Ultrasonic Absorption Method Research Articles

Sound velocity and density of liquid Ni68S32 under pressure using ultrasonic and X-ray absorption with tomography methods

A new experimental setup for simultaneous P-wave velocity (VP) and density (ρ) measurements for liquid alloys is developed using ultrasonic and X-ray absorption methods combined with X-ray tomography at high pressures and high temperatures. The new setup allows us to directly determine adiabatic bulk moduli (KS) and to discuss the correlation between the VP and ρ of the liquid sample. We measured VP and ρ of liquid Ni68S32 up to 5.6GPa and 1045K using this technique. The effect of pressure on the VP and ρ values of liquid Ni68S32 is similar to that of liquid Fe57S43. (Both compositions correspond to near-eutectic ones.) The obtained KS values are well fitted to the finite strain equation with a KS0 value (KS at ambient pressure) of 31.1GPa and a dKS/dP value of 8.44. The measured VP was found to increase linearly with increasing ρ, as approximated by the relationship: VP [m/s]=1.29ρ [kg/m3] – 5726, suggesting that liquid Ni–S follows an empirical linear relationship, Birch's law. The dVP/dρ slope is similar between Ni68S32 and Fe57S43 liquids, while the VP–ρ plot of liquid Ni–S is markedly different from that of liquid Fe–S, which indicates that the effect of Ni on Birch's law is important for understanding the VP–ρ relation of planetary and Moon's molten cores.

ChemInform Abstract: Micellar Effect on the Kinetics of the Base Equilibrium of Amino Acids Studied by the Ultrasonic Absorption Method

Ultrasonic relaxation absorption has been measured in aqueous solutions of amino acids (tryptophan, leucine, glycine, phenylalanine, asparagine) in the absence and in the presence of micelles of sodium dodecylsulphate. The relaxation absorption was ascribed to the base equilibrium of amino acids, and the rate constants, the base dissociation constant, and the volume change of the reaction were obtained. The smaller micellar catalytic effect for the base equilibrium of amino acids, compared to those of amines and ammonia was ascribed to the electrostatic effect of the carboxylate group. The reaction mechanism, including the interactions of amino acid and the SDS micelles, were discussed.

Proton-Transfer Reaction in Aqueous Propylamine Solution with Poly(vinyl alcohols) by Ultrasonic Absorption Method

Abstract Ultrasonic absorption coefficients were measured in aqueous solutions of propylamine at 25 °C in both the absence and presence of 2.01 g dm-3 (poly(vinyl alcohols) (PVA’s)) with the number average degree of polymerization of 500, 900, 1500, and 2000. No excess absorption was observed in solutions without propylamine. A single relaxational absorption was observed in the concentration range from 0.0241 to 0.201 mol dm-3 of propylamine in both the presence and absence of PVA’s. The relaxational absorption was attributed to a perturbation of the equilibrium associated with a proton-transfer reaction from the concentration dependence of the relaxation frequency and the maximum absorption per wavelength. The rate and equilibrium constants and the standard volume change of the reaction were determined in individual solutions with PVA’s. As a result, it was found that the diffusion-controlled reaction rate constant remains constant, or increases slightly, even though the solution viscosity increases. The effect of the polymers on the reaction was interpreted in terms of an interaction between the PVA’s and the reaction intermediate and a solvent structural change.

Interrelation between proton transfer reactions and solvent structure studied by the ultrasonic absorption method

Ultrasonic absorption coefficients in aqueous solutions of methanol at 1.00, 2.00, 3.00, 4.00, and 6.00 mol dm−3 and in those of ethanol at 1.00, 2.00, 3.00, 4.00, 5.00, and 6.00 mol dm−3 have been measured in the frequency range from 0.8–220 MHz at 25.0 °C. No excess absorption has been observed in any of these solutions except in the 5.00 and 6.00 mol dm−3 ethanol solutions, for which a Debye-type single relaxational equation has been fitted. In order to see the effects of methanol and ethanol on the dynamic characteristics of aqueous amine solutions, the ultrasonic absorption measurements have been carried out in aqueous solutions of propylamine containing 1.00, 2.00, 3.00, 4.00, and 6.00 mol dm−3 methanol and 1.00, 2.00, 3.00, and 4.00 mol dm−3 ethanol. The excess absorption has been observed, and the frequency dependence of the ultrasonic absorption coefficients has been well described by the Debye-type single relaxational equation. The cause of the relaxation is due to a perturbation of equilibrium associated with a proton transfer reaction. The rate constants have been determined from hydroxide ion concentration dependence of the relaxation frequency, and the standard volume change of the reaction has been calculated from the reactant concentration dependence of maximum absorption per wavelength. It has been found that the addition of methanol causes the decrease in the diffusion controlled rate constant and the trend of the decrease is more remarkable in the concentration range from 3.00–6.00 mol dm−3. On the other hand, the rate constant in the solution with ethanol has decreased linearly with an increase in the ethanol concentration. The reverse rate constant and the volume change of the reaction have not been affected by the addition of the two alcohols. Using a theoretical equation for the diffusion controlled reaction, a diffusion coefficient of the hydroxide ion has been determined at various concentrations of the additives. These results are discussed in relation to the effects of methanol and ethanol on water structure.

