INSTANTANEOUS AND TIME-LAG BREAKING OF A 2-DIMENSIONAL SOLID ROD UNDER A BENDING STRESS

In a Langmuir monolayer of NBD-stearic acid, long rods (approximately 1 mm long, approximately 20 mum wide) of a two-dimensional solid phase are obtained at the liquid-solid phase transition. A rod bent in the plane of the water under the effect of a bending stress breaks after a clearly defined delay. This delay is a function of the strain applied to the rod and of the temperature. For large deformations, a second m ode of breaking appears and coexists with the previous one: A fraction of the rods break instantaneously while others break after a delay.