Iw. Hamley et al., CRYSTAL THICKNESSES IN SEMICRYSTALLINE OXYETHYLENE OXYBUTYLENE BLOCK-COPOLYMERS BY ATOMIC-FORCE MICROSCOPY AND SAXS/, Polymer, 39(15), 1998, pp. 3321-3326
The structure of thin crystallized films of a diblock or a triblock co
polymer deposited on silicon has been investigated using atomic force
microscopy (AFM). Non-contact mode AFM was used to investigate the top
ography of crystallites of poly(oxyethylene)/poly(oxybutylene) (E/B) b
lock copolymers at room temperature, where E is crystallized and B is
amorphous. The crystal thicknesses determined from AFM were compared t
o bulk layer spacings determined using small-angle X-ray scattering (S
AXS). This technique showed that E41B22E41 (the subscript denotes the
number of repeat units) largely crystallized in a monolayer with unfol
ded E blocks at the substrate and folded (looped) B blocks at the poly
mer-air interface, and with the E blocks tilted at an angle of ca. 60
degrees relative to the substrate plane. Multiple layers with a common
step height were observed for the diblock E27B6 crystallites, which w
ere largely comprised of unfolded chains, also with E block tilted at
an angle of ca 60 degrees with respect to the substrate plane. (C) 199
8 Elsevier Science Ltd. All rights reserved.