4. SEM/EDS analysis
The morphology of the fibrous membrane was observed with
a scanning electron microscope SEM (Philips XL30, Eindhoven,
and Netherlands). All of the samples were coated with gold (Au)
using spraying, high vacuum and 40 kV accelerating voltage. Ion
contents were measured from five spots, and the average was
measured. The energy-dispersive X-ray spectroscopy (EDS) microanalysis
(FEI Quanta 200 ESEM equipped with an EDX EDS device)
was also used to verify the accuracy of the experimental results;
the nanofibre diameter (SDnanofibre diameter = 5 nm) measurements
were performed two times and the typical standard deviation was
3–5 nm