New polyaniline/porous glass composite

In this work we report the preparation of a glass-polymer composite, obtained by the in situ oxidative polymerization of aniline, in the pores of Porous Vycor Glass (PVG). A piece of PVG was added to acid aniline solution. PVG adsorbs aniline via an ion-exchange process (H+ from PVG porous surface/C6H5NH3+). The impregnated PVG was added to a (NH4)2S2O8 acid solution. The glass gradually went to dark green with the formation of polyaniline in its conducting form, the emeraldine salt. The counter-anions are the SiO− groups on the pores surface of the glass, as confirmed by 29Si-CP-MAS-NMR. Addition of the composite to an NH4OH solution leads do a change from dark green to dark blue (emeraldine base), and this process is reversible.