Abstract
Model studies of foams and single foam films under close and defined conditions are employed to study the effect of the isoelectric state (pH ∗) at the solution/air inteface on the stability (lifetime) of foams from tetraethyleneglycol monodecyl ether C 10(EO) 4 and eicosaoxyethylene nonylphenol ether, NP20. The parameter pH ∗ and the potential of the diffuse electric layer Φ o are found by the method of the equilibrium foam film. A metastable zone in which films are both equilibrium and rupturing, is established to appear pH values higher than pH ∗. Isotherms of disjoining pressure II( h) are measured for the first time at different pH and its influence on the interaction forces in the foam film is revealed. At constant solution ionic strength the pH change affects strongly the pressure at which films rupture. However, at equal ionic strength and surfactant concentration, the stability of foams dramatically decreases when pH ∗ is reached.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Colloids and Surfaces A: Physicochemical and Engineering Aspects
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
