TRANSFER OF AIR THROUGH ADSORBED SURFACE FILMS AS A FACTOR IN FOAM STABILITY.
Abstract
A method was developed for the direct determination of the rate with which single bubbles, floating at the surface of detergent solutions, lose air to the atmosphere because of the pressure gradient set up in the film by the higher pressure of the air in the bubble. The rate of decrease of bubble radius with time may be used as a direct measure of the permeability of the surface film to air, or a 'permeability' constant may be calculated. Low permeability is associated with high stability foams, whereas solutions yielding foams of poor stability show very high permeability to air for the adsorbed surface film. Factors affecting the interpretation of the permeability data are discussed. Both permeability and surface viscosity appear to depend on the coherence developed in the surface film, but the quantitative dependence appears to be different in the two cases. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1949
- Accession Number
- AD0625344
Entities
People
- A. G. Brown
- J. W. Mcbain
- W. C. Thuman
Organizations
- SRI International