Sh. Anastasiadis et al., ON THE INTERFACIAL WIDTH IN TRIBLOCK VERSUS DIBLOCK COPOLYMERS - A NEUTRON REFLECTIVITY INVESTIGATION, Macromolecules, 31(19), 1998, pp. 6600-6604
The relationship between the interfacial width in a lamellar triblock
copolymer and that in the respective lamellar diblock has been investi
gated by neutron reflectivity, taking advantage of the surface-induced
orientation of the domains parallel to the free surface in thin copol
ymer films. The effective interfacial width in a nyl-2-pyridine)-polys
tyrene-poly(vinyl-2-pyridine) triblock is found to be similar to 38% n
arrower than that for the respective diblock. This difference is discu
ssed in relation to theoretical predictions and is tentatively attribu
ted to a reduced contribution of the thermal fluctuations of the conce
ntration profiles to the effective interfacial width because of the pr
esence of the mid-block bridges connecting the end-block domains in th
e triblock lamellae.