7646-93-7Relevant articles and documents
High pressure behaviour of KHSO4 studied by electrical impedance spectroscopy
Bagdassarov,Lentz
, p. 16 - 21 (2005)
Measurements of the electrical conductivity were performed in KHSO 4 at pressures between 0.5 and 2.5 GPa and in the temperature range 120-350 °C by the use of the impedance spectroscopy. The temperatures of the α-β phase transition (TTr) and of the melting (T m), determined from the Arrhenius plots ln(σT) vs. 1/T, increase with pressure up to 1.5 GPa having dT/dP～+45 K/GPa. Above the pressure 1.5 GPa, the pressure dependencies of TTr and Tm are negative dT/dP～-45 K/GPa. At pressures above 0.5 GPa, the reversible decomposition of KHSO4 into K3H(SO4) 2+H2SO4 (and probably into K5H 3(SO4)4+H2SO4) affects the electrical conductivity of KHSO4, with the typical values of the protonic electrical conductivity, c. 10-1 S/cm at 2.5 GPa.
A study of molecular motion and Raman processes in K3H(SO 4)2 and KHSO4 single crystals by observation of 1H and 39K spin-lattice relaxation
Lim, Ae Ran,Jung, Won Ki,Han, Tae Jong
, p. 481 - 485 (2004)
The spin-lattice relaxation rates for 1H and 39K nuclei in K3H(SO4)2 and KHSO4 single crystals, which are potential candidate materials for use in fuel cells, were determined as a function of temperature. The spin-lattice relaxation recovery of 1H can be represented for both crystals with a single exponential function, but cannot be represented by the Bloembergen-Purcell-Pound (BPP) function, so is not related to HSO4 motion. The recovery traces of 39K, which predominantly undergoes quadrupole relaxation, can be represented by a linear combination of two exponential functions. The temperature dependences of the relaxation rates for 39K can be described with a simple power law T1-1=αT 2. The spin-lattice relaxation rates for the 39K nucleus in K3H(SO4)2 and KHSO4 crystals are in accordance with a Raman process dominated by a phonon mechanism.
Comparative thermoanalytical investigation of the cross-linking behaviour of three different paraffin waxes in the presence of potassium persulphate
Luyt,Ishripersadh,Timm
, p. 55 - 67 (1999)
The cross-linking of three different paraffin waxes - a hard oxidised wax, a medium wax, and a hard wax with narrow molar mass distribution - in the presence of potassium persulphate (PPS) was investigated thermoanalytically. DSC and TG curves for untreated waxes and waxes treated with different amounts of PPS were obtained and the observations were compared with gel content data obtained through gravimetric analysis. Although initial indications were that cross-linking did occur, reheat curves of wax/PPS mixtures as well as gel content data showed that no cross-linking occurred. It was, however, found that PPS most probably decomposed into KHSO4 and that this decomposition gave rise to functionalisation of the waxes.
Mechanochemical Decomposition of Dipotassium Peroxodisulfate by Dry Grinding
Motooka, Itaru,Nariai, Hiroyuki,Tsuhako, Mitsutomo
, p. 2163 - 2164 (1983)
The mechanochemical decomposition of dipotassium peroxodisulfate by dry grinding was investigated by X-ray diffractometry, infrared spectrophotometry, electron spin resonance (ESR) spectrometry, and thermal and volumetric analyses.When dipotassium peroxodisulfate (K2S2O8) was ground, type I of K2S2O8 was transformed into type II and then into type III.With prolonged grinding, the O-O linkage in K2S2O8 was severed to produce KSO4 radicals, which reacted with a little moisture to give KHSO4.
Superionic phase transition in KHSO4: A temperature-dependent raman investigation
Swain, Diptikanta,Bhadram, Venkata Srinu,Pradhan, Gopal K.,Bhat, S. Venkataprasad,Narayana, Chandrabhas,Rao
, p. 10040 - 10044 (2010)
Temperature-dependent Raman spectroscopic studies have been carried out on KHSO4 single crystals in the temperature range 298-493 K. A structural phase transition driven by the lattice and molecular disorder is observed at 473 K. The spectral data enable an understanding of the nature of the lattice disorder across the phase transition leading to the superionic phase. The disorder in the HSO4- polymeric hydrogen-bonded chain leading to a higher symmetry in the high temperature phase is clearly captured from our Raman results. The internal S-OH and S-O stretching modes and, to a limited extent, the external modes throw light on the disorder mechanism and the enhancement of conductivity after transition.
