On the nature of morphological features in phase-separated (PEO)nNaSCN mixtures: a SAXS investigation

Abstract The SAXS technique is used to throw light on the morphology of phase-separated poly(ethylene oxide)n–sodium thiocyanate [(PEO)nNaSCN] mixtures. A temperature-dependent investigation is reported for (PEO)4.5NaSCN. (PEO)nNaSCN mixtures show a complex phase behaviour. At the investigated composition, a crystalline complex (CC) is formed between PEO and NaSCN. The considered composition is representative of thermodynamic states where three different phases coexist simultaneously: crystalline PEO (CPEO), amorphous PEO (APEO) and crystalline complex (CC). Various SAXS data analysis approaches are presented to understand the nature of these coexisting phases. Invariant analysis shows a bi…