Open AccessThe properties and molecular structure of thin films. Part III.―Expanded films
Author(s) -
N. K. Adam
Publication year - 1922
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1922.0063
Subject(s) - range (aeronautics) , atmospheric temperature range , thin film , materials science , molecule , chemistry , thermodynamics , chemical physics , nanotechnology , composite material , organic chemistry , physics
In the previous paper an account was given of the properties of the films over a range of temperature low enough for it to be permissible to regard the molecules as in direct contact over the whole area, except perhaps for a very slight tendency to separate under the lowest compressions; this tendency being perhaps analogous to vapour pressure. The films in this condensed condition were either solid or liquid. Within the accuracy of my experiments, the mechanical properties of condensed films were independent of temperature. The present paper describes the phenomena observed above this range of temperature. At a certain temperature all the films expand along the surface, the actual temperature of expansion depending both on the nature of the substance in the film, and on the composition of the solution. The phenomena exhibited by films of the fatty acids on dilute HCl have been the most thoroughly investigated, and will be first described.