Synthesis, crystal structure, and vibrational spectra of M 4V2O3(SO4)4 (M = K, Rb, Cs)
Krasil'Nikov,Tyutyunnik,Zubkov,Berger,Perelyaeva, L. Ya.,Baklanova
, p. 491 - 500 (2011/08/08)
Synthesis was performed and physicochemical properties were studied for the M4V2O3(SO4)4 complexes, where M = K, Rb, or Cs. Their crystal structures were determined using the set of data from X-ray diffraction and neutron diffraction studies. All compounds crystallize in a triclinic lattice (space group P1, Z = 2) with the parameters: a = 7.7688(2), 7.8487(1), 8.1234(1) ?; b = 10.4918(3), 10.8750(2), 11.1065(1) ?; c = 11.9783(4), 12.1336(2), and 11.8039(1) ?; α = 76.600(2)°, 77.910(1)°, 79.589(1)°; β = 75.133(2)°, 75.718(1)°, 87.939(1)°; γ = 71.285(2)°, 72.189(1)°, 75.567(1)°; V = 881.78(5), 945.42(3), 1014.34(2) ?3 for K, Rb, Cs, respectively. The structure of M4V2O 3(SO4)4 was found to be formed by discrete complex anions V2O3(SO4) 4 4- incorporating two oxygen-bridged vanadium atoms in a distorted octahedral oxygen environment. The sulfate groups are coordinated by the vanadium atoms in the chelating mode with a large scatter of S-O interatomic distances and OSO angles. Every VO6 octahedron has a short terminal vanadium-oxygen bond with a length of about 1.6?. The V2O 3(SO4) 4 4- complex anions in potassium and rubidium compounds differ from that in Cs4V 2O3(SO4)4 in the type of symmetry and mutual spatial orientation. The vibrational spectra were presented and interpreted in line with the structural analysis data.
Phase ratios in the K2O-V2O4-SO 3 system at high sulfur trioxide concentrations
Krasil'nikov
, p. 258 - 262 (2008/10/09)
Phase ratios in the three-component oxide system K2O-V 2O4-SO3 in the region of the sulfur trioxide concentrations corresponding to its concentrations in the active component of vanadium catalysts for SO2/
Reaction of graphite with sulfuric acid in the presence of KMnO4
Sorokina,Khaskov,Avdeev,Nikol'skaya
, p. 162 - 168 (2007/10/03)
The reaction of graphite with sulfuric acid in the presence of KMnO 4 (oxidant : graphite ratio 0.027-0.55) involves consecutive and concurrent reactions: graphite intercalation and direct oxidation of the carbon matrix. The properties of graph
Method for preparing metal cyanide catalyst complexes using partially miscible complexing agents
-
, (2008/06/13)
Double metal cyanide catalysts (DMC) are complexed with complexing agents that are miscible in poly(propylene oxide) at higher temperatures and immiscible at lower temperatures. The complexing agent is a poly(ethylene oxide) polymer or a copolymer having a poly(ethylene oxide) block. The catalyst is easily removed from a polyether polyol.
Potassium Hydrogensulfate Dihydrogensulfate, K(HSO4)(H2SO4) - Synthesis and Crystal Structure
Kemnitz, E.,Werner, C.,Worzala, H.,Trojanov, S.
, (2008/10/08)
Single crystals with the composition KH3(SO4)2 have been synthesized from the system Potassium sulfate/sulfuric acid. The hitherto crystallographically not investigated compound crystallizes in the monoclinic space group P21/C (14) with the unit cell parameters a=7.654(3), b=11.473(5) and c=8.643(3) A, β=112.43(3)°, V=701.6 A^3, Z=4 and Dx=2.22 g.cm^-3. The structure contains two types of tetrahedra, SO3(OH) and (SO2(OH)2). These tetrahedra form tetramers via hydrogen bonds consisting ofboth, two SO3(OH) and SO2(OH)2 tetrahedra. The tetramers are linked to each other via hydrogen bonds. Potassium is coordinated by 9 oxygen atom s which belong to both kinds of tetrahedra. These potassium oxygen polyhedra are connected by common faces forming chains running parallel z.
