Relaxation and equilibrium properties of dilute aqueous solutions of alcohols

Qualitative Analysis of Clustering in Aqueous Alcohol Solutions. II

“…As a result, there are on average 12-13 water molecules per one ethanol molecule. As was shown in works [3,14], the uniform distribution of water molecules over the monolayers is thermodynamically unstable. Therefore, concentration fluctuations grow at the singular point, and there emerges a microscopically heterogeneous structure of the solution [4,14,15,19,20].…”

“…It is well known that the properties of aqueous solutions of monoatomic alcohols differ drastically from the properties of ideal solutions [1][2][3]. This difference manifests itself in such physical properties as the intensity of molecular light scattering in a vicinity of the singular point of the solution [4][5][6], adiabatic compressibility [7], and heat capacity [8], in the emergence of anomalously large relaxation times [3,9], and even in the behavior of the simplest thermodynamic parameter of the system, its contraction (a decrease in the volume at the solution formation) [10][11][12][13][14]. From the standpoint of the theory of molecular structure, all those and other peculiarities in the behavior of solutions [15] are a result of clustering processes running in them.…”

“…Under the conditions corresponding to the singular point of the aqueous ethanol solution, every alcohol molecule in the solution is surrounded by 25-26 water molecules, so that there are no unbound water molecules at all (see works [3,14]). In effect, there arises an ensemble of elementary clusters consisting of ethanol molecules and a monolayer of water molecules taken in the above-mentioned ratio.…”

Qualitative Analysis of Clustering in Aqueous Alcohol Solutions

“…The properties of aqueous monohydric alcohol solutions differ substantially from the properties of ideal solutions [1][2][3]. This difference reveals itself in the optical properties of solutions, in particular, in the appearance of maxima in the abnormal light scattering [4][5][6], in the form of the concentration and temperature dependences of the adiabatic compressibility [7] and the heat capacity [8], in the emergence of large relaxation times [2,9] and other features in the volumetric behavior of those solutions [10,11], in particular, their contraction [12][13][14].…”

Anomalous Light Scattering in Aqueous KCl Solutions

“…Taking the experience of other researchers [12,13] into ac-count, as well as our own experience obtained from the previous works with aqueous alcohol solutions [10,[14][15][16], the specimens obtained after the salt dissolution were settled for several days. Before the measurement, the specimens were held at the measurement temperature for several hours until the steady MLS intensity was reached.…”