Solid Potassium Chloride Research Articles

Comparative Long-Wave Infrared Laser-Induced Breakdown Spectroscopy Employing 1-D and 2-D Focal Plane Array Detectors.

Long-wave infrared (LWIR) emissions of laser-induced plasma on solid potassium chloride and acetaminophen tablet surfaces were studied using both a one-dimensional (1-D) linear array detection system and, for the first time, a two-dimensional (2-D) focal plane array (FPA) detection system. Both atomic and molecular infrared emitters in the vicinity of the plasma were identified by analyzing the detected spectral signatures in the infrared region. Time- and space-resolved long-wave infrared emissions were also studied to assess the temporal and spatial behaviors of atomic and molecular emitters in the plasma. These pioneer temporal and spatial investigations of infrared emissions from laser-induced plasma would be valuable to the modeling of plasma evolutions and the advances of the novel LWIR laser-induced breakdown spectroscopy (LIBS). When integrated both temporally (≥200 µs) and spatially using a 2-D FPA detector, the observed intensities and signal-to-noise-ratio (SNR) of single-shot LWIR LIBS signature emissions from intact molecules were considerably enhanced (e.g., with enhancement factors up to 16 and 3.76, respectively, for a 6.62 µm band of acetaminophen molecules) and, in general, comparable to those from the atomic emitters. Pairing LWIR LIBS with conventional ultraviolet-visible-near infrared (UV/Vis/NIR) LIBS, a simultaneous UV/Vis/NIR + LWIR LIBS detection system promises unprecedented capability of in situ, real-time, and stand-off investigation of both atomic and molecular target compositions to detect and characterize a range of chemistries.

Effective mass path integral simulations of quasiparticles in condensed phases

The quantum many-body problem in condensed phases is often simplified using a quasiparticle description, such as effective mass theory for electron motion in a periodic solid. These approaches are often the basis for understanding many fundamental condensed phase processes, including the molecular mechanisms underlying solar energy harvesting and photocatalysis. Despite the importance of these effective particles, there is still a need for computational methods that can explore their behavior on chemically relevant length and time scales. This is especially true when the interactions between the particles and their environment are important. We introduce an approach for studying quasiparticles in condensed phases by combining effective mass theory with the path integral treatment of quantum particles. This framework incorporates the generally anisotropic electronic band structure of materials into path integral simulation schemes to enable modeling of quasiparticles in quantum confinement, for example. We demonstrate the utility of effective mass path integral simulations by modeling an exciton in solid potassium chloride and electron trapping by a sulfur vacancy in monolayer molybdenum disulfide.

Joint Analysis of the Heat Capacity and Thermal Expansion of Solid Potassium Chloride

This paper describes a joint correlation analysis of the heat capacity Cp(T) and volume thermal expansivity β(T) of potassium chloride (KCl) over the entire temperature range of its solid state (from absolute zero to Tm). A trilinear model for the β(Cp) correlation dependence, consistent with experimental data and consisting of three smoothly joined linear segments, has been constructed. The differential Gruneisen parameter γ ' ~ ∂β/∂Cp, convenient for describing such behavior, has three characteristic steps. Analysis of data in this model has made it possible to tabulate thermodynamic and thermal expansion data for solid KCl, in good agreement with the most reliable experimental data.

