Electroactive hydrogels were prepared using commercial citric pectin, either raw (PC) or purified through
dialysis (dPC), and chemically synthesized polypyrrole (PPy). 1H NMR analyses showed that PC is a low
methoxyl pectin (degree of methoxylation, DM = 46%) and dPC is a high methoxyl pectin (DM = 77%). The
pyrrole polymerization was monitored through UV–vis spectroscopy and both samples were observed
to be good stabilizers for PPy in aqueous medium. The dispersions were used to prepare the hydrogels
h-PC-PPy and h-dPC-PPy. The hydrogel h-dPC-PPy has a higher swelling index (SI ≈ 25%) at pH 1.2 than
the hydrogel h-PC-PPy (SI ≈ 7%). Contrastingly, at pH 6.8 both hydrogels lost their mechanical integrity.
Raman spectroscopy revealed that PPy is more oxidized in h-PC-PPy. Nevertheless, both hydrogels are
electroactive and therefore can be considered for applications in which the control of the degree of
swelling is desired.