Kinetic study of the protolysis of benzoic acid derivatives in a micelle of dodecylammonium chloride

T. Isoda, M. Yamasaki, H. Yano and S. Harada, J. Chem. Soc., Faraday Trans., 1997, 93, 449 DOI: 10.1039/A605621K

Effect of 2-Propanol on Proton Transfer Reaction by Ultrasonic Absorption Method

Ultrasonic absorption coefficients in aqueous solutions of 2-propanol in the concentration range from 1.00 to 3.99 mol dm-3 have been measured over the frequency range from 3.0 to 220 MHz. In the s...

Micellar Catalytic Effects on the Kinetics of the Ionization of Basic Amino Acid and Acidic Amino Acid Studied by the Ultrasonic Absorption Method

Base equilibria of arginine (basic amino acid) in the absence of a micelle and then in a micellar solution of sodium dodecyl sulfate (SDS) have been studied by ultrasonic absorption measurements. Forward (γ 2 k f ) and backward (k b ) rate constants, the apparent base dissociation constant K b (=k b /γ 2 k f ), and the volume change (ΔV) for the reaction were obtained. Micellar effects for arginine were greater than those for a neutral amino acid measured previously. This is discussed in terms of total charge of the amino acids. Similar experiments were carried out for aspartic acid (acidic amino acid)-cationic micelle of dodecyl-ammonium chloride (DAC). Relaxation was considered due to the protolysis of aspartic acid. A slightly lower micellar effect than that for an aromatic carboxylic acid-dodecylammonium chloride (DAC) system was noted. ΔV was smaller than that for an aromatic carboxylic acid with the same pK a

Specific micellar catalytic effects of the protolysis of ortho-Benzoic acid derivatives studied by the ultrasonic absorption method

Ultrasonic relaxation absorption has been observed in aqueous solutions of ortho-benzoic acid derivatives (OBAD) in the presence of a micelle of tetradecyltrimethylammonium bromide (TTAB). Relaxation absorptions were ascribed to the protolysis of acids on the surface of the micelle. The apparent dissociation constant (pKa=kb/γ2kf), rate constants (γ2kf, kb) and volume change (ΔV) for the reactions were determined. The dependence of rate constants on pKa for OBAD was compared with that for meta- and para-benzoic acid derivatives (BAD). It was especially noticeable that the dissociation of OBAD in the micellar solution is depressed more than that in aqueous solution. This can be explained as due to electrostatic effects, the polarity of solution and solvation in the TTAB micellar solution. The dependence of ΔV of OBAD on pKa was also compared with that of BAD. The result was considered to be due to differences in solute–solvent interactions and the situation around OBAD and BAD in the micellar solution.

Solvent Effect on Proton Transfer Reaction Rate by Ultrasonic Absorption Method

Abstract Some equipment for a resonance method was constructed in order to obtain ultrasonic absorption coefficients in a frequency range less than 10 MHz. Using this apparatus, the measurable frequency range was extended down to 2.5 MHz. No relaxational absorption was observed in an aqueous solution of 2-propanol at 2.70 mol dm−3 in the frequency range from 2.5 to 220 MHz. A relaxational absorption was observed in aqueous solutions of n-propylamine in the presence of 2.70 mol dm−3 2-propanol. The frequency dependence of the absorption coefficient was analyzed by a usual Debye-type relaxational equation. Excellent agreement between calculated and experimental values was obtained in the frequency range measured. The relaxational absorption was attributed to the perturbation of equilibria associated with a proton transfer reaction: The rate constants and the standard volume change for the first step of the reaction were determined from the concentration dependence of the relaxation frequency and the maximum absorption per wavelength. It was found that the forward rate constant decreased and the standard volume change increased when the values were compared with those in the absence of 2-propanol. The results were discussed in relation to water structure and hindrance for the proton transfer reaction by the additives.

