Ion association in solutions of HCl in DMSO–water mixtures: ultrasonic absorption studies

1978 ◽  
Vol 56 (14) ◽  
pp. 1881-1888
Author(s):  
Peeter Kruus ◽  
M. Jacqueline Mcguire
Keyword(s):  
Equilibrium Constants ◽  
Ion Association ◽  
Rate Theory ◽  
Ultrasonic Absorption ◽  
Relaxation Equation ◽  
A Value ◽  
Diffusion Controlled ◽  
Absorption Studies ◽  
Excess Absorption ◽  
Absorption Measurements

Ultrasonic absorption measurements are reported for the System HCl–dimethylsulfoxide (DMSO)–water in the frequency range 3.5 to 140 MHz. For ail solutions studied, the excess absorption due to the presence of HCl can be fitted well with a single relaxation equation. For 0.10 mol ℓ−1 solutions of HCl in DMSO–water mixtures, no further relaxations at higher frequencies are likely. Reasonable results are obtained when the ultrasonic results are analyzed assuming the process responsible for the excess absorption to be the dissociation–association equilibrium of HCl, and using equilibrium constants determined from conductivity (C. Cooke etal. Electrochim. Acta, 20, 591 (1975)). The value of |ΔVeff| is 20–25 cm3 mol−1 and Kass is approximately 3 × 109ℓ mol−1 s−1, as compared to a value of 10 × 109ℓ mol−1 s−1 calculated from limiting conductivities assuming diffusion-controlled rate theory.

Proton Transfer Kinetics in Medium-strong Inorganic Acids

1973 ◽  
Vol 51 (14) ◽  
pp. 2297-2305 ◽  
Author(s):  
David Charles Hodgkin ◽  
Peeter Kruus
Keyword(s):  
Proton Transfer ◽  
Aqueous Solutions ◽  
Rate Constants ◽  
Reasonable Agreement ◽  
Ultrasonic Absorption ◽  
Absolute Rate ◽  
Absorption Data ◽  
Inorganic Acids ◽  
Diffusion Controlled ◽  
Excess Absorption

A method of obtaining relative and absolute rate constants for proton transfer equilibria is described. It is suitable for equilibria of the type[Formula: see text]in dilute (< 0.1 M) solutions of medium strong inorganic acids. To obtain absolute values of kd, kr it is necessary to know the value of ΔV0 for the equilibrium. Ultrasonic absorption data for aqueous solutions of H3PO4, H3AsO4, and H2SO4 at 20, 10, and 0 °C are presented together with data at 20 °C for H3PO3, H2SeO3, HIO4, NaHSO4, KHSO4, and NH4HSO4. From analysis of the concentration dependence of the excess absorption, values of Ka are calculated for these acids, and values of kd, kr for those where ΔV0 is available. The Ka obtained are in reasonable agreement with literature values except for HIO4 and H2SeO4. The absolute values of kr for H3PO4, H3AsO4, and HSO4− indicate that the diffusion controlled recombination process postulated is complete when the ions are about 15 Å from each other.

Ion Pair Formation in Solutions of Alkali Halides in Dimethyl Sulfoxide: Ultrasonic Absorption Studies

1971 ◽  
Vol 49 (19) ◽  
pp. 3107-3113 ◽  
Author(s):  
D. R. Dickson ◽  
P. Kruus
Keyword(s):  
Dimethyl Sulfoxide ◽  
Solvent Molecule ◽  
Alkali Halides ◽  
Ion Pair ◽  
Ultrasonic Absorption ◽  
Absorption Studies ◽  
System Water ◽  
Excess Absorption ◽  
Stepwise Formation ◽  
Rate Of Movement

The ultrasonic absorption of dimethyl sulfoxide solutions of several alkali halides has been studied in the frequency range 1.5 to 52 MHz. An excess absorption, relaxing between 3 and 8 MHz, was observed. The relaxation was assigned to the final step in the stepwise formation of a contact ion pair, with the relaxation frequency controlled by the rate of movement of a solvent molecule rather than an ion. Data on the system water – dimethyl sulfoxide are also presented and the effect of water on the relaxation discussed.

scholarly journals Evaluation of equilibrium constants for the interaction of lactate dehydrogenase isoenzymes with reduced nicotinamide-adenine dinucleotide by affinity chromatography

1975 ◽  
Vol 151 (3) ◽  
pp. 631-636 ◽  
Author(s):  
R I Brinkworth ◽  
C J Masters ◽  
D J Winzor
Keyword(s):  
Lactate Dehydrogenase ◽  
Affinity Chromatography ◽  
Equilibrium Constants ◽  
Mouse Tissue ◽  
Rabbit Muscle ◽  
Muscle Lactate ◽  
Sodium Phosphate Buffer ◽  
A Value ◽  
Series Of Experiments ◽  
Reduced Nicotinamide Adenine Dinucleotide

