About the sensitivity of the small angle neutron scattering technique in the determination of a polymer interfacial density profile

(Received 3 August 1992, accepted in final form 2 November 1992)

Abstract
We have measured the small angle neutron scattering intensity for two samples consisting of deuterated poly(styrene) chains, grafted onto silica and immersed in a good solvent - so-called polymer brushes. Two different methods have been used : contrast matching and contrast variation. The data have been analyzed in terms of an interfacial density profile. Amongst the different forms tested, only the parabolic one has been found to agree satisfactorily with the data. Moreover, the technique is sufficiently sensitive to show that an exponential tail and eventually an adsorption layer should be added in order to obtain a "realistic" interfacial density profile.