STRUCTURE OF CYCLOHEXANE t-BUTANOL MIXTURES FROM POSITRON ANNIHILATION AND ULTRASONIC VELOCITY MEASUREMENTS

The densities of and sound velocities in t-butyl alcohol solutions in cyclohexane were determined in the temperature range 25 to 45°C. From these data adiabatic compressibility coefficients of the solutions were calculated, as well as excess densities and compressibilities. The positron annihilation spectra of the solutions were measured at room temperature. The results plotted against alcohol concentration show structural processes, which can be attributed to dimerization of the solute molecules

Structure of Aqueous Solutions of 1,2- and 1,3-Propanediol Investigated by Positron Annihilation and Ultrasonic Methods

The structure of aqueous solutions of 1,2-propanediol and 1,3-propane-diol was investigated using adiabatic compressibility measurements and positron annihilation methods. The experimental results are different than those obtained earlier for systems where hydrophobic hydration dominates. There are some evidences for increased rigidity of the water network, which can arise from the formation of hydrogen bonds between diols and water

Structure of Carbon Tetrachloride + t-Butanol Mixtures from Positron Annihilation and Ultrasonic Velocity Measurements

The densities of and sound velocities in t-butyl alcohol solutions in CCl$\text{}_{4}$ were determined in temperature range 25 to 45°C. From these data the adiabatic compressibility coefficients of the solutions were calculated, as well as excess densities and compressibilities. The positron annihilation spectrum for this system in room temperature was measured. The results plotted against alcohol concentration suggest that the structural processes occurring in this system are caused by dimerization of the solute molecules

Structure of Cyclohexane + t-Butanol Mixtures from Positron Annihilation and Ultrasonic Velocity Measurements

The densities of and sound velocities in t-butyl alcohol solutions in cyclohexane were determined in the temperature range 25 to 45°C. From these data adiabatic compressibility coefficients of the solutions were calculated, as well as excess densities and compressibilities. The positron annihilation spectra of the solutions were measured at room temperature. The results plotted against alcohol concentration show structural processes, which can be attributed to dimerization of the solute molecules

Positron Annihilation in and Compressibility of Water-Organic Mixtures. The System Water-Acetamide

The experimental results of positron annihilation experiments in aqueous solutions of acetamide were compared to those of ultrasonic velocity. The system under investigation behaves untypically when changing acetamide concentration. From the point of view of surface tension it interacts with water like normal alcohols, while the positron annihilation and ultrasonic results suggest hydrophilic hydration and lack of hydrophobic interactions

Positron Annihilation in and Compressibility of Water-Organic Mixtures. The System Water-Formamide

The experimental results of positron annihilation experiments in aqueous solutions of formamide were compared to those of ultrasonic velocity. The systems under investigation behave untypically while changing formamide concentration. The results are explained in terms of hydrophilic hydration and lack of hydrophobic interactions

The role of hydrophobic interactions in structure of aqueous nonelectrolyte solutions from positron annihilation measurements

The experimental results of positron annihilation and sound velocity experiments in aqueous solutions of formamide and ethyl alcohol are compared. The concentration dependences of annihilation parameters and of adiabatic compressibility differ significantly for these systems, indicating hydrophobic hydration occuring in the case of water-alcohol system and hydrophilic one in the case of water-formamide

Annihilation of o-Positronium in the Vicinity of the Critical Mixing Point

Positron annihilation spectra were investigated in the critical region close to the consolute point of ethanol + dodecane mixture. The anomalies of the positron lifetimes and intensities were small, nevertheless it was found that the intensity of short-living components of annihilation spectrum seems to increase close to the critical temperature