Fig. 4: In situ rheo-SAXS/WAXS measurements of PEO crystallisation.
From: Flow-induced crystallisation of polymers from aqueous solution
Characterisation of flow-induced nucleation of 60% w/w PEO aqueous solution by in situ rheo-SAXS/WAXS technique. The images are 2D scattering patterns recorded after shearing the solution at \(\dot \gamma\) = 10 s−1 for various times at 25 °C. The flow direction is shown on the SAXS pattern of tp = 40 s. The upper and lower graphs show the dependence on shearing time of the total intensity of SAXS patterns and Hermans’s P2 orientation function (the anisotropy calculated from 2D SAXS patterns), respectively. The red dashed line indicates the shearing time required for PEO nucleation under the chosen shear rate which was calculated from Wc measured by SIPLI. Miller indexes assigned to WAXS pattern corresponding to tp = 100 s indicate positions of diffraction peaks associated with 72 helical PEO crystal structure (space group P21/a). q* and 2q* shown in the SAXS pattern corresponding to tp = 140 s indicate peak positions associated with the first and second order of lamellar morphology with the period of ~ 140 Å formed by oriented semi-crystalline PEO. Error bars indicate uncertainty associated with P2 calculations.
