Surface tension Jasper method

The surface tension has been measured for methyl ether near its critical point. for ethyl ether from OX to its critical point.and for propyl and butyl ether from 20X to 6tfX.M Jasper has tubulated the surface tension of ethyl ether from irC to 30X. for propyl ether from I5X to GOT. und butyl ether from I5T to 90°C. Sugden s method, used to estimate the surface tension over a wider temperature range, gave an average error of 5% when compared to eight experimental values. 

Hie International Critical Tables and Timmermans75 report surface tension data from 0Y to 60X for the compounds. Jasper reports duiu in the same temperature range.33 The data were extended over a wider temperature range by the method of Sugdcn.1... 

The surface tension of a liquid is a measure of its tendency to minimize its surface area. The models for surface tension found in the literature are built on thermodynamic approaches, and they relate surface tension to a number of other physical properties, or to combinations of them. However, the literature contains little concerning the effect of specific molecular features on surface tension and provides no method to calculate surface tension from molecular structure. A set of 146 values for surface tension at 30 °C was extracted from a paper by Jasper that reports values for more than 2200 pure compounds with diverse structures, often at several different temperatures and with an experimental error of approximately 0.10 dyn cm . The compounds were encoded using a variety of topological, geometric, and electronic descriptors. A model was developed for a combined set of alkanes, alkyl esters, and alkyl alcohols which utilized 10 descriptors and had s = 0.4 dyn cm (1.8% of the mean). This model was then used to predict the surface tensions for 20 compounds not used in model development. 

There exists an extremely useful compendium of published surface tensions of many (mainly organic) liquids, measured by various methods, at different temperatures (Jasper, 1972). These values are usually extremely reliable oiJy one error has been noted which is of some importance to the present... 

---