Neutron reflectometry studies on the interfacial width between polystyreneand various poly(alkylmethacrylates)

From neutron reflectometry we have obtained the interfacial width (typicall y 2-8 nm) between incompatible polymers above the glass transition temperat ures. The investigated polymer bilayers consist of a deuterated polystyrene top layer and various poly(alkylmethacrylates) as a bottom layer. We obtai ned interesting effects of the length of the alkyl group on the interfacial width. Using mean-field theory we calculate Flory-Huggins-Stavermann inter action parameters chi from the interfacial width alpha(1) data. These resul ts are compared with investigations of the interfacial width between deuter ated poly(methylmethacrylate) and respective polyalkylmethacrylates.