A rapid approach to determine structure in multicomponent polymer thin films with resonant soft X-ray scattering

Resonant soft X-ray scattering (RSoXS) is a particularly powerful tool for soft material characterization. Because contrast is based on the functional groups and elements in the system, subtle differences between molecules create significant contrast in RSoXS without radiolabeling. RSoXS provides access to rich, hyperspectral scattering data, but interpretation of that data becomes prohibitively complex and time intensive as the number of components in the system increases. We have developed a contrast variation approach that takes advantage of the energy-dependence of the material dielectric functions, analogous to contrast variation in small angle neutron scattering, to overcome this complexity. Here, we present our CV-RSoXS analysis of poly(isoprene-block-styrene-2-vinyl pyridine) triblock copolymer thin films, which exhibit rich morphological variations depending on their processing history. We deconvolute the hyperspectral data into partial scattering functions, describing the spatial distribution of the individual components, which are then compared to forward simulations. This technique greatly simplifies analysis and is readily extendable beyond three-component systems, opening the possibility for label-free characterization of a wide range of multicomponent systems that are inaccessible with conventional tools.