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A comparative study of the electrochemical deposition of cobalt on tin-doped indium oxide (ITO) substrate was carried out using electrochemical techniques in nitrate and chloride electrolytes. The bath used for the study in a nitrate medium contains 0.01 M of cobalt nitrate hexahydrate (Co(NO3)2. 6H2O) with 0.1 M of potassium nitrate (KNO3). For the chloride medium study, the electrolyte consists of a mixture of 0.01 M CoCl2 with 0.1 M potassium chloride (KCl). The cyclic voltammetry (CV) and the chronoamperometry (CA) have been used to study the kinetics, nucleation, and growth mechanism. The (CV) and (CA) measurements revealed that the electrodeposition of cobalt (Co) at a negative potential around −0.95 V versus SCE (saturated calomel electrode) is a quasi-reversible reaction controlled by the diffusion process in the two electrolytes. The measured current transient curves were compared to those calculated from Scharifker-Hills and Heerman-Tarallo models. It was found that a progressive three-dimensional (3D) nucleation mechanism governed the nucleation and the growth of Co on the ITO substrate in chloride solution, while in nitrate solution, the nucleation mechanism followed the instantaneous 3D model. The characterization of samples by X-ray diffraction had shown that the cobalt electrodeposited on ITO substrate has a hexagonal crystal structure whatever the electrolyte composition.

The electrode capacitance is studied as a function of the potential at various KCl contents in the KNO3 melt and various ac signal frequencies. At a certain critical potential, the addition of KCl is shown to lead to the appearance of an additional minimum in the anode branch of the capacitance curve, and an explanation of this effect is proposed.

A process scheme has been developed for the selective separation of sodium (Na) and potassium (K) from the bittern using a combination of adsorption – elution / evaporation / crystallization units. Adsorption – elution stages have been adopted for K enrichment from bittern using clinoptilolite as absorbent material and sodium nitrate as the subsequent eluent for the glass column. Then evaporation and cooling crystallization are appended to separate the sodium nitrate and potassium nitrate from the potassium-enriched solution. Afterwards, the mother liquor was completely recycled, and ten cycle experiments were carried out to determine that the purity of potassium nitrate, which exceeded 99%. Lastly, the endothermic process of preparing eluent and the exothermic process of potassium nitrate crystallization, can be capitalized by implementing a heat exchanger between the two processes and reduce the overall energy consumption. Thus, a heat flow simulation was carried out using Aspen plus software, and a temperature convergence was computed.

Saltpetre (KNO3; potassium nitrate) is one of the major ingredients of gunpowder. Simplex saltpetre (total 126 samples) together with gunpowder (total 93 samples) commodities which are curr...

The green synthesis of gold nanoparticles has attracted tremendous interest owing to their unique physicochemical properties and widespread applications which are primarily size-dependent. The stability, less reaction time, and use of biological resources as novel nanofactories as an alternative to conventional synthesis strategies are the main objectives of green synthesis approaches. However, to attain size-controlled synthesis from the biogenic route is still a challenge. Hence, use of nontoxic stabilizers becomes increasingly essential. Herein, we describe an emerging, simple, nonconventional approach to synthesize stable and size-controlled biogenic nanogold using cell lysate supernatant containing nitrate reductase of Bacillus licheniformis in the presence of Tween 20 and dodecanethiol respectively. The face-centered central composite design used for the optimization of gold nanoparticles (AuNPs) biosynthesis. The maximum AuNPs biosynthesis obtained using the optimized media variables, glucose (2.1 g/L), peptone (14.05 g/L), yeast extract (4.14 g/L), and potassium nitrate (3.91 g/L) was 0.769 a.u. Highly stable monodispersed nanogold of 10.4 ± 0.6 nm and 12.5 ± 0.9 nm sizes arranged in ordered self-assembly was obtained. The stability profile and kinetics of bioreduction was evaluated with respect to time, and the involvement of the nitrate reductase enzyme in bioreduction was validated by inhibitor study. The physicochemical properties of biogenic nanoparticles were characterized using multiple spectroscopy and microscopy techniques. The obtained nanogold demonstrated excellent bactericidal property against both gram-negative and gram-positive bacteria in size-dependent manner and thus could find tremendous utility in clinical, biological, and environmental applications as a broad-spectrum antibacterial agent.

The calorimetric method was employed to measure the heat effects of the interaction of isonicotinic and picolinic acids with HNO3in aqueous solutions over different pH ranges at 298.15 K and ionic strengths of 0.5, 1.0, and 1.5 against potassium nitrate. The heat effects of stepwise dissociation of the acids were determined. The standard thermodynamic characteristics (ΔrH°, ΔrG°, ΔrS°, ΔCp°) of the acid-base reactions in aqueous solutions of isonicotinic and picolinic acids were calculated.