Indirect Methods of Determination of K:Al Mole Ratio in Molten Chloroaluminates

Chloroalumninate melts are prospective media for the second loop of molten salt nuclear reactors and low-temperature electrowinning and electrorefining processes for metals that can not be obtained from aqueous solutions. Application of chloroaluminates in such technologies is limited by the problem of corrosion resistance of construction materials. The alloys and steels corrosion resistance strongly depends on KCl-AlCl3 melt composition (K : Al mole ratio). When the mole ratio of potassium-to-aluminum is high (basic melts) precipitation of insoluble potassium chloride can cause the abrasion of the material. From the other side increasing AlCl3 content in the melt leads to increase of the red-ox potential due to formation of Al2Cl7 - species (acidic melts). Thus the importance of knowledge and ability to control K : Al mole ratios is undoubted for the industrial application of chloroaluminate melts.Chemical analysis based methods allow to determine the general content of potassium and aluminium in the melt. However chloroaluminate melts are very sensitive to moisture that can cause AlCl3 hydrolysis and result in decreasing «actual» aluminum chloride concentration in the melt. At increasing K : Al mole ratio (for example, due to evaporation of AlCl3) precipitation of solid potassium chloride can take place and this may lead to erroneous results of hemical analysis. Therefore indirect methods for determining K : Al mole ratio in molten chloroaluminates are needed to obtain correct data and perform possible required adjustment of the acid-base properties of KCl-AlCl3 electrolytes.In the present work potentiometry (with aluminum working electrode), cyclic voltammetry (with tungsten working electrode) and X-Ray diffraction analysis were suggested for indirect control of K : Al mole ratio. The electrochemical measurements were conducted using an Autolab PGSTAT 302N potentiostat/galvanostat. The electrode potentials were measured vs. aluminum reference electrode (ARE) consisting of aluminum wire lowered into KCl-AlCl3 melt containing solid KCl and separated from the working electrolyte by a diaphragm. X-ray diffraction patterns were recorded on an X’PERT PRO MPD X-Ray spectrometer with high speed 3D detector PIXCEL and an inert chamber Anton Paar HTK 1200N.Calibration curves of aluminum working electrode vs. ARE in studied chloroaluminates were obtained in temperature range from 300 to 500 oC. They strongly depend on acid-base properties of KCl-AlCl3 electrolytes and thus can be used for K/Al molar ratio determination. Reproducibility of the obtained values with temperature and salt composition was demonstrated.Cyclic voltammetry can be effectively used for determining acid-base properties of molten КСl-AlCl3 systems. In case of basic melts the cyclic voltamogramm consists of two edge peaks at 2.2-2.3 V and -0.3-0 V that correspond to dissolution of tungsten and deposition of aluminum. The presence of acidic Al2Cl7 - species leads to the appearance of additional maxima on the voltammograms. The influence of AlCl3 concentration on the position of these peaks and their intensity was investigated.The use of modern X-ray diffraction methods allows to perform high-precision qualitative and quantitative analysis. However the determination of low concentrations of «free» potassium and aluminum chlorides in quenched chloroaluminate electrolytes is complicated due to overlapping of weak lines of KCl and AlCl3 phases (present in small amounts) with the lines of major KAlCl4 monoclinic phase. High inclination of salt crystals to preferential orientation during sample preparation constitutes another difficulty for determining K : Al mole ratio by X-ray diffraction. In the present work we suggest using full profile Rietvelds analysis that allows to separate the contribution of diffraction patterns of different crystal phases even in the case of their overlapping. The results of X-ray diffraction determination of the composition of potassium chloroaluminate melts agree well with the electrochemical data.

Study of small chlorine‐doped potassium clusters by thermal ionization mass spectrometry

The theoretical calculations have predicted that nonmetal-doped potassium clusters can be used in the synthesis of a new class of charge-transfer salts which can be considered as potential building blocks for the assembly of novel nanostructured material. In this work, K(n)Cl (n = 2-6) and K(n)Cl(n-1) (n = 3 and 4) clusters were produced by vaporization of a solid potassium chloride salt in a thermal ionization mass spectrometry. The ionization energies (IEs) were measured, and found to be 3.64 ± 0.20 eV for K(2)Cl, 3.67 ± 0.20 eV for K(3)Cl, 3.62 ± 0.20 eV for K(4)Cl, 3.57 ± 0.20 eV for K(5)Cl, 3.69 ± 0.20 eV for K(6)Cl, 3.71 ± 0.20 eV for K(3)Cl(2) and 3.72 ± 0.20 eV for K(4)Cl(3). The K(n)Cl(+) (n = 3-6) clusters were detected for the first time in a cluster beam generated by the thermal ionization source of modified design. Also, this work is the first to report experimentally obtained values of IEs for K(n)Cl(+) (n = 3-6) and K(n)Cl(n-1) (+) (n = 3 and 4) clusters. The ionization energies for K(n)Cl(+) and K(n)Cl(n-1) (+) clusters are much lower than the 4.34 eV of the potassium atom; hence, these clusters should be classified as 'superalkali' species.

