Temperature effects on alcohol aggregation phenomena and phase behavior in n-butanol aqueous solution

Molecular Aggregation Behavior and Microscopic Heterogeneity in Binary Osmolyte–Water Solutions

“…As the temperature increases, the self-associated butanol aggregates change into spatially extended H-bond aggregates that interact substantially with water. The expansion of the network-like butanol aggregates allows for coexistence with the water H-bond network, leading to the formation of a single-phase solution. , …”

“…As shown in the eigenvalue spectrum of osmolyte aggregates in Figure , the spectrum pattern reflects the osmolyte aggregation behavior in the binary mixtures. In the extreme case where all the osmolyte molecules are perfectly isolated ignoring osmolyte–osmolyte interaction, the eigenvalue should be 0, and for the aggregate in which two osmolyte molecules associate, the eigenvalue is assigned as ±1. ,, Discrete peaks appear with the formation of variously sized small aggregates, and the eigenvalue spectrum becomes broad and continuous as huge osmolyte aggregates are formed. As expected, the eigenvalue spectrum of TMU is comparatively wide and continuous in the existence of large osmolyte aggregates, but the peaks of TMAO appear discrete, with strong peak intensities at 0 and ±1, representing a high population of monomers and dimers.…”

“…Meanwhile, by employing the combination of MD simulation and graph theory, the aggregation behavior of solute and water molecules has been examined with the calculation of network properties of molecular aggregates in a wide range of binary mixtures of water including salts, − osmolytes, ,, alcohols, − and so on. − Sundar et al conducted a detailed analysis, calculating the radial distribution function (RDF) and graph theoretical properties of the H-bond network of solution in various osmolyte–water mixtures . The results indicate that the local solvation structure and overall H-bond network properties in urea and glycerol solutions are similar regardless of the nature of the osmolyte, whether it is a denaturant or stabilizer.…”

“…In various concentrated aqueous solutions, a solvation-induced molecular aggregation pathway has recently been proposed in use of a combination of MD simulation and graph theoretical analysis, which reveals formation of distinct molecular aggregates, categorized as either self-associated or spatially extended, depending on their interactions with water. ,,,, For example, the primary alcohols of methanol and ethanol, which have a short carbon chain, form spatially extended alcohol aggregates while retaining the interactions with water, but the n -butanol prefers to form self-associated aggregates to avoid interaction with water due to their relatively long carbon chain. These two types of alcohol aggregates possess distinct morphologies in their respective graphs and have varying effects on the water H-bond structure and phase behavior in the binary alcohol–water mixtures.…”

2-Butanol Aqueous Solutions: A Combined Molecular Dynamics and Small/Wide-Angle X-ray Scattering Study

“…The alcohol aqueous solutions are widely studied for their specific properties and applications in numerous research, technological, and medical sectors. − …”