In this study, catalyst formation [Pb(H2O)6][ATZ]·H2O (ATZ = azo tetrazolium anion) was successfully synthesized originally; meanwhile, the single-crystal structure of the compound was cultivated and analyzed by diffraction single-crystal method. The influence of the compound in which [Pb(H2O)6][ATZ]·H2O was used as combustion catalyst on the decomposition temperature of potassium nitrate was studied by TG–DSC. The result proved that [Pb(H2O)6][ATZ]·H2O can effectively reduce the decomposition temperature. In other words, [Pb(H2O)6][ATZ]·H2O can reduce the decomposition temperature of potassium nitrate, so the addition of [Pb(H2O)6][ATZ]·H2O can make potassium nitrate better to be used in the fields of initiating explosive device and fire engineering.

By the analytical gravimetric technique, the equilibrium saturated solubilities of l-serine and l-isoleucine in aqueous solutions of sodium nitrate (NaNO3) and potassium nitrate (KNO3) were measure...

Cuprous oxide (Cu2O) is an attractive material for photoelectrochemical (PEC) hydrogen production or photovoltaic application, because of its appropriate band gap, low material cost and non-toxic. In this paper, Cu2O films were obtained by comproportionation in acid cupric sulfate solutions with varying concentrations of potassium nitrate. Photoelectrochemical and electrochemical experiments, such as zero-bias photocurrent responses, voltammograms, and Mott-Schottky measurements, show that the Cu2O films grown in low (≤0.75 mol dm–3) and high (≥1.00 mol dm–3) nitrate ion concentrations presented n-type and p-type conductivity, respectively. Open circuit potential and polarization behavior were monitored to investigate the mechanism of modulating conductivity type. Nitrate ions consume protons in the plating solution during comproportionation with different concentrations of nitrate ions creating different pH at the Cu2O/solution interface. This gradient leads to the transformation of Cu2O films conductivity changing from n-type to p-type with increasing the concentration of nitrate ions in the plating solution. This method could be used to fabricate homojunction electrode on metal substrate for PEC hydrogen production or photoelectric application.

Commercial soda-lime silicate float glasses are chemically strengthened at 450 °C for 4 and 24 h in molten potassium nitrate containing small but controlled amount of NaNO3. The ion-exchange efficiency is determined from the measurement of surface compressive stress, potassium penetration and flexural strength. Chemical strengthening remains efficient also for NaNO3 additions up to 0.5 wt% (equivalent to ~1350 ppm Na) and the glass performance being identical to those obtained in pure KNO3, with no significative difference between “tin” and “air” side. For larger Na contamination residual stress and strength are reduced by an amount of about 25%.

This paper describes the leaching behaviour and dissolution kinetics of chalcopyrite wıth potassium nitrate in sulphuric acid solutions. Reaction temperature, solid/liquid ratio, stirring speed, chalcopyrite particle size, concentration of sulphuric acid and concentration of potassium nitrate solutions were selected as process parameters. The experimental results were successfully correlated with linear regression using the Statistical package program and dissolution curves were evaluated by the shrinking core models for solid-fluid systems. Finally, it was found that increasing reaction temperature and decreasing solid/liquid ratio caused an increase in the dissolution rate of chalcopyrite. The dissolution extent slightly increased with the increase in the stirring speed rate between 300-900 rpm under the experimental conditions. The activation energy was found as 78.25 kJ mol-1. It was seen that the leaching of chalcopyrite was controlled by surface chemical reactions.

Re-examination of published conductivity spectra for 2Ca (NO3)2∙3KNO3 (CKN) in its molten and glassy states, in terms of the MIGRATION concept, has brought to light new links between elementary processes occurring within one picosecond and their successful outcomes, i.e. those which determine the DC conductivities. The starting point of this analysis is the transition at 378 K, which arises from a change from a decoupled to a coupled transport mechanism. Remarkably, while there is a change in the shape of the conductivity dispersion and a jump in its onset frequency, there is no change in the temperature dependence of DC conductivity. What emerges from the analysis is a surprising continuity in high-frequency behaviour, with the activation energy and volume for elementary displacements, Eed and Ved, remaining constant from 300 K in the glass up to 500 K in the melt. The ratio, Eed/Ved, turns out to be equal to our previously defined DC activation moduli for CKN, given by EDC(T)/VDC(T) and Tg/(dTg/dp) for charge transport in the melt and structural relaxation at Tg, respectively. It seems that, at very short times, molten CKN behaves just like an elastic solid. The importance of elastic forces for ionic transport in CKN is corroborated by the finding that the published value of the high-frequency shear modulus of glassy CKN, G¥, matches those of Eed/Ved and hence of both activation moduli. The detected continuity in the picosecond behaviour of CKN across the glass transition could provide a new link between fragile liquids and glassy materials in general.

