ANALYSIS OF POLY(ETHYLENE-TEREPHTHALATE) (PET) FILMS BY ATOMIC-FORCE MICROSCOPY

An atomic force microscope operating in a contact mode can provide 5- x 5-nm atomic-scale images of a poly(ethylene terephthalate) (PET) fil m that allows the identification of what are believed to be phenyl gro ups and phenyl chains. Large-scale, 5- x 5-mu m images reveal the pres ence of raised surface features attributed to the extrusion process us ed to form the PET film. These surface irregularities could affect the film's physicochemical properties. Furthermore, regions with differen t overall surface roughnesses have been identified, showing that surfa ce roughness can distinguish between the amorphous and crystalline reg ions that form this type of film. Imaging forces have been found capab le of altering the film surface, and surface disorder increases with i maging time. (C) 1997 John Wiley & Sons, Inc.