CS	chitosan
PEM	proton exchange membrane
sCS	sulfonated chitosan
MFC	microbial fuel cell
PVDF	polyvinylidiene fluoride
PS	1,3-propane sultone
fSiO2	functionalized silicone dioxide
FTIR	Fourier transform infrared spectroscopy
XRD	X-ray diffraction
λ	wavelength
FE-SEM	field emission scanning electron microscopy
TGA	thermogravimetric analysis
AFM	atomic force microscopy
TS	tensile strength
EAB	elongation at break
ASTM	American society for testing materials
WU	water uptake
SR	swelling ratio
IEC	ion-exchange capacity
σ	proton conductivity