Testing the Langer–Bar-on–Miller–Akcasu equation for the time evolution of the structure factor during polymeric spinodal decomposition and dissolution

Thermally induced spinodal decomposition and dissolution offer a route between miscible and immiscible microstructures in polymer blends, affecting the properties of the resulting material. Information about the microstructure can be deduced from measurements of the structure factor obtained using small-angle scattering. To aid with the analysis and modeling of polymeric scattering data, Akcasu et al. derived an equation of motion for the time evolution of the structure factor, which can be applied to both spinodal decomposition and dissolution. We refer to this equation as the LBMA equation. There is very little literature aimed at testing the LBMA equation. To rectify this, we tested the LBMA equation using synthetic structure factor snapshots derived from simulations. In the case of dissolution, the LBMA equation performed well at describing the time evolution of the synthetic structure factor snapshots. In the case of spinodal decomposition, we determined that improvements are required. We hope our findings motivate further experimental testing and modeling work.