The minimum surface tension and respreadability of a surfactant monolayer is limited by a two to three dimensional instability called collapse. Liquid-condensed or solid phase monolayers collapse via fracture followed by loss of material. Liquid-expanded phase monolayers collapse by solubilization into the subphase. Monolayers that retain a continuous liquid-expanded phase network surrounding islands of liquid-condensed or solid phase collapse at low surface tensions via a localized, large amplitude buckling. The buckled regions coexist with the flat monolayer, remain attached to the interface, and reversibly reincorporate into the monolayer upon expansion.
Copyright 2017 Elsevier B.V., All rights reserved.