparticles have been obtained in the free form by dissolving the matrix in water, and their activity in the photodegradation of methylene blue dye has been studied.

Impact of environmental conditions on aggregation kinetics of hematite and goethite nanoparticles

Hematite and goethite nanoparticles were used as model minerals to investigate their aggregation kinetics under soil environmental conditions in the present study. The hydrodynamic diameters of hematite and goethite nanoparticles were 34.4 and 66.3 nm, respectively. The positive surface charges and zeta potential values for goethite were higher than for hematite. The effective diameter for goethite was much larger than for hematite due to anisotropic sticking of needle-shaped goethite during aggregation. Moreover, the critical coagulation concentration (CCC) values of nanoparticles in solutions of NaNO3, NaCl, NaF, and Na2SO4 were 79.2, 75.0, 7.8, and 0.5 mM for hematite and they were 54.7, 62.6, 5.5, and 0.2 mM for goethite, respectively. The disparity of anions in inducing hematite or goethite aggregation lay in the differences in interfacial interactions. NO3 − and Cl− could decrease the zeta potential and enhance aggregation mainly through increasing ionic strength and compressing electric double layers of hematite and goethite nanoparticles. F− and SO4 2− highly destabilized the suspensions of nanoparticles mainly through specific adsorption and then neutralizing the positive surface charges of nanoparticles. Specific adsorption of cations could increase positive surface charges and stabilize hematite and goethite nanoparticles. The Hamaker constants of hematite and goethite nanoparticles were calculated to be 2.87 × 10−20 and 2.29 × 10−20 J−1, respectively. The predicted CCC values based on DLVO theory were consistent well with the experimentally determined CCC values in NaNO3, NaCl, NaF, and Na2SO4 systems, which demonstrated that DLVO theory could successfully predict the aggregation kinetics even when specific adsorption of ions occurred.

Thermodynamic modeling of the AgNO3–CsNO3–NaNO3 ternary system

By means of an optimization procedure, the AgNO3–CsNO3–NaNO3 ternary system has been assessed. The mixing enthalpies in the ternary system and the results derived from thermodynamic descriptions for the three limiting binary systems are used. For the AgNO3–NaNO3 and CsNO3–NaNO3 systems, optimized Gibbs energy expressions were taken from the literature. An assessment of the binary AgNO3–CsNO3 system based on the available experimental data is presented in this paper; the calculated phase diagram and thermodynamic functions agree well with experimental data. The parameters describing the Gibbs energies of all binary phases and the ternary liquid are used to predict the phase diagram of the AgNO3–CsNO3–NaNO3 system.

酸性 Fe（II） 水溶液の空気酸化による人工鉄さび粒子の構造および形態に対するアニオンの影響

In order to simulate the atmospheric corrosion of steel, artificial steel rust particles were synthesized by aerial oxidation of aqueous solutions containing FeCl2, FeSO4 and NaNO3, and the structure and morphology of the obtained particles were characterized by XRD and TEM. Needle-like SO42− containing Schwertmannite (Fe8O8(OH)6(SO4)) particles were mainly formed in FeCl2–FeSO4, FeSO4–NaNO3, FeCl2–FeSO4–NaNO3 systems, and the crystallization and particle growth of this material were not influenced by added Cl− and NO3−. The rod-shaped β-FeOOH particles were formed from in only FeCl3-NaNO3 system, though no marked change in crystallite and particle sizes of the β-FeOOH was recognized by adding NO3−. Accordingly, it can be suggested that the corrosive SOX gas and air-borne chloride strongly affect the rust formation in atmospheric corrosion of the steels.

Influences of inorganic salts on the pervaporation properties of zeolite NaA membranes on macroporous supports

Zeolite NaA membranes were hydrothermally synthesized on the macroporous supports using varying-temperature hot dip-coating seeding methods, and then were applied to pervaporative dehydration of the alcohol/water/salt mixtures at various temperatures to investigate the influences of salts on the pervaporation performance. Five kinds of salts NaCl, NaNO3, KCl, MgCl2, and CaCl2 were chosen to examine the effects of salt concentration, cations, and anions on the membrane performance. For the model system of ethanol/H2O/NaCl mixture, the water flux decreased largely with increasing salt concentrations which resulted from the reduced water driving force/activity and negative salt physical blocking on the outer membrane surface. For different cations, potassium ion led to the largest flux drop of 58.10%, while sodium ion, calcium ion, and magnesium ion for 25.88%, 22.31%, and 24.91%, respectively. This could be mainly attributed to a joint electrostatic interaction/ion exchange action.Flushing regeneration of the NaA membranes showed that complex flux behaviors were observed for the different salts. The water flux recovered up to 91.23% and 82.47% for the NaCl and NaNO3 system, respectively, indicating that the physical salt blocking effect on the flux drop can be removed therefore is reversible. The water flux recovered to 50.00% and 116.92% for salts of KCl and CaCl2, respectively. The irreversible flux drop probably resulted from the ion exchange and ion blocking effects. This work demonstrates that inorganic salts in the alcohol/H2O mixture decreased the flux or separation selectivity and should be avoided in industrial applications.

