KOH H2O Research Articles

Structural characterization of new poly(ethylene oxide)‐based alkaline solid polymer electrolytes

A new class of alkaline solid polymer electrolytes (SPEs) based on poly(ethylene oxide) (PEO), potassium hydroxide (KOH), and water was investigated. The structure of the SPEs was studied by differential scanning calorimetry, thermogravimetric analysis (TGA), X-ray diffraction, and optical microscopy techniques. The existence of a crystalline complex between PEO, KOH, and H2O was evidenced for some compositions, depending on the O/K ratio. A possible structure was proposed, and a schematic phase diagram was established for this PEO–KOH–H2O system. The first conductivity measurements also revealed the great interest of these systems, with conductivity values up to 10-3 S/cm. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:601–607, 1997

Speciation of Al, Si, and K in supercritical solutions: Experimental study and interpretation

Corundum and quartz solubilities in KOH-H 2O and NaOH-H 2O solutions were measured at 500–700°C and 2 kbar. The observed solubility increase is interpreted by the formation of neutral alkalialuminum and alkali-silica complexes, with a minor contribution of SiO(OH) 3 − ions; A1(OH) 4 − ions are believed to be practically non-existent at these conditions. The equilibrium constants for these species have been determined, which allows the calculation of their concentration in solutions in the system K 2O-Al 2O 3-SiO 2-H 2O for any 3-mineral buffering association. These calculated concentrations were compared to direct composition measurements for solutions experimentally equilibrated with the considered 3-mineral assemblages. The agreement between calculated and measured concentrations is good for alkaline assemblages where the alkali-aluminum complex seems to be the main Al-bearing species with molalities ranging from 0.002 to 0.02. But for common assemblages such as quartz-mica-feldspar, the (K, Na)Al complex molality is negligible (10 −6 to 10 −4), whereas the experimental Al-concentrations (10 −3 m) suggest the presence of another Al-bearing species involving both silica and alkalies.

Hydrothermal growth of OH-phlogopite single crystals: I. Undoped growth medium

Single-crystal overgrowth of the OH-phlogopite mica on natural seeds has been produced using the convective solute transport method of hydrothermal growth. Best conditions were found to be: 6.5m KOH-H 2O as solvent, 540–550°C as growth temperature and 1 kbar as total pressure. From internally measured temperature differentials, the isothermal growth kinetics of individual mica faces could be determined as a function of nominal supersaturations σ N. Lateral {11 l}, {02 l}, {20 l} and {13 l} forms, in spite of their great surface structure anisotropy, develop nearly according to the spiral growth mechanism with no significant contribution of volume diffusion of the solute. Basal {001} faces develop erratically and even stop growing at greater σ N, being self-poisoned by mica nuclei; the growth habit simplifies and the platelet flattening becomes more pronounced as σ N increases.

The K3[Fe(CN)6]—KOHH2O photoetchant for InP

Crystal Research and TechnologyVolume 23, Issue 5 p. K81-K83 Short Note The K3[Fe(CN)6]—KOHH2O photoetchant for InP R. Srnánek, R. Srnánek Microelectronics Department, Slovak Technical University Mlynska dolina, Bratislava 812 19 CzechoslovakiaSearch for more papers by this authorA. Šatka, A. Šatka Microelectronics Department, Slovak Technical University Mlynska dolina, Bratislava 812 19 CzechoslovakiaSearch for more papers by this authorK. Seidel, K. Seidel Sektion Chemie, Karl-Marx-Universität Talstaße 35 Lripzig 7010, DDRSearch for more papers by this author R. Srnánek, R. Srnánek Microelectronics Department, Slovak Technical University Mlynska dolina, Bratislava 812 19 CzechoslovakiaSearch for more papers by this authorA. Šatka, A. Šatka Microelectronics Department, Slovak Technical University Mlynska dolina, Bratislava 812 19 CzechoslovakiaSearch for more papers by this authorK. Seidel, K. Seidel Sektion Chemie, Karl-Marx-Universität Talstaße 35 Lripzig 7010, DDRSearch for more papers by this author First published: May 1988 https://doi.org/10.1002/crat.2170230526AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume23, Issue5May 1988Pages K81-K83 RelatedInformation

Determination of defects in SiO 2 grown on Si(100)

The density of defects in SiO 2 films 1100 Å thick was determined by means of etching in a KOH-H 2O system. The effects of KOH concentration, etching duration and solution temperature on the defect density were studied. This method for determination of the defect concentration in SiO 2 films appears to be more sensitive and more rapid than use of the ethylenediamine-catechol-H 2O system.