Cationic micellar effect on the kinetics of the protolysis of aromatic carboxylic acids studied by the ultrasonic absorption method

The protolysis of carboxylic acids has been kinetically studied by the ultrasonic absorption method in the presence of tetradecyltrimethylammonium bromide (TTAB) micelles in aqueous solution. The carboxylic acids studied were classified into two categories, one capable of formation of intramolecular hydrogen bond, namely the salicylic acid derivatives (SAD) and the other which cannot form the bond, namely the benzoic acid derivatives (BAD). The rate constant (γ2kf, kb), the apparent dissociation constant (Ka), and the volume change of the reaction (ΔV) were obtained. Different Ka dependences of the rate constants observed for SAD and BAD are discussed in relation to the effect of intramolecular hydrogen bond. pKa dependences were also observed for ΔV of SAD and BAD. These dependences are larger than those in aqueous solution. This result was attributed to the change of arrangement of water molecules around the solute in micellar solution and aqueous solution.

Effect of Ether Oxygen on Proton Transfer and Aggregation Reactions of Amines in Water by Ultrasonic Absorption Method

Abstract Ultrasonic absorption coefficients in the frequency range from 6.5 to 220 MHz have been measured in aqueous solutions of 3-ethoxy- and 3-butoxypropylamine as functions of their concentrations along with the sound velocity at 2.5 MHz and the density. In a 3-ethoxypropylamine solution, only one relaxational absorption has been observed up to 3.0 mol dm−3. The cause has been clarified to be due to a proton-transfer reaction of the amine from the concentration dependences of the relaxation frequency and the relaxational amplitude. The rate and thermodynamic parameters have been determined and reasonable values have been obtained as a diffusion-controlled reaction. In the solution of 3-butoxypropylamine, another relaxation process in addition to that due to the proton-transfer reaction has been observed in the concentrations of more than 0.5 mol dm−3. This relaxation process has been attributed to a perturbation associated with an aggregation reaction, 4A↔A4, from the concentration dependences of the relaxation frequency and the relaxational amplitude of the absorption. The rate and thermodynamic constants for the proton-transfer and aggregation reactions have been determined. It has been found from a comparison of the results for the two solutions and others reported previously that the introduction of ether oxygen into amine molecules has little influence on the proton-transfer reaction, but prevents the formation of aggregates due to the hydrophobic interaction. It has also been seen from the results of 3-butoxypropylamine solutions that the butoxyl group has a fairly high ability of hydrophobic interaction and that nonionized molecules form aggregates in the aqueous solution.

Micellar effect on the kinetics of the base equilibrium of amino acids studied by the ultrasonic absorption method

Ultrasonic relaxation absorption has been measured in aqueous solutions of amino acids (tryptophan, leucine, glycine, phenylalanine, asparagine) in the absence and in the presence of micelles of sodium dodecylsulphate. The relaxation absorption was ascribed to the base equilibrium of amino acids, and the rate constants, the base dissociation constant, and the volume change of the reaction were obtained. The smaller micellar catalytic effect for the base equilibrium of amino acids, compared to those of amines and ammonia was ascribed to the electrostatic effect of the carboxylate group. The reaction mechanism, including the interactions of amino acid and the SDS micelles, were discussed.

Ultrasonic Absorption Studies of the Micellar Catalyzed Reaction of the Base Dissociation of Ammonia

Abstract The base dissociation of ammonia has been studied by an ultrasonic absorption method in both the absence and presence of SDS micelle in aqueous solution, and kinetic parameters were obtained. The micellar catalyzed reaction mechanism, including the interactions of ammonium ion with SDS micelles, are discussed.

Micellar Catalytic Effect on the Base Dissociation of Methylamine Studied by the Ultrasonic Absorption Method

Abstract Micellar catalytic effects on the base dissociation of methylamine have been studied by ultrasonic absorption method. The dissociation constant, the rate constants, and the volume change of the reaction were obtained in the absence and in the presence of SDS. The micellar catalytic effects observed for methylamine was smaller than those for amines of long alkyl chain, which was ascribed to the facts that the former is incorporated into the micellar ionic atmosphere in the concentrated micellar solution while the latters are solubilized into micelles.

