Langmuir, Vol.20, No.11, 4480-4488, 2004
Detailed modeling of the volume fraction profile of adsorbed polymer layers using small-angle neutron scattering
A detailed analysis of on and off-contrast small-angle neutron scattering from poly(ethylene oxide)s adsorbed on polystyrene latex is presented. The results have been fitted to an exponential decay, self-consistent mean-field (SCF) and scaling models of the volume fraction profile. As the chain length increases a clear self-similar layer emerges in both the SCF and scaling profiles. The RMS thickness of the adsorbed layer in the plateau of the adsorption isotherm varies as MO A for both the SCF and scaling profiles but the exponential one however gives a much lower exponent consistent with the neglect of the tail or distal region. The new constrained version of the Scheutjens-Fleer model was able to predict the structure of the layer and hence the scattering with great accuracy.