Theoretical considerations on permeability have attracted the attention of many able and distinguished physicists and chemists during the last decade. More particularly has this been so “with the advent of increased activity in the field of high polymer chemistry. Typical examples of such work can be found in the extensive survey of membranes and permeability problems in a series of papers by Mane-gold, Adam, Langmuir, Kline, Hober, Brabender, Browne and others. Such research has involved highly theoretical thought and complicated methods of study, involving innumerable assumptions that required advanced technique and equipment to establish their validity. Today, a large portion of this work remains still to be correlated. But the picture as a whole has been slowly and steadily clarified by means of a more fundamental study of the nature of polymeric films.
The term permeability must not be confused with porosity; inasmuch as a micro-porosity, while it could in...