Intramolecular hydride shift in some noncyclic isopropyl ketols

The acyclic ketols [Formula: see text] have been synthesized by a Reformatsky sequence. Each ketol undergoes intramolecular hydride transfer when refluxed in KOH–H2O–t-BuOH solution. When the procedure was applied to the synthesis of 34, hydride transfer occurred during the Reformatsky reaction to yield 33 instead. With longer reaction times, 33 underwent self-acylation and β-dicarbonyl cleavage to 37. Treatment of 33 with aqueous base gave a mixture of ketols 35 and 36 from hydride transfer and β-keto decarboethoxylation. The attempted conversion of the isobutyrate group of the Reformatsky intermediates 21 and 24 to tert-butyl was not practicable.

Homogeneous catalysis of deuterium transfer by potassium hydroxide and potassium methoxide D2–H2O and D2–CH3OH exchange

The kinetics and mechanism of exchange of deuterium between D2 and water and between D2 and methanol, catalyzed respectively by concentrated potassium hydroxide and potassium methoxide, has been studied between 348 and 398 K. In the D2–KOH–H2O case, the transfer of deuterium was found to be controlled by the rate of activation of the D2 molecule by OH−. Rapid exchange of D+ with the aqueous solution followed. From the D2–KOCH3–CH3OH studies, it was concluded that deuterium exchange depended upon the rates of both D2 activation by methoxide and interaction of the solvent with the transition, or encounter, complex. The dependence of second-order rate constants on solvent activity for both systems was determined by normalization of the exchange reaction rates to unit reagent activity. Analysis of the kinetic isotope effects for each system suggested that their increase with base concentration or temperature was due to solvation effects.

ChemInform Abstract: A STUDY OF THE INOSINE‐SODIUM HYDROXIDE‐WATER AND INOSINE‐POTASSIUM HYDROXIDE‐WATER SYSTEMS

Solubility data have been obtained for the inosine–NaOH–H2O and inosine–KOH–H2O systems at 30 °C. Two different solid phases of the potassium salt of inosine (C10H11N4O5·K·H2O and C10H11.5N4O5·0.5 K·0.5 H2O) were found in the latter system, while only one solid phase of the sodium salt of inosine (C10H11N4O5·Na·2.5 H2O) was found in the former system. The hemi-potassium salt of inosine is incongruent and is decomposed by pure water, whereas the mono-alkaline-metal salts are stable. The solubilities of the two mono-alkaline-metal salts of inosine in water were determined at 0–50 °C and formulated as follows: Na-salt, logS & = 0.01359·t+0.3997 K-salt, logS & = 0.00733·t+1.6513 where S represents the gram weight of the anhydrous salt per 100 g of water. The X-ray powder diffraction data of the above three salts are given.

A Study of the Inosine–Sodium Hydroxide–Water and Inosine–Potassium Hydroxide–Water Systems

Abstract Solubility data have been obtained for the inosine–NaOH–H2O and inosine–KOH–H2O systems at 30 °C. Two different solid phases of the potassium salt of inosine (C10H11N4O5·K·H2O and C10H11.5N4O5·0.5 K·0.5 H2O) were found in the latter system, while only one solid phase of the sodium salt of inosine (C10H11N4O5·Na·2.5 H2O) was found in the former system. The hemi-potassium salt of inosine is incongruent and is decomposed by pure water, whereas the mono-alkaline-metal salts are stable. The solubilities of the two mono-alkaline-metal salts of inosine in water were determined at 0–50 °C and formulated as follows: Na-salt, logS & = 0.01359·t+0.3997 K-salt, logS & = 0.00733·t+1.6513 where S represents the gram weight of the anhydrous salt per 100 g of water. The X-ray powder diffraction data of the above three salts are given.

Solubility in the potassium stannate – potassium hydroxide – water system at 0 to 95.0 °C

Solubilities and phase relations have been determined in the K2Sn(OH)6–KOH–H2O system between 0 and 95.0 °C. The isotherms consist of only one major solubility branch, that of K2Sn(OH)6, while the solubility branch of KOH is indistinguishable, since the isothermal invariant point is extremely close to the solubility of potassium hydroxide. Solid phases have been determined by Schreinemakers' method and checked with the polarizing microscope.