Free radical decay and micro-structure evolution of PVDF membranes in situ irradiated by synchrotron radiation X-ray

The synchrotron radiation X-ray was used both as the irradiation source and testing tool for the PVDF membranes in-situ. The structural evolution of the PVDF membranes irradiated by the synchrotron radiation X-ray was analyzed by in-situ small angle X-ray scattering (SAXS)/wide angle X-ray scattering (WAXS) and ex-situ (ESR, FTIR and XRD) characterization methods. The alkyl radicals and carbon-carbon double bonds appeared in the irradiated PVDF membranes due to the irradiation effect, which confirmed that PVDF membranes first cracked, followed by cross-linked, during irradiation. The disappearance of the scattering peak at q = 0.05 angstrom(-1) indicated that the synchrotron radiation X-ray destroyed the long periodic structure. The X-ray irradiation destroyed the crystalline region of the irradiated PVDF membranes, thus, leading to a decline in the crystallinity. Thus, overall, the in-situ irradiation and analysis could effectively monitor the structural evolution of the PVDF membranes during the radiation process and reduce the influence of time intervals between irradiation and measurement.

Automated summary

Synchrotron radiation X-ray was used as both the irradiation source and testing tool for PVDF membranes. The structural evolution of the PVDF membranes under irradiation was analyzed using in-situ and ex-situ characterization methods. The study demonstrated that the synchrotron radiation X-ray destroyed the long periodic structure and crystalline region of the PVDF membranes, leading to a decline in crystallinity.