Understanding near surface polymer dynamics: neutron and virtual experiments

Neutron spin-echo spectroscopy is a unique experimental method for an investigation of the polymer dynamics. The combination of neutron spin-echo spectroscopy with grazing incidence geometry (GINSES) opens the possibility to probe dynamics of the soft matter materials in the vicinity to the solid substrate in the time range up to 100 ns. However, the usage of the GINSES technique has some peculiarities and, due to the novelty of the method and complexity of the scattering geometry, difficulties in further data analysis appear. In the current work we discuss how virtual experiments within the distorted wave Born approximation (DWBA) with the BornAgain software can improve the GINSES data treatment and help to understand the polymer dynamics in the vicinity to the solid surface. Dynamics analysis using combination of neutron and virtual experiment are presented on example of polymer brushes with grafting densities in the concentrated and semidilute regime.