Extensive utilization of silver nanoparticles (NPs) in agricultural products results in their interaction with other chemicals in the environment. To study the combined effects of silver NPs with nicotinic acid and potassium nitrate (KNO3), a gel-free/label-free proteomic technique was used. Root length/weight and hypocotyl length/weight of soybean were enhanced by silver NPs mixed with nicotinic acid and KNO3. Out of a total 6340 identified proteins, 351 proteins were significantly changed, out of which 247 and 104 proteins increased and decreased, respectively. Differentially changed proteins were predominantly associated with protein degradation and synthesis according to the functional categorization. Protein-degradation-related proteins mainly consisted of the proteasome degradation pathway. The cell death was significantly higher in the root tips of soybean under the combined treatment compared to flooding stress. Accumulation of calnexin/calreticulin and glycoproteins was significantly increased under flooding with silver NPs, nicotinic acid, and KNO3. Growth of soybean seedlings with silver NPs, nicotinic acid, and KNO3 was improved under flooding stress. These results suggest that the combined mixture of silver NPs, nicotinic acid, and KNO3 causes positive effects on soybean seedling by regulating the protein quality control for the mis-folded proteins in the endoplasmic reticulum. Therefore, it might improve the growth of soybean under flooding stress.

In this study, we have succeeded in synthesizing a new hybrid material C18H12KNO11.H2O, whose asymmetric unit is composed of a molecule of ninhydrin and potassium nitrate. This crystal was obtained using the slow evaporation method at room temperature. The grown crystal was subjected to different characterization techniques, whose lattice structure was determined by X-ray diffraction on single crystal. It showed that the compound is crystallized in a monoclinic system with a Cm space group. As for EDAX analysis, it confirmed the presence of the different elements present in the compound. Besides, the thermal study (TGA) proved the stability of the crystal up to 240°C. The transparency of the crystal has been studied by the UV spectrum. Finally, second-order non-linear optical measurements were carried out using the Kurtz-Perry technique. It proved that the second harmonic generation efficiency of the crystal was found to be 0.22 times more than that of KDP. This result seems to be advocate for its use as a doubling material of frequency.

Kaolinite modification by grinding with H3PO4 was conducted to introduce more H+ for potassium exchange, therefore to enhance largely the capacity of potassium fixation. The precursor of Mg-Al LDH by milling both Mg and Al hydroxides was used to incorporate nitrate anions. The modified kaolinite and the synthesized LDH precursor were simultaneously used to achieve synergistic effect to raise the removal efficiency of potassium nitrate. The neutralization action between H+ ions exchanged with potassium cations from the kaolinite and OH– ions exchanged with nitrate anions from the LDH allows the continuous exchanging to remove out potassium nitrate at high efficiency, achieving the desalination of the very difficult alkali metals salts. The process provides an effective way to desalinate the difficult alkali metal salts and recover potassium from some specific industrial wastewaters with the products serving as a slow-release fertilizer.

The applicability of four commercially available ion exchange membranes: (Ralex AM-PP, CM-PP; Neosepta AMX, CMX; Selemion AMV, CMV; Ionsep AM-A, AM-C) for potassium nitrate synthesis by electrodialysis-metathesis was investigated. Solute back-diffusion, solvent transport, and potassium nitrate synthesis performance (the product purity, concentration and energy consumption) were evaluated for each IEM. The ED-M synthesis efficiency indicators: potassium nitrate concentration, purity, and current efficiency decreased with membrane type in the following order: Seleminon > Neosepta > Ionsep > Ralex. A Selemion AMV-CMV membrane pair performed the best among the membranes tested. Heterogeneous membranes were found to constitute a more efficient barrier for water transport by osmosis than homogeneous ones. Water transport along with ions was found to be the main source of water transport to products, leading to an undesired dilution of product solutions. All of these: back-diffusion, osmosis and water electrotransport can, however, be diminished by the selection of favorable ED-M conditions. The high performance of ED-M synthesis can be provided by using membranes with high fixed ion concentration and low water content. High selectivity, high conductivity and low water electrotransport ability are the most important membrane properties in terms of providing concentrated product under low energy consumption through ED-M.

