A combination of optical and atomic force microscopy (AFM) is used for prob
ing changes in the morphology of polymer blend films that accompany phase o
rdering processes (phase separation and crystallization), The phase separat
ion morphology of a "model" semi-crystalline (polyethyleneoxide or PEG) and
amorphous (polymethylmethacrylate or PMMA) polymer blend film is compared
to previous observations on binary amorphous polymer blend films of polysty
rene (PS) and polyvinylmethylether (PVME). The phase separation patterns ar
e found to be similar except that crystallization of the film at high PEO c
oncentrations obscures the observation of phase separation. The influence o
f film defects (e.g., scratches) and clay filler particles on the structure
of the semi-crystalline and amorphous polymer films is also investigated.