Encapsulation and Permeability Characteristics of Plasma Polymerized Hollow Particles

In this protocol, core-shell nanostructures are synthesized by plasma enhanced chemical vapor deposition. We produce an amorphous barrier by plasma polymerization of isopropanol on various solid substrates, including silica and potassium chloride. This versatile technique is used to treat nanoparticles and nanopowders with sizes ranging from 37 nm to 1 micron, by depositing films whose thickness can be anywhere from 1 nm to upwards of 100 nm. Dissolution of the core allows us to study the rate of permeation through the film. In these experiments, we determine the diffusion coefficient of KCl through the barrier film by coating KCL nanocrystals and subsequently monitoring the ionic conductivity of the coated particles suspended in water. The primary interest in this process is the encapsulation and delayed release of solutes. The thickness of the shell is one of the independent variables by which we control the rate of release. It has a strong effect on the rate of release, which increases from a six-hour release (shell thickness is 20 nm) to a long-term release over 30 days (shell thickness is 95 nm). The release profile shows a characteristic behavior: a fast release (35% of the final materials) during the first five minutes after the beginning of the dissolution, and a slower release till all of the core materials come out.

ChemInform Abstract: New Ideas on Phase-Transfer Catalysts: SN2 Reaction with a Solid Ionophoric Salt.

A new mechanism of substitution between n-hexyl bromide (RBr) and solid potassium chloride in toluene under phasetransfer catalysis conditions is suggested, involving the formation of intermediates, adsorbed on the solid phase, viz., two binary (KCl·QX and KX·QBr) and two ternary (QX·KCl·RBr and QBr·KX·RCl) complexes. According to this mechanism, the catalytic activity of onium salts (QX) in the substitution changes in the order QI > QBr > QCl. The nature of the catalyst cation has little or no effect on the reaction rate. A general rule is proposed according to which in this reaction the substrate is attacked by a stronger nucleophile whereas a weaker nucleophile accepts the leaving group of the substrate. These and earlier data are interpreted in term of the SN2 process occurring on the solid-phase surface. The structure of the ternary complexes and the role of the phase-transfer catalyst are discussed.

Oral Solid Potassium Chloride and Anticholinergic Medications: A New Drug Interaction for an Old Drug?

Oral Solid Potassium Chloride and Anticholinergic Medications: A New Drug Interaction for an Old Drug?

Application of optical reflectometry for characterization of polyelectrolyte–protein multilayers

It is known that the build-up of polyelectrolyte multilayers can be followed in situ by means of stagnation point optical reflectometry. Application of optical reflectometry to characterization of multilayers obtained by exposing a suitable substrate to solutions of a cationic homopolymer and an oppositely charged protein was investigated. In all experiments, bovine serum albumin (BSA) was used as the negatively charged component. The weak polyelectrolyte poly(dimethylaminoethyl)methacrylate (PAMA) or the strong polyelectrolyte poly(2-vinyl- n-methylpyridinium iodide) (PVP +) was used as the cationic homopolymer. Silica in the form of silicon wafers carrying an oxide layer was used as the solid substrate and potassium chloride or phosphate buffer were used as the supporting electrolyte. The influence of ionic strength, pH, type of cationic homopolymer (strong or weak), and protein concentration were investigated. It was shown that stagnation point optical reflectometry can be a useful method for characterization of the formation of multilayers containing polyelectrolyte and protein layers.

All-solid-state reference electrodes based on conducting polymers

A novel construction of solution free (pseudo)reference electrodes, compatible with all-solid-state potentiometric indicator electrodes, has been proposed. These electrodes use conducting polymers (CP): polypyrrole (PPy) or poly(3,4-ethylenedioxythiophene) (PEDOT). Two different arrangements have been tested: solely based on CP and those where the CP phase is covered with a poly(vinyl chloride) based outer membrane of tailored composition. The former arrangement was designed to suppress or compensate cation- and anion-exchange, using mobile perchlorate ions and poly(4-styrenesulfonate) or dodecylbenzenesulfonate anions as immobilized dopants. The following systems were used: (i) polypyrrole layers doped simultaneously by two kinds of anions, both mobile and immobilized in the polymer layer; (ii) bilayers of polypyrrole with anion exchanging inner layer and cation-exchanging outer layer; (iii) polypyrrole doped by surfactant dodecylbenzenesulfonate ions, which inhibit ion exchange on the polymer/solution interface. For the above systems, recorded potentials have been found to be practically independent of electrolyte concentration. The best results, profound stability of potentials, have been obtained for poly(3,4-ethylenedioxythiophene) or polypyrrole doped by poly(4-styrenesulfonate) anions covered by a poly(vinyl chloride) based membrane, containing both anion- and cation-exchangers as well as solid potassium chloride and silver chloride with metallic silver. Differently to the cases (i)-(iii) these electrodes are much less sensitive to the influence of redox and pH interferences. This arrangement has been also characterized using electrochemical impedance spectroscopy and chronopotentiometry.

