The thermal composition fluctuations of a deuterogenous polystyrene/polyethyleneoxide (dPS/PEO) homopolymer blend and corresponding diblock copolymer have been investigated by small angle neutron scattering (SANS). The measured susceptibilities could be described by theories, which take strong fluctuations into account. The yielded Ginzburg number is a measure of the deviation from mean field behaviour, and thus can be used to determine the mean field Flory-Huggins interaction parameter from phase boundary measurements. (C) 2000 Elsevier Science B.V. All rights reserved.
Physica B: Condensed Matter, 2000, Vol 276-278, p. 375-376