Controlling nucleation in quasi-two-dimensional Langmuir poly(L-lactide) films through variation of the rate of compression

ABSTRACT: We studied morphological changes in a quasi-
two-dimensional Langmuir film of low molar mass poly(L-
lactide) upon increasing the surface density, starting from
randomly distributed molecules to a homogeneous monolayer
of closely packed molecules, followed by nucleation and growth
of mesoscopic, three-dimensional clusters from an overcom-
pressed monolayer. The corresponding nucleation density of
mesoscopic clusters within the monolayer can be tailored
through variation of the rate of compression. For a given surface
density and temperature, the nucleation probability was found
to increase linearly with the rate of compression, allowing to adjust the density of mesoscopic clusters over nearly 2 orders of
magnitude.