Present study described the saturated solubilities of dl -alanine and dl -serine in pure and aqueous binary potassium nitrate solutions, were estimated by an analytical ‘formol titration’ procedure at 298.15 K. Various physicochemical and thermodynamical parameters like free energy change, density, molar volume, solvent diameter, co-solvent diameter, probable dipole moment of aqueous electrolyte systems, etc., were calculated at 298.15 K. The nature and degree of solubilities of such amino acids in aqueous potassium nitrate solutions were analyzed in terms of salting-in effect which was further justified by relative solubility and salting-in constants. Finally, thermodynamics of solute-solvent interactions in terms of transfer Gibbs free energetics were calculated and described the relative stability of the amino acids in pure and binary mixture of solvents.

The purpose of this study is to determine the effect of feeding rate, supersaturation level, stirring speed and the additives such as potassium nitrate (KNO3) and a new chelating agent (NCA) on the chord length distribution (CLD) as well as the crystal form of ammonium dihydrogen phosphate (MAP). The MAP crystals’ growth is investigated by using the FBRM G400 and the PVM V19 probes respectively in an MSMPR (Mixed Suspension Mixed Product Removal) crystallizer. Herein, the FBRM ensures an on-line determination of the CLD, which is expressed as the cumulative undersize square-weight percentage distribution of MAP crystals. CLD is statistically proportional to crystal size distribution. The PVM ensures the real-time monitoring of crystal morphology. In addition, an optical microscope is used to characterize the shapes of the crystals obtained in the MSMPR crystallizer. The chemical structures of the crystals are characterized by Fourier transform infrared (FT-IR) analysis. The population density of the nuclei, the nucleation rate, and the growth rate of the MAP crystals are also calculated. Industrial problems encountered in the production of MAP crystals, such as filtration and small crystal size, are eliminated especially in the presence of KNO3 and 1% NCA, which is proved by FBRM, PVM and number density theory application.

The electrical conductivities of sodium iodide (NaI), potassium iodide (KI), potassium chloride (KCl), sodium bromide (NaBr), lithium nitrate (LiNO3), potassium nitrate (KNO3), silver nitrate (AgNO3), potassium perchlorate (KClO4), sodium tetraphenylborate (NaBPh4), tetraethylammonium iodide (Et4NI) and tetra-n-butylammonium iodide (Bu4NI) in mixtures of methanol with water have been measured at 298.15 K. The obtained results were analyzed using the Fuoss–Justice equation and the low concentration chemical Model (lcCM). The limiting ionic conductances λo have been determined using the Fuoss–Hirsch assumption. The dependencies of the limiting molar conductances Λo and Walden products Λoη versus mixed solvent composition have been discussed.

Biochar samples produced from rice straw by pyrolysis at different temperatures (400 °C and 800 °C) and under different atmospheres (N 2 and CO 2 ) were applied to lettuce growth in a ‘preparation-application’ system. The conversion of potassium in the prepared biochar and the effect of the temperature used for pyrolysis on the bioavailability of potassium in the biochar were investigated. Root samples from lettuce plants grown with and without application of biochar were assayed by X-ray photoelectron spectroscopy (XPS). The optimal conditions for preparation of biochar to achieve the maximum bioavailability of potassium (i.e. for returning biochar to soil) were thus determined. Complex-K, a stable speciation of potassium in rice straw, was transformed into potassium sulfate, potassium nitrate, potassium nitrite, and potassium chloride after oxygen-limited pyrolysis. The aforementioned ionic-state potassium species can be directly absorbed and used by plants. Decomposition of the stable speciation of potassium during the pyrolysis process was more effective at higher temperature, whereas the pyrolysis atmosphere (CO 2 and N 2 ) had little effect on the quality of the biochar. Based on the potassium speciation in the biochar, the preparation cost, and the plant growth and rigor after the application of returning biochar to soil, 400 °C and CO 2 atmosphere were the most appropriate conditions for preparation of biochar.

This research focuses on the MIL-100(Fe) organometallic framework (MOF) promoting the thermal decomposition of potassium nitrate. A conventional MOF, MIL-100(Fe), is a chemical compound with a three-dimensional architecture composed of iron clusters and coordinating organic ligands. In the present study, MIL-100(Fe) was manufactured and dopped into potassium nitrate for thermogravimetric analysis to delineate the thermal decomposition behaviors of potassium nitrate. According to the thermal decomposition results, it shows that MIL-100(Fe) could promote potassium nitrate to reach the highest mass loss rate effectively at lower temperature conditions. Moreover, The results also delineate that the activation energy of thermal decomposition of potassium nitrate could be reduced by adding MIL-100(Fe) in potassium nitrate. On the other hand, the solid composite propellant composed of epoxy and potassium nitrate was also prepared as an example of the burning velocity test. The results show that the burning velocity could be enhanced by adding MIL-100(Fe) and also suggest the potential combustion catalyst for composite solid propellant.

