Formation of Clusters in 1‐Propanol/Water‐Mixtures

Abstract

and SFB 123, Im Neuenheimer Feld 256, 6900 Heidelberg Cluster-Bildung / Flhsigkeiten / Lichtstreuung Very sensitive and accurate elastic light scattering (LS) measurements have been carried out on mixtures of water with methanol, ethanol, 1-propanol and 2-propanol. Methanol showed no particular effect, while ethanol, 2-propanol and 1-propanol showed signs of increasing cluster formation at a composition of 1 alcohol molecule to 5 water molecules. For the mixture of 1-propanol with water, additional measurements of the quasielastic light scattering have been made and the hydrodynamic radii of the clusters have been calculated. This led to the suggestion of a cluster consisting of 8 1-propanol molecules and a solvation envelope of about 40 water molecules. The concentration of this cluster was determined by elastic LS to be 83% of the total solution weight at 25 "C and a composition of 40% by weight 1-propanol in water. The clusters appear to be rather stable, as the hydrodynamic radius showed no significant variation with temperature in the 5" to 50°C range. The concentration was however temperature dependent, as could be shown with elastic LS.

The Influence of Adsorbed Solvent (Lyospheres) on the Stability of Colloids

“…Perhaps the jelly-like surface of the polystyrene particles promotes the formation of 1-propanol/water envelopes with approximately one mole 1-propanol and four mole water in composition. The composition of the lyospheres is very close to the value which was detected for cluster structures in binary 1-propanol/water mixtures [5]. By a simple model ( Fig.…”

“…In mixtures of organic liquids with water, the organic molecules often have a tendency to aggregate with one another or tend to associate with water molecules in clusters. For instance, mixtures of 1-propanol or its longer-chained homologues with water can form micellelike structures of well-defined composition [5].…”

The Influence of the Composition of Binary Liquid Mixtures on the Electrophoretic Coefficient: Experimental Study on a Polystyrene Model Colloid

“…Subsequently, adsorption of water on the surface might increase rapidly due to the very hydrophilic surface that is produced by the high surface density of hydroxyl groups from adsorbed alcohol molecules. Grossmann and Ebert [21] have found that ethanol and 1-propanol show signs of increasing cluster formation at a composition of 1 alcohol molecule to 5 water molecules. For the mixture 1-propanol-water the cluster is formed by 8 1-propanol molecules and a solvation envelope of about 40 water molecules.…”

The Influence of Monomers upon Microemulsions with Short Chain Cosurfactant

“…This assumption seems to be correct: the highest (d 1 7 d 2 ) difference was noted in ACN and EtA, the monomers that give the maximum number of homogeneous samples (Fig. Nanostructuring occurs (owing to the``hydrophobic demixtion'') (5), followed by formation of zones with higher local concentration of hydrocarbon chains (6,8). Styrene, which is solubilized in a reduced number of systems, yields the lowest difference.…”