Lyoluminescence of inorganic salts

Lyoluminescence of various alkali halides, carbonates, phosphates and ammonium persulfate was measured. The light emission depends on the nature of cation and anion and, for oxysalts, on the acid character of the material. The lyoluminescent effect tends to vanish in the presence of crystallization water. A free radical mechanism must be probably considered in some cases. The incorporation of bivalent earth alkali and transition metal cations in solid potassium chloride leads to an enhancement of lyoluminescence.

The vapour composition and pressure over solid potassium chloride: new mass-spectrometric results and effusion masses

The composition of the vapour phase over solid potassium chloride was analyzed mass spectrometrically in the temperature range 930 K to 1040 K. A linear least-squares fit of dimer mole fraction x against temperature T is given by: x = {7.45·10−4·(T/K)−0.5458} ±0.02. We combined our mass-spectrometric result with the vapour compositions from three different literature sources to obtain a best fit for x in the temperature range 600 K to 1050 K. The result is x = 8.51·10−7·(T/K)2−8.70·10−4·(T/K)+ 0.23. The apparent vapour pressure was determined by means of effusion masses in the temperature range 840 K to 1040 K. The vapour compositions were combined with our effusion masses and the vapour pressures from seven literature sources to obtain a best value for the third-law molar enthalpies of sublimation of the monomer and of the dimer. The results are ΔgsHom(298.15 K, KCl) = (221.7 ± 0.7) kJ·mol−1, and ΔgsHom(298.15 K, K2Cl2) = (260.2 ± 1.0) kJ·mol−1. With these results we calculated the standard molar enthalpies of formation of the two gaseous species and the reaction enthalpy between monomer and dimer: ΔfHom(298.15 K, KCl, g) = −215.0 kJ·mol−1; ΔfHom(298.15 K, K2Cl2, g) = −613.2 kJ·mol−1; ΔrHom(298.15 K, 2KCl = K2Cl2) = 183.2 kJ·mol−1. A review of the literature on this subject is given from 1936 until now.

New ideas on phase transfer catalysts: SN2 reaction with a solid ionophoric salt

AbstractA new mechanism of substitution between n‐hexyl bromide (RBr) and solid potassium chloride in toluene under phasetransfer catalysis conditions is suggested, involving the formation of intermediates, adsorbed on the solid phase, viz., two binary (KCl·QX and KX·QBr) and two ternary (QX·KCl·RBr and QBr·KX·RCl) complexes. According to this mechanism, the catalytic activity of onium salts (QX) in the substitution changes in the order QI > QBr > QCl. The nature of the catalyst cation has little or no effect on the reaction rate. A general rule is proposed according to which in this reaction the substrate is attacked by a stronger nucleophile whereas a weaker nucleophile accepts the leaving group of the substrate. These and earlier data are interpreted in term of the SN2 process occurring on the solid‐phase surface. The structure of the ternary complexes and the role of the phase‐transfer catalyst are discussed.

Formation of adsorption complexes in phase‐transfer nucleophilic substitution. Kinetic analysis of solid‐phase system