Liquid extraction and microdroplet probing of the composition of reverse microemulsions (NaAOT+Tergitol NP-4, NaAOT, and Tergitol NP-4 in n-decane) with aqueous salt solutions (KNO3, NaNO3, and KNO3+NaNO3) were used to determine the distribution of Na+ and K+ between the surface layer and the micelle core in the processes of evaporation crystallization of KNO3 and NaNO3 salts. It is shown that, at high content of NaAOT, K+ cations in micelle core are virtually completely replaced by Na+ and no crystallization of KNO3 in NaAOT micelles is observed. At low content of NaAOT in mixed micelles and small solubilization capacity (less than 1 vol %) partial exchange takes place and crystallization of KNO3 begins from a mixture of KNO3+NaNO3 salts. During crystallization, micelle cores become depleted in potassium nitrate, which causes reverse exchange of K+ cations, associated with AOT–, for Na+ contained in the micelle core. As a result, mainly KNO3 crystallizes in mixed micelles.

Methods for providing stabilization of ammonium nitrate and expanding the application field of this oxidizing agent in gas-generating compositions used for various purposes were sought for. The results of a study of the physicochemical properties of ammonium nitrate with a melamine–potassium nitrate double additive introduced by mechanical mixing and crystallization from an aqueous (nonaqueous) solution at the boiling point are presented. The phase diagrams of the ammonium nitrate–melamine and ammonium nitrate–melamine–potassium nitrate systems, based on the results of a differential-thermal analysis, demonstrated that a phase-stable ammonium nitrate can be formed by using the method of crystallization from an aqueous (nonaqueous) solution at the boiling point. The resulting samples were examined by IR spectroscopy and X-ray diffraction analysis, and a conclusion was made that a new thermodynamically stable phase can be formed in the system with individual additives, and the introduction of a double additive leads to a combined effect: a thermodynamically stable crystal structure is formed, with the simultaneous slowing down of the nucleation and growth of a new phase in the course of a phase transformation.

Electroconductivity of heterogeneous ion-exchange membranes MK-40, MK-41, Ralex CM(H)-PP, MA-41, Ralex AM (H)-PP in ammonium nitrate, potassium nitrate, ammonium chloride and sodium chloride solutions was measured. The contribution of the gel, inter-gel and mixed phases of a heterogeneous membrane into the specific conductance of the sample was determined. By the method of high-frequency impedance spectroscopy the electrochemical characteristics of membranes MK-40 and MA-41 were studied. It is shown that the radius of the semicircle of the impedance hodograph is inversely proportional to the diffusion coefficient of a counter ion and directly proportional to the fraction of the inter-gel phase of the membrane. To measure the conductivity of the samples the contact-difference method was applied.

Soda lime silicate float glass was ion exchanged in potassium nitrate baths systematically contaminated with calcium nitrate up to 0.01 mol%. The results show that surface compression and flexural strength are dramatically depressed if the treatment is carried out in salt containing calcium nitrate in excess of 0.0015 mol%, this being related to more limited sodium-potassium exchange on the surface. The presence of calcium in the salt accounts for a “blocking” effect of the conventional Na-K exchange which is shown to be thermodynamically less favoured than Na-Ca one, especially at higher temperature.

New materials for thermochemical storage of concentrated solar heat are highly desirable for making this emerging technology competitive with the traditional sensible and latent heat storage. Keeping this in mind, we have prepared calcium hydroxide modified with potassium nitrate and studied its de-/rehydration dynamics by differential scanning calorimetry and thermogravimetry techniques. The following notable observations are described for the modified Ca(OH)2: (1) an acceleration of the dehydration and reduction of its temperature as compared with the pure hydroxide; (2) the temperature reduction depends on the KNO3 content Y and reaches 35 °C at Y = 5 wt%; (3) the addition of KNO3 only slightly reduces the dehydration heat which remains promising for heat storage applications. Fast rehydration of the doped CaO is observed at T = 290–360 °C and P(H2O) = 23–128 mbar, and its rate strongly depends on both temperature and pressure. De- and rehydrated products were studied by the BET analysis and IR-spectroscopy to elucidate possible ways for the salt to influence the Ca(OH)2 dehydration. The mechanism involving a chemical interaction between the salt and the hydroxide is discussed. The new material exhibits a large heat storage density, fast de-/rehydration and adjustable decomposition temperature, and may be considered as a promising candidate for thermochemical storage of concentrated solar energy.