ChemInform Abstract: MICELLAR EFFECTS ON THE KINETICS OF THE PROTOLYSIS OF CARBOXYLIC ACIDS STUDIED BY THE ULTRASONIC ABSORPTION METHOD

Chemischer InformationsdienstVolume 16, Issue 8 Article ChemInform Abstract: MICELLAR EFFECTS ON THE KINETICS OF THE PROTOLYSIS OF CARBOXYLIC ACIDS STUDIED BY THE ULTRASONIC ABSORPTION METHOD S. HARADA, S. HARADASearch for more papers by this authorT. YAMASHITA, T. YAMASHITASearch for more papers by this authorH. YANO, H. YANOSearch for more papers by this authorN. HIGA, N. HIGASearch for more papers by this authorT. YASUNAGA, T. YASUNAGASearch for more papers by this author S. HARADA, S. HARADASearch for more papers by this authorT. YAMASHITA, T. YAMASHITASearch for more papers by this authorH. YANO, H. YANOSearch for more papers by this authorN. HIGA, N. HIGASearch for more papers by this authorT. YASUNAGA, T. YASUNAGASearch for more papers by this author First published: February 26, 1985 https://doi.org/10.1002/chin.198508077AboutPDF 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 Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume16, Issue8February 26, 1985 RelatedInformation

Micellar effects on the kinetics of the protolysis of carboxylic acids studied by the ultrasonic absorption method

Etude de la relaxation dans des solutions d'acide benzoique (et ses derives) en presence du chlorure de dodecylammonium. La relaxation est attribuee a la protolyse de l'acide carboxylique sur la surface de la micelle. Parametres cinetiques

Static and kinetic studies of the phase transition of bilayer membrane of dioctadecyldimethylammonium bromide

The gel-liquid crystal phase transition of the bilayer membrane of dioctadecyldimethylammonium bromide was studied statically by monitoring the turbidity, the volume, the conductivity, and the sound velocity of the aqueous solution. With decrease of the temperature, these physical properties changed very steeply at 40-39°C and the phase transition temperature T m was determined to be 39.5°C. When the temperature was raised, a hysterisis was observed and the value of T m was about 3°K higher. A decrease of the volume and increases of the conductivity and the compressibility observed at the phase transition from the liquid crystal to the gel indicated that a phase transition accompanies the dissociation of the counterion from the bilayer membrane. The kinetic studies by the pressure-jump method and the ultrasonic absorption method showed that the phase transition is composed by at least two processes, one is a nucleation and annihilation process with the time constant of the order of 10 −2 sec and the other is a growth and shrinking process on the order of 10 −9 sec. Both relaxation phenomena have maximum relaxation time and amplitude at around T m, which indicates that both processes are cooperative. Static and kinetic studies were also performed for the bilayer membranes of dimethyloctadecyldodecylammonium bromide and didodecyldimethylammonium bromide, but no evidence of the phase transition was observed. The pressure-jump relaxation observed in the time ranges of 10 −2 and 10 −3 sec, respectively, was ascribed to the monomer association and dissociation to and from the bilayer membrane.

Kinetic Studies of the Base Equilibrium of Secondary Amines on the Surface of Sodium Dodecyl Sulfate Micelle by Means of the Ultrasonic Absorption Method

Abstract The ultrasonic relaxation absorption has been measured in aqueous solution of dipentylamine, dihexylamine, dioctylamine, N-methylphenethylamine, and N-ethylbenzylamine in the presence of the sodium dodecyl sulfate(SDS) micelle. The relaxation absorption has been ascribed to the base equilibrium of the amines on the surface of the micelle: RR′NH2++OH−\oversetkf\undersetkb\ightleftharpoonsRR′NH+H2O. The rate constants γ±2kf, kb, the apparent base dissociation constant Kb (=kb⁄γ±2kf), and the volume change in the base equilibrium ΔV were obtained, where γ± is the mean activity coefficient for RR′NH2+ and OH−. The dependence of the rate constants on Kb revealed that, in the detailed mechanism of the base equilibrium of the amines, RR′\underset(I)NH2++OH−\oversetk12\undersetk21\ightleftharpoons(RR′NH\underset(II)2+···OH−)\oversetk23\undersetk32\ightleftharpoonsRR′N\underset(III)H+H2O, the rate-determining step is the proton-transfer process, (II) \ightleftharpoons (III). The pKb values of the secondary amines on the surface of the SDS micelle were 0.94–1.26 smaller than the corresponding values in the aqueous solution, and the micellar effect on pKb was smaller than that of the primary amines. From the standpoint of the micellar effect, the structures of the amines solubilized in the micelle were discussed.

Micellar effects on the kinetics of the hydrolysis of alkylamines studied by the ultrasonic absorption method

Hydrolyse de methyl-1 heptylamine, tetramethyl-1,1,3,3 butylamine, phenyl-4 butylamine, phenyl-3propylamine phenethylamine et benzylamine en presence de micelles de laurylsulfate de Na

Kinetic studies of the hydrolysis of n-octylamine on the surface of a sodium dodecyl sulfate micelle by the ultrasonic absorption method

Kinetic studies of the hydrolysis of n-octylamine on the surface of a sodium dodecyl sulfate micelle by the ultrasonic absorption method