AbstractThe kinetics of the nucleophilic substitution between n‐hexyl bromide and solid potassium chloride (KCl) in toluene were studied in the presence of catalytic amounts of tetra‐n‐butylammonium bromide at 84°C. This reaction is characterized by an induction period that disappears on activation of the solid salt. The substitution with the activated salt constitutes a reversible pseudo‐first‐order reaction with variable orders in the substrate and the catalyst equal to 0 ≤ n ≤ 1. A quantitative increase in the solid KCl at first accelerates the substitution reaction, but when the level reaches KCl/RBr ≥ 7 the rate constant is no longer influenced by the amount of salt. Comparing data obtained with kinetic equations for several possible substitution schemes, the mechanism of the reaction can be derived, including the formation of a ternary adsorption complex (TC) from the substrate, catalyst and solid salt. The data obtained allow the evaluation of the equilibrium constant of TC formation (KΣ= 20.48 l2 mol−2) and the rate constant of its disintegration into substitution products (k+ = 0.75 × 10−2 s−1). Through kinetic analysis the adsorption sequence on the surface of the solid salt was determined, including primary formation of the binary complex KCl.QX and subsequent TC formation. The concentration of active KCl molecules, estimated on the basis of the primary kinetic data is 10−2 M and is commensurate with the catalyst concentration. This concentration of active KCl molecules is achieved owing to the formation of subcolloidal‐sized particles in the process of the solid salt activation.

The oxidation state of fission fragment iodine in potassium chloride

Iodine isotopes in fission fragments formed by recoil from a film of uranium oxide into solid potassium chloride during reactor irradiation, have been shown to exchange with both oxidised iodate and reduced iodide carriers. On annealing after the irradiation the oxidised form of the fission fragment decreases initially, and then increases relative to the reduced form depending on the temperature of the annealing. The effect is interpreted quantitatively as a reaction with electron donors, such as chloride ion defect centres formed in the lattice, which also undergo a simultaneous annealing process to form electron acceptors, such as chlorine. Estimates are made of the activation energies involved.

Monte-Carlo computations for some simple models accounting for ionic polarization in potassium chloride

Some simple but crude models accounting for ionic polarization in alkali halides have been examined by means of Monte-Carlo constant-pressure computations; for comparisons to be made in a way as unambiguous as possible, the models have been applied to simulate solid and molten potassium chloride, with the same two-body potential and at the same temperatures and pressure as in a previous paper. One of those models was found to lead to a considerably improved agreement with experimental data. The polarization contribution was found to be around 1% of the total energy.

Monte-Carlo computations for molten potassium chloride based on the Pauling potential

Monte-Carlo computations in the NpT-ensemble are reported for solid and liquid potassium chloride at atmospheric pressure and temperatures between the melting and boiling points. The calculations are based on the Pauling potential with parameters proposed by Fumi and Tosi from an analysis of solid-state data. The calculated volumes are found to be much larger than the experimental values. The discrepancy ranges from 14% of the experimental volume in the case of the solid at the melting point to 31% for the liquid at the normal boiling point. The discrepancies in the enthalpy are considerably smaller but these results are considered to be of less significance than those obtained for the volume. Comparison with the Monte-Carlo work of Woodcock and Singer shows the Pauling potential to be much less satisfactory than the Born-Huggins-Mayer form.

Determination of the Concentrations of Cation and Anion Vacancies in Solid Potassium Chloride

The mobility of cation vacancies and the equilibrium concentration of cation and anion vacancies in solid potassium chloride are calculated from measurements of the electrical conductivity of pure potassium chloride and solid solutions of strontium chloride in potassium chloride.

Transference Numbers of Solid Potassium Chloride with Strontium Chloride, Potassium Oxide, and Sodium Sulfide as Additives

The transference number of cations in solid potassium chloride at 600°C has been found to be 0.88 in accordance with previous experiments of Tubandt, Reinhold, and Liebold. Addition of strontium chloride causes increase of the transference number approaching unity. Addition of potassium oxide and sodium sulfide, respectively, lowers somewhat the transference number of cations and accordingly increases the transference number of anions. These results are in accordance with the Schottky disorder model, but the presence of interstitial cations apart from cation and anion vacancies cannot be ruled out.

Preparation of Potassium Nitrate from Solid Potassium Chloride and Nitrogen Peroxide1

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation of Potassium Nitrate from Solid Potassium Chloride and Nitrogen Peroxide1Colin W. Whittaker, Frank O. Lundstrom, and Albert R. MerzCite this: Ind. Eng. Chem. 1931, 23, 12, 1410–1413Publication Date (Print):December 1, 1931Publication History Published online1 May 2002Published inissue 1 December 1931https://doi.org/10.1021/ie50264a024RIGHTS & PERMISSIONSArticle Views98Altmetric-Citations13LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (507 KB) Get e-Alerts