File Name : figure s1.jpg

Caption : fig. s1 the schematic diagram of the cell setup for area resistance study

File Name : figure s2.jpg

Caption : fig. s2  the particle size analysis of (a) nano-silica particles, (b) sulfonated nano-silica particles

File Name : figure s3.jpg

Caption : fig. s3 the 1h nmr spectrum spva polymer

File Name : figure s4.jpg

Caption : fig. s4 the afm images of the spva-si composite membranes with (a) formaldehyde, (b) glutaraldehyde, (c) poly(styrene sulfonic acid-co-malic acid) (pssa-ma) and (d) tetraethyl orthosilicate (teos) crosslinkers

File Name : figure s5.jpg

Caption : fig. s5 tga and dsc thermograms of spva membrane

File Name : figure s6.jpg

Caption : fig. s6   the nyquist impedance studies of spva-si/pssa-ma and spva-si/teos crosslinked membranes at 80 °c.