Preparation of conductive composite hydrogels from carboxymethyl cellulose and polyaniline with a nontoxic crosslinking agent

Conductive composite hydrogels based on sodium carboxymethyl cellulose (CMC) and polyaniline (PAn) were prepared via the semi-interpenetrating polymer network (semi-IPN) method, using glycerol diglycidyl ether (GDE) as the crosslinking agent. The structures of the resulting composite hydrogels were characterized by 13C-NMR, FT-IR, and SEM. The composite hydrogels with various concentrations of CMC presented a similar swelling kinetic behaviour and a relatively high swelling ratio. With increasing CMC concentration, both the compressive fracture stress and modulus of the composite hydrogels improved gradually. Though the modulus of the composite hydrogels increased with more GDE added, the compressive fracture stress decreased when the crosslinking density was too high. The electrical conductivity of the composite hydrogels increased first and then decreased slightly with increasing dosages of CMC and GDE. Doping with aromatic sulfonate is a good approach to improve the conductivity of the composite hydrogels and the conductivity reached 6.31 × 10−3 S cm−1 after doping with sodium benzene sulfonate (BSNa).