Preparation of a carboxymethylated bacterial cellulose/polyaniline composite gel membrane and its characterization

Abstract

Bacterial cellulose (BC) was modified by carboxymethylation (CM) to get carboxymethylation bacterial cellulose (CM-BC) with different degrees of substitution (DS). Then the novel conductive CM-BC/PANI nanocomposite membranes were successfully synthesized in situ by oxidative polymerization of aniline using CM-BC as the template. The influence of carboxymethylation on the structure, morphology, electrical/proton conductivity and mechanical property of the CM-BC/PANI composites has been investigated. The CM-BC/PANI networks display a combination of hybrid electronic/proton conductivity and better mechanical property compared to that of BC/PANI. The electrical conductivity can reach 1.69 × 10⁻² S cm⁻¹ when the DS is 0.146 with carboxymethylation for 13 hours. In addition, the proton conductivity of CM-BC/PANI shows an obvious improvement in comparison to that of BC/PANI, which could reach 2.86 × 10⁻⁴ S cm⁻¹. The CM-BC/PANI composite membranes exhibit certain flexibility and good mechanical properties with a tensile strength of 0.23 MPa.