Showing papers on "Miscibility published in 1972"

Solvent selection via miscibility number

Abstract: In formulating a mixed solvent or selecting a reaction medium, chemists have to deal with the phenomena of liquid miscibility. The author has collected and correlated a great amount of miscibility data; a typical portion of the master chart constructed from these data is illustrated. The liquids are arranged in an order that results in a stair-step arrangement of the boundaries between miscibility (m) and borderline-immiscibility (b). The hypothetical property that determines this order may be called lipophilicity, or affinity for oil-like substances. Finally the range between the extremes of low and high lipophilicity was partitioned into 31 classes, each composed of liquids showing the same miscibility relationships with other liquids. Assuming that the intervals between these miscibility classes are made as uniform as possible according to some logical criterion, the position of a class in the series should have quantitative significance as a measure of lipophilicity. This serial number is called the miscibility number, or M-number for short. A chart illustrating the relationship between the standard solvents (and the miscibility classes) is presented. An alphabetic list of organic liquids that have been given M-numbers also is shown. When applied to other pairs of liquids selected from the tabulr data,more » it leads to a high percentage of valid predictions.« less

Immiscibility in binary alloys of group IB metals (copper, silver and gold) ? a semi empirical approach

Abstract: The paper shows that concepts of neither the Hildebrand parameter nor the Mott number are adequate to predict the occurrence of miscibility gaps in binary metallic systems. It shows that modified versions of these parameters which are closely integrated with the structure of liquid metals (now called the Kumar-Hildebrand and the miscibility syndrome respectively), statistically account for the occurrence of miscibility gaps. Whereas no rigorous and theoretical justification could be given, it is shown that miscibility in liquid binary metallic systems could be discussed in terms of the electronic configuration of valency electrons.

Polymer miscibility in mixed organic liquids. An extension of the two‐dimensional approach

Abstract: Previous work on the two-dimensional approach to polymer miscibility in organic liquids is extended to polymer–mixed liquid system. From thermodynamic considerations methods for calculating δh of the mixed liquid and χH of the polymer–mixed liquid system from properties of pure components are proposed, where δh is the hydrogen-bonding solubility parameter of the liquid, and χH is a term which takes account of the dispersion and polar interactions between the liquid and the polymer and of effects due to temperature and molecular size of the liquid. Using these two calculated parameters, the solvent power of the mixed liquid can be determined from its location on the χ plane.

Immiscibility in binary alloys of group IA metals (lithium, sodium and potassium)

Abstract: This paper evaluates the miscibility syndrome in order to predict the occurrence of miscibility gaps in the binary alloy systems of lithium, sodium, and potassium and compares its predictions with those from the Hildebrand, the Kumar-Hildebrand parameters or the concept of Mott number. It is shown that statistically, the predictions from the miscibility syndrome are most reliable. An attempt is also made to partially rationalize the nature of the binary liquid systems in terms of the electronic configuration of the valency electrons.