The physical origins of low surface tensions

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 monolayers collapse by solubilization into the subphase. Monolayers that retain a continuous LE phase network surrounding islands of LC or S phase collapse at lower surface tensions via a localized, large amplitude buckling. The buckled regions coexist with the flat monolayer, remain attached to the interface and are reversibly reincorporated into the monolayer upon expansion. Synthetic replacement surfactants must be designed to reproduce this unique phase behavior for optimal function