The ordering process and kinetics in thin films (200-800-mn thick) of a the
rmotropic side-chain liquid-crystalline polymer have been investigated vert
ically and laterally, respectively, by x-ray reflectivity and atomic-force
microscopy. The original smooth and amorphous spin-coated films initially b
ecome corrugated upon annealing in the smectic mesophase. The roughening of
the surface results from the formation of randomly oriented microcrystalli
ne domains in the film. At the same time, however, a laterally macroscopic
crystal starts to grow from the substrate surface in the direction of the p
olymer-air interface at the expense of these domain structures. Finally, a
nicely ordered single crystal with parallel-ordered bilayers is formed in t
he film as well as at the polymer-air interface. This one-dimensional cryst
allization, actually recrystallization, depends strongly on the temperature
due to viscosity effects. At low temperatures, just above the glass-transi
tion temperature, the ordering is very slow, belt with increasing temperatu
re the crystal growth is faster. An Arrhenius-type plot gives an activation
energy of 122 kJ/mol, which we ascribe to the expected reorientations of t
he mesogenic groups during the recrystallization process. [S1063-651X(99)08
109-4].