The present study proposes a comparative study of potassium nitrate and feldspar as a reaction promoting agents for the carbothermal reduction of barite at high temperature. Result reveals that after the incorporation of potassium nitrate and feldspar the reduction percentage with potassium nitrate was about 59% and in case of feldspar, it was about 30%. Thus use of potassium nitrate for the carbothermal reduction of barites has proved to be pretty effective to increase the amount of water soluble barium sulphide which is the key material to manufacture various barium chemicals. Hence the study is very important, as it possesses dual benefits in terms of maximum utilisation of barite and more contribution towards national economy.

The conformation of a hydrophobic, weak cationic poly(2-diisopropylamino)ethyl methacrylate (PDPA) brush was studied using neutron reflectometry as a function of aqueous solution pH, ionic strength, and anion identity. In pH 4, 10 mM potassium nitrate the brush is highly charged, resulting in an extended, dilute conformation; at pH 9 the uncharged brush collapses to a single, dense layer. The brush response to added salt at constant pH (4.5) for varying concentrations of the potassium salts of acetate, nitrate, and thiocyanate revealed ion-specific conformations of the brush. At low ionic strength (0.1 mM) the brush was collapsed, independent of salt identity, while at higher ionic strengths (up to 500 mM) the conformation was dependent on counterion identity. The brush exhibited extended conformations in the presence of kosmotropic acetate counterions, while collapsed conformations were retained in the presence of strongly chaotropic thiocyanate counterions. The brush showed a richer set of behaviors in the solutions containing the weakly chaotropic nitrate anion, being similar to acetate (swollen) at intermediate concentrations but similar to thiocyanate (collapsed) at high salt concentrations. Numerical self-consistent field (nSCF) simulations indicate that the response of the brush to pH changes is dominated by the hydrophobicity of the polymer at pH values near the pKa. Furthermore, the simulations reveal that the addition of a single Flory–Huggins interaction parameter analogous to the hydrophilicity of the counterion is sufficient to replicate the observed specific anion response of a hydrophobic weak polyelectrolyte brush.

Potassium-containing BEA zeolites were prepared by ion-exchange from NH4-BEA with potassium nitrate aqueous solution or ion-exchange combined with impregnation. The samples were used as basic catalysts for aldol condensation of furfural and acetone studied in a batch reactor at 100 °C, autogenous pressure and a reaction time of 2 h. To establish a relationship between physico-chemical properties and catalytic behavior of BEA zeolites, the samples were characterized by XRD, N2 adsorption, FTIR, calorimetry, and TGA. The ion-exchanged K-BEA catalysts exhibited low activity in the aldol condensation because of a weak strength of intrinsic basic sites. In contrast, the samples prepared by ion exchange combined with impregnation possessed strong basic sites, plausibly K2O clusters, and demonstrated appreciable activity in the aldol condensation. TGA results proved that, in contrast to acidic zeolites, basic sites of impregnated BEA samples hardly contribute to the formation of heavy carbonaceous deposits during the reaction what could be advantageous for the stable behavior of catalysts.

Solubility data in the diagonal sections of the quaternary reciprocal 2KCl + Ca(NO3)2 → 2KNO3 + CaCl2–H2O system at 25 and 15°C are presented. It has been shown that the quaternary system has no stable diagonal at the studied temperatures, but contains a stable pair of salts, namely, potassium nitrate and calcium chloride. The obtained data can be used to optimize the thermal and concentrational parameters of the synthesis of potassium nitrate from calcium nitrate and potassium chloride.

Structural features and dielectric behavior of polymeric systems based on tetrazole are investigated after combining them with potassium nitrate (KNO3) and potassium chloride (KCl). It was found that the salt additives added to the system exist in the form of the singular crystallites that is the closed inclusions chaotically distributed inside polymeric matrix. Injection of potassium nitrate increases the value of dielectric permittivity on the studied interval of frequencies. Potassium chloride reduces the value of dielectric permittivity of the polymeric system in the field of high frequencies, and increases it in the field of low frequencies. Addition of salt increases the specific conductivity of composites that indicates increase in degree of dissociation of ionogenic substances. In the studied systems, ionogenic substances, besides salt additives, including water and remains of catalysts.

