Aztec 3

Cross-sectional imaging and elemental analysis of the corrosion products and biofilms were done by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). One coupon was extracted from each reactor on day 40 and immediately placed in a glass cell for drying under nitrogen flow for 5 days. Subsequently, coupons were mounted in Epofix resin and one of the sides was dry polished to reveal the cross-sectional profile. Samples were coated with a platinum layer (5 nm thick), and surface analysis was performed using a Zeiss Neon high-resolution scanning electron microscope. Images were collected using 20 kV and the backscatter detector. Aztec 3.0 software (Oxford Instruments NanoAnalysis) was used for the data analysis.

Electrospun fibers’ surface morphology among membrane groups was analyzed before and after tBOC treatment by SEM (NOVA NanoSEM 650, FEI Company, Hillsboro, OR, USA) and EDS analysis (Oxford Instruments NanoAnalysis, USA). Membranes were attached to a SEM stub with double-sided, conductive tape and sputter-coated with 5 nm gold-palladium.
Images were taken between 500× and 5000× magnification. Images of three sample locations per membrane and 20 fiber measurements per representative image of the membrane were taken to determine the uniformity of fiber morphology and average fiber diameter. Fiber analysis was conducted using ImageJ-Fiji analysis software, an open source plugin package for ImageJ. software (Fiji: version 2.9.0, developer(s): J. Schindelin et al., https://fiji.sc/; Image-J: National Institutes of Health, Madison, WI, USA).
EDS data was collected to determine TFA salt removal from spun membranes before and after the tBOC treatment via the F-peak. EDS was also used to determine MgP incorporation via the detection of the magnesium and phosphorus peaks. Spectra were analyzed via Aztec 3.0 software (Oxford Instruments, Abington, UK).