Rabbit muscle lactate dehydrogenase was subjected to frontal affinity chromatography on Sepharose-oxamate in the presence of various concentrations of NADH and sodium phosphate buffer (0.05 M, pH 6.8) containing 0.5 M-NaCl. Quantitative interpretation of the results yields an intrinsic association constant of 9.0 × 104M−1 for the interaction of enzyme with NADH at 5°C, a value that is confirmed by equilibrium-binding measurements. In a second series of experiments, zonal affinity chromatography of a mouse tissue extract under the same conditions was used to evaluate assoication constants of the order 2 × 105M−1, 3 × 105M−1, 4 × 105M−1, 7 × 105M−1 and 2 × 106M−1 for the interaction of NADH with the M4, M3H, M2H2, MH3 and H4 isoenzymes respectively of lactate dehydrogenase.

scholarly journals Ultrasonic absorption measurements in mammalian tissues

1978 ◽  
Vol 63 (S1) ◽  
pp. S13-S13
Author(s):  
S. A. Goss ◽  
L. A. Frizzell ◽  
F. Dunn
Keyword(s):  
Ultrasonic Absorption ◽  
Mammalian Tissues ◽  
Absorption Measurements

Modulated microwave absorption in single crystal Bi–Sr–Ca–Cu–O

1992 ◽  
Vol 7 (4) ◽  
pp. 837-843
Author(s):  
R.S. Rubins ◽  
Z. Trybula ◽  
S. Waplak ◽  
John E. Drumheller ◽  
Donglu Shi ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Modulation Amplitude ◽  
Broad Line ◽  
Low Field ◽  
A Value ◽  
Flux Trapping ◽  
Line Absorption ◽  
The Relationship ◽  
Maximum Field ◽  
Absorption Measurements

Modulated microwave absorption measurements at 9.3 GHz were made on the low field absorption observed in the superconducting phase of Bi–Sr–Ca–Cu–O. The line intensity observed with a low modulation amplitude of 50 mOe showed a maximum between 70 K and 80 K and dropped to zero near 95 K. With a modulation amplitude of 10 Oe, an additional broad line absorption was observed above 88 K, peaking in intensity near 95 K, and disappearing above 100 K. Hysteresis, associated with flux trapping, occurred when the maximum field Hmax in a sweep cycle exceeded a critical value H*(T), which varied from about 7 Oe at 59 K to 1 Oe at 82 K. For Hmax > H*, the hysteresis splitting at first varied linearly with (Hmax – H*), later saturating at a value δHmax(T). Above 70 K, the relationship δHmax = b(T0 – T) was obeyed with T0 = 92.3 K and b· = −0.3 Oe/K for H perpendicular and b· = −0.23 Oe/K for H parallel to the c-axis.

Cu2SnS3 Inorganic-Organic Hybrid Structures for Photovoltaic Applications

2015 ◽  
Vol 1784 ◽  
Author(s):  
Sandra Dias ◽  
S. B. Krupanidhi
Keyword(s):  
Electron Microscopy ◽  
Hybrid Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hybrid Device ◽  
Organic Hybrid ◽  
A Value ◽  
Transmission Electron ◽  
Absorption Studies ◽  
Photovoltaic Applications

ABSTRACTWe report the synthesis of Cu2SnS3 (CTS) nanostructures and its incorporation into an inorganic-organic hybrid device to enhance the photoresponse under AM 1.5 G solar illumination. The nanostructures were structurally and optically characterized. From X-ray diffraction (XRD) and Transmission electron microscopy (TEM) the CTS nanocrystals were found to be tetragonal. Flower like structures of CTS were obtained as seen from Scanning electron microscopy (SEM). A band gap of 1.4 eV was obtained from absorption studies. Two devices have been studied, P3HT: PCBM = 1: 1 and CTS: P3HT: PCBM = 8:1:1. The photocurrent increased from a value of 2.33 mA at dark to 2.5 mA for the P3HT-PCBM blend to 3.36 mA for CTS: P3HT: PCBM = 8:1:1 device. The responsivity, sensitivity, external quantum efficiency and specific detectivity increased from 18.81 mA/W, 1.07, 4.25% and 6.88 × 108 Jones respectively for P3HT:PCBM sample to 189.97 mA/W, 1.44, 42.9% and 6.95 × 109 Jones for CTS: P3HT: PCBM = 8:1:1 sample at 1V bias and 1 Sun illumination intensity. The time dependent photoresponse was stable over different ON-OFF cycles. From the fit to the rise and decay curves, the rise and decay time constants were obtained.

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