Structures of water and primary alcohol studied by microwave dielectric analyses

Abstract

By the use of the time domain reflectometry method dielectric measurements were carried out first on methanol mixtures with ethanol and 1-propanol, and second, water mixtures with methanol, ethanol and 1-propanol in the frequency range 10 MHz–20 GHz. The first mixtures show a Debye relaxation and logarithm of the relaxation time is given by a linear function of the mole fraction of methanol. These mixtures have the same chainlike cluster of pure alcohol. The second mixtures show the same trend of the relaxation time in a region 0≤xw<0.83, where xw is the mole fraction of water. In a region 0.83<xw≤1.0, we observe an entirely different behavior, which indicates that the cluster of pure water appears for xw>0.83 and that the cluster must be cyclic, consisting of six molecules.

High Frequency Spectroscopic Study of the Bound State of Water in PEG-H2O System during Heating from Frozen State

“…14 Various changes in solution structure have been reported in the measurements of X-ray diffraction, 15 mass analysis, 16,17 NMR, [18][19][20] Raman scattering, 21 and time-domain reflectmetry (TDR). 22 The results obtained by these measurements are basically in good agreement with those obtained by HFS study. Consequently, HFS is useful for studying the changes of bound condition of water in the polymer-water mixtures.…”

Ab initio molecular dynamics study of aqueous solvation of ethanol and ethylene

“…Mixtures of water and ethanol have been studied extensively, both experimentally as by molecular simulation. Experimental studies employing NMR [13,14,15,16,17], ultrasonic absorption [18], infrared absorption spectroscopy [14,15,19,20], mass spectroscopy [19,21], X-ray diffraction measurements [19,22], neutron diffraction [22,23,24], and dielectric relaxation measurements [25,26,27,28] have been performed to unravel the solvation properties of ethanol. Molecular simulation studies using empirical force fields have addressed the equation of state, thermodynamics, and structure and dynamics of solvation [29,30,31,32,33] of aqueous ethanol solutions.…”

An Innovative Technique of Liquid Purity Analysis and Its Application to Analysis of Water Concentration in Alcohol-Water Mixtures and Studies on Change of Activation Energies of the Mixtures

“…4, No. 4; According to the previous investigations (Nagasawa et al, 2003) on the micro-viscosity of water-alcohol binary solvents (keeping water volume fixed and varying alcohol volume in the solution), the formation of the alcohol clusters caged inside the H-bond network of water molecules increases the bulk viscosity at alcohol mole fraction in the range of X A ≤0.2 (Roney, Space, Castner, Napoleon, & Moore, 1991;Mashimo, Umechara, & Redlin, 1991). In the range of X A ≥0.3, alcohol clusters start to gather and break the 'clathrate-like' structure, leading to lowering of bulk viscosity with higher alcohol fraction.…”