A mild and efficient strategy for the nitration of amino-substituted pyrazoles/triazole employing a mixture of potassium nitrate and concentrated sulfuric acid (KNO3/H2SO4) as a nitrating reagent proceeded smoothly to give nitramino-substituted products. These were treated with corresponding bases to give energetic salts 1–10. The compounds were fully characterized, and single crystal X-ray diffraction studies were obtained for 1, 4, 6, and 10. The physical properties and detonation performance were measured or calculated. Salts 1, 2, 6, 8, and 9 exhibited excellent detonation performance and acceptable sensitivities as well as good stabilities, which suggested that they have potential to be useful as high-performance explosives.

Solubility of the amino acids in aqueous electrolytes plays a major role in influencing their solvation thermodynamics which is further associated with their biochemical and biophysical deeds in human physiology. In the present study the solubility of l -proline in aqueous sodium chloride (NaCl), sodium nitrate (NaNO 3 ), potassium chloride (KCl) and potassium nitrate (KNO 3 ) solutions were determined in five equidistant temperatures by using an analytical ‘gravimetric’ method. The experimental results were compared with that of the earlier in order to explain the factors playing the role during the course of solvation of l -proline in the experimental electrolytes solutions. Related thermodynamic and molecular properties such as standard transfers Gibbs energetics, molar volume, density, dipole moment and solvent diameter of the experimental solutions were also evaluated in this study. The above mentioned factors were applied to find out the chemical effects of the transfer Gibbs energies. Different factors such as nature of the solute, interactions between solute and solvents, etc., were characterized by using different physical and analytical loom.

It is found that the samples of silicon-phosphorus-antimony ion exchangers obtained in experimental batches are close in terms of their properties to the sample obtained under laboratory conditions, and they exhibit identical characteristics in regeneration of potassium nitrate melt. In order to optimize the process of ion exchange strengthening of glass it is proposed that two ion exchangers be introduced into the melt: K[Sb(OH)4] for sorption of Na+ ions and silicon-phosphorus-antimony for polyvalent impurity ions.

Nitrogen-doped porous carbons were prepared using a facile method, with low-biotechnology fulvic acid potassium salts as a precursor. The prepared carbons had a high surface area (1623 m2 g−1) and good electrochemical properties, making them suitable electrode materials for supercapacitors. Nitrogen-doped porous carbons were tested as an electrode in both 6 M KOH aqueous solution and different concentrations KNO3 aqueous solution. The nitrogen-doped porous carbons with unique microstructure and nitrogen functionalities exhibited a capacitance of 235 F g−1 in a 6 M KOH aqueous solution. Electrochemical investigation showed that the nitrogen-doped porous carbons exhibited a broad potential operational window in a 2.5 M KNO3 aqueous solution. Furthermore, a high capacitance retention of 88.1 % was achieved even after 5000 cycles at 1.7 V. Potassium nitrate solutions in a wide range of concentrations were also proven to be promising electrolytes for electrochemical capacitors because they are cheap, noncorrosive, electrochemically stable, and compatible to diverse current collectors.

The Cu2+–glycine–L-histidine system is studied calorimetrically at 298.15 K and an ionic strength of 0.2, 0.5, and 1.0 in aqueous solutions containing potassium nitrate. The standard thermodynamic parameters (ΔrH°, ΔrG°, ΔrS°) of complexation processes are determined.

The aim of this study is the preparation of magnetic nanoparticles and coating with glycine to remove heavy metals such as Cu +2 . The magnetic nanoparticles were prepared by co-precipitation method using using ferrous sulphate and potassium nitrate in presence of potassium hydroxide. Different instrumental analysis such as XRD, TEM, SEM and EDAX were used to study the magnetic nanoparticles which produced and comparing it after coated with glycine. The optimum conditions which reflect the high efficiency of removal are pH 10, concentration of the heavy metal 200 ppm, dosage 0.05 g and for 24 h duration time. Therefore we recommend using magnetic nanoparticles coated with glycine for removal of heavy metals.

The systematic investigation of RNO3 salts (R = Li, Na, K, and Cs) as electrolyte additives was carried out for lithium-battery systems. For the first time, the abundant and extremely available KNO3 was proved to be an excellent alternative of LiNO3 for suppression of the lithium dendrites. The reason was ascribed to the possible synergetic effect of K(+) and NO3(-) ions: The positively charged K(+) ion could surround the lithium dendrites by electrostatic attraction and then delay their further growth, while simultaneously the oxidative NO3(-) ion could be reduced and subsequently profitable to the reinforcement of the solid-electrolyte interphase (SEI). By adding KNO3 into the practical Li-S battery, the discharging capacity was enhanced to average 687 mAh g(-1) from the case without KNO3 (528 mAh g(-1)) during 100 cycles, which was comparable to the one with the well-known LiNO3 additive (637 mAh g(-1)) under the same conditions.