Erratum to: “Interactions in L-Phenylalanine/L-Leucine/L-Glutamic Acid/L-Proline + 2 M Aqueous NaCl/2 M NaNO3 Systems at Different Temperatures”

Density (ρ) and speed of sound (u) in 2 M aqueous NaCl and 2 M NaNO3 solutions of amino acids: L-phenylalanine, L-leucine, L-glutamic acid, and L-proline have been measured for several molal concentrations of amino acids at different temperatures. The ρ and u data have been used to calculate the values of isothermal compressibility and internal pressure at different temperatures. The trends of variations of κT and Pi with an increase in molal concentration of amino acid and temperature have been discussed in terms of solute-solvent and solute-solute interactions in the systems.

Interactions in L-phenylalanine/L-leucine/L-glutamic Acid/L-proline + 2 M aqueous NaCl/2 M NaNO3 systems at different temperatures

Interactions in L-phenylalanine/L-leucine/L-glutamic Acid/L-proline + 2 M aqueous NaCl/2 M NaNO3 systems at different temperatures

Hygroscopic behavior of wet dispersed and dry deposited NaNO3 particles

Previous controversial studies on the hygroscopic behavior of NaNO3 aerosol particles and our frequent observation of crystalline NaNO3-containing ambient particles prompted this hygroscopic study on NaNO3 particles. In this work, the hygroscopic behavior of individual NaNO3 particles of 2.5–4.0 μm in diameter is investigated on a single-particle basis using an optical microscopic technique. Quite different hygroscopic behavior between particles wet dispersed by the nebulization of aqueous NaNO3 solutions and dry deposited powdery particles was observed; i.e., most of wet dispersed particles continuously grew and shrank during humidifying and dehydration processes, respectively, and yet all the dry deposited particles had reproducible deliquescence and efflorescence relative humidities (DRHs and ERHs). The different behavior of the two NaNO3 systems is due to the different nucleation mechanisms. Our hygroscopic study of wet deposited NaNO3 particles indicates that they nucleate via homogeneous nucleation, but the time scale for the nucleation to occur is too long to be atmospherically relevant. And thus no efflorescence of the particles has been observed in the laboratory measurements. However, when chemical species acting as heterogeneous nuclei are present, then efflorescence occurs which can explain the observation of ambient crystalline NaNO3 particles. It is imperative to work with heterogeneous nucleation systems which are more relevant to the real world.

ChemInform Abstract: Unexpected Tandem Reaction of New Type Morita—Baylis—Hillman Adducts Promoted by [Hmim]HSO4/NaNO3 System.

AbstractA tandem reaction of Baylis—Hillman adducts (I) proceeds in the ionic liquid [Hmim]HSO4 / NaNO3 system and the unexpected products (III) and (IV) are formed via rearrangement and substitution.

Viscosities of l-Phenylalanine, l-Leucine, l-Glutamic Acid, or l-Proline + 2.0 mol·dm−3 Aqueous NaCl or 2.0 mol·dm−3 Aqueous NaNO3 Solutions at T = (298.15 to 328.15) K

Viscosity coefficients of l-phenylalanine, l-leucine, l-glutamic acid, or l-proline in 2.0 mol·dm−3 aqueous NaCl or 2.0 mol·dm−3 aqueous NaNO3 systems have been determined as a function of molal concentrations of amino acids at temperatures of (298.15, 303.15, 308.15, 313.15, 318.15, 323.15, and 328.15) K. Viscosity coefficients vary linearly with an increase in molal concentration of the amino acids. The trends of variation of viscosity values with an increase in molal concentration of l-phenylalanine, l-leucine, l-glutamic acid, and l-proline in 2.0 mol·dm−3 aqueous NaCl and 2.0 mol·dm−3 aqueous NaNO3 solutions and with an increase in temperature have been ascribed to the solute−solvent interactions operative in the solutions. The computed Jones−Dole B-coefficients have been also interpreted in terms of solute−solvent interactions.

Plutonium oxidation state distribution in natural clay and goethite

Distribution of Pu(IV) and Pu(V) oxidation states at trace initial concentrations (10 -10 -10 -11 mol L -1 ) was studied in a liquid- and solid-phase of natural clay and goethite systems. Experiments showed an increase in the concentration of Pu(III) up to 11% at pH 5 in solids of the natural clay -0.1 mol L -1 NaNO3 system containing Pu(IV) after 7-day contact. A kinetic sorption/reduction experiment with goethite suspensions (0.01 mol L -1 NaNO3 containing Pu(V)) indicated the presence of Pu(III) in the solids up to 15%.

Mass Diffusion Coefficients and Thermal Diffusivity in Concentrated Hydrothermal NaNO3 Solutions

Binary mass diffusion coefficients and thermal diffusivities for hydrothermal sodium nitrate solutions as a function of pressure (270 < P < 1000 bar), temperature (400 < T < 500 °C), and concentration (0.25 < C < 3.0 m) were measured by the laser-induced grating technique. In concentrated hydrothermal NaNO3 systems, the critical slowing down was significant as far as 300 bar from the phase-separation pressure, resulting in binary diffusion coefficients near the critical point that are comparable to values at ambient conditions. Further from the critical point the mass diffusion coefficients plateaued at their ordinary values. Ordinary binary mass diffusion was about 15 times faster than at 25 °C and atmospheric pressure. The ordinary binary mass diffusion coefficients were compared with predictions from hydrodynamic diffusion theory. Experimental results agreed well with predictions from the Stokes−Einstein equation, where the diffusing species was best represented by a hydrated contact ion pair. The Wilk...