Combining theory and experiment for X-ray absorption spectroscopy and resonant X-ray scattering characterization of polymers

Abstract

An improved understanding of fundamental chemistry, electronic structure, morphology, and dynamics in polymers and soft materials requires advanced characterization techniques that are amenable to in situ and in operando studies. Soft X-ray methods are especially useful in their ability to non-destructively provide material or chemical moiety specific information. Analysis of these experiments, which can be very dependent on X-ray energy and polarization, can quickly become complex. Complementary modeling and predictive capabilities are required to properly probe these critical features. Here, we present relevant background on this emerging suite of techniques. We focus on how the combination of theory and experiment has been applied and can be further developed to drive our understanding of how these methods probe relevant chemistry, structure, and dynamics in soft materials.

Quantitative Morphology–Performance Correlations in Organic Solar Cells: Insights from Soft X‐Ray Scattering

“…Directly extracting information about absolute domain purity from R-SoXS measurements is foreseen to be very valuable for OPVs, and in other fields related to polymer/organic blends. In addition to the successful application in the OPV field, these soft X-ray scattering techniques has been also applied in probing the morphology of various polymers, [58,153] thermoelectric molecules, [154] liquid crystals, [155] and perovskites. [156] The quantitative correlations established in OPV materials will vastly reduce the parameter space of the trial-and-error synthesis and optimization approach by clearly delineating why a particular set of materials and processing condition might fail or which aspect may need to be improved.…”

Multi-level chirality in liquid crystals formed by achiral molecules

“…The phase structure exhibited by the studied nonsymmetric dimers was resolved by a resonant X-ray scattering (RSoXS). In contrast to nonresonant X-ray diffraction which is sensitive only to the electron density modulations, RSoXS also detects the periodic spatial variation of the orientation of molecules 20 . In our studies, we used RSoXS at the carbon absorption K-edge; this experimental method requires a very low-energy beam (~284 eV), but is universal, as carbon atoms are present in every organic molecule.…”

Chemical and Morphological Origins of Improved Ion Conductivity in Perfluoro Ionene Chain Extended Ionomers

“…Resonant soft X-ray scattering (RSoXS) has recently seen widespread use in many carbon-based materials such as carbon nanotubes, 27 liquid crystals, [28][29][30] proteins, 31,32 and polymers. [33][34][35][36][37][38] To date, RXS has not been applied to PFSA ionomers. Here, we showcase RXS at energies near the sulfur K-edge, around 2470 eV, which is ideal for studying proton-conducting ionomers for several reasons.…”