A metathesis electrodialysis (MED) system for the conversion of potassium nitrate from potassium chloride is developed. The experiments are carried out in recirculation mode using a four compartment electro-conversion unit of 200 cm2 effective membrane area with 10 cell pairs. The cation exchange membrane and anion exchange membrane used for the present study are converted from a styrene divinylbenzene based interpolymer film by sulfonation and chloromethylation followed by amination, respectively. Membranes are characterized by means of chemical, mechanical, and thermal properties. Membranes show excellent electrochemical properties with adequate thermal and mechanical stability. About 97% conversion of potassium nitrate is achieved during the sets of experiments with high product purity (99%). Four different applied potentials (1.5, 2, 2.5, and 3 V/cell pair) are used during different sets of experiments in metathesis electrodialysis, out of which 2 V/cell pair is found to be more efficient potential wi...

Fe–K/Al2O3 catalysts supported on cordierite monoliths were prepared using four washcoating suspensions containing different dispersible boehmites. The influence of the inherent properties of these alumina precursors on the textural properties, morphology and mechanical integrity of the catalytic layer were studied together with the activity of the monolithic catalyst in the simultaneous removal of soot and NOx. The textural and structural properties of the washcoat strongly determine the mobility of potassium species and therefore the activity of the different catalyst prepared. Calcination at 650 °C and complete removal of such mobile potassium nitrate species results in similar activity that no longer depends on the textural and morphological properties of the catalytic layer, determined by the type of alumina precursor used.

Molten salts possess significant potential for use as heat transfer fluids (HTFs) and/or thermal storage media in advanced high-temperature concentrating solar power (CSP) plants. However, the thermal performance of these materials is hindered by typically low thermal conductivity—on the order of 1 W/m-K in the solid phase and less in the liquid phase. Much work has been done to improve the thermal conductivity of HTFs through the addition of nanoparticles of higher conductivity, such as metallic nanoparticles or nanoparticulate graphite. These nanofluids display improved thermal conductivity and otherwise behave similarly to the pure HTFs. This investigation proposes such a system, focusing on the nitrate salts: potassium nitrate, sodium nitrate, and the potassium–sodium nitrate eutectic (54 weight percent potassium nitrate), with melting points of 334 °C, 306 °C, and 222 °C, respectively. Attention is also paid to use of these materials as latent heat thermal energy storage (TES) materials—i.e., phase change materials (PCMs). The nitrate salt melt is a highly oxidative environment, so the use of carbonaceous materials or elemental metals may be hampered by degradative effects. Hence, this investigation specifically examines cupric oxide (CuO) nanoparticle-enhanced nitrate salts systems. The thermophysical properties (e.g., thermal diffusivity, latent heat) of the salt-nanoparticle systems are measured. Further, temperature-variant FTIR spectroscopy is used to determine any potential degradation of the salt after thermal cycling. The suitability of the enhanced nitrate salts systems, in regard to the chemical stability of the additive and the improvement of the thermal performance of the system relative to the pure salts, is demonstrated.

The applicability of KNO3 synthesis by electrodialysis metathesis (ED-M) following: NaNO3 + K2SO4 → KNO3 + Na2SO4 reaction scheme using Ralex PP membranes was examined. The effects of operating parameters: current density, feed concentration and composition on a current efficiency, solute and solvent transport were investigated. Current efficiencies observed were close to 100% and purity of the products exceeded 99%. It was found that electroosmosis contributed to water transport the most. At the same time, osmosis and solute back diffusion did not influence the process.

Three oxidants, hypochlorous acid, chlorate and nitrate, were assessed for their ability to oxidise chalcopyrite (CuFeS2). Hypochlorous acid was the most aggressive oxidant trialled, with copper extraction reaching a plateau after 1–5 h. Extraction in this system was complete at room temperature when reagent concentrations of 0.3–0.4 M were supplied. Optimal conditions utilising chlorate as an oxidant measured final extractions of 66–72% after 168 h. Optimal conditions utilising nitrate enabled a final extraction of 92% in systems using milled ore. Gangue dissolution in the presence of each oxidant varied. The system utilising nitrate resulted in comparatively high levels of magnesium and aluminium extraction, 28% and 32%, respectively. The chlorate system, over an identical time period and similar solution pH, had magnesium and aluminium extractions of 7% and 6%. These data, together with those for silicon dissolution, are indicative of incongruent silicate dissolution. Iron extraction data indicated that ferric hydroxy-oxide precipitates formed during leaching in both nitrate and chlorate systems. All systems tested offered improved rates of copper extraction relative to systems utilising ferric sulfate as an oxidant.