Carboxymethyl Cellulose (CMC) as a template for laccase-assisted oxidation of aniline

Abstract

Polyaniline (PANi) is a conducting polymer which has been subject of intensive research on the exploitation of new products and applications. The main aim of the work is the development of a conductive bacterial cellulose (BC)-based material by enzymatic-assisted polymerization of aniline. For this, we study the role of carboxymethyl cellulose (CMC) as a template for the in situ polymerization of aniline. Bacterial cellulose was used as the supporting material for the entrapment of CMC and for the in situ oxidation reactions. The amount of CMC entrapped inside BC was optimized as well as the conditions for laccase-assisted oxidation of aniline. The new oligomers were evaluated by spectrometric techniques, namely 1H NMR and MALDI-TOF, and the functionalized BC surfaces were analyzed by thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), and reflectance spectrophotometry. The conductivity of the developed materials was evaluated using the four-probe methodology. The oligomers obtained after reaction in the presence of CMC as template display a similar structure as when the reaction is conducted only in BC. Though, after oxidation in the presence of this template, the amount of oligomers entrapped inside BC/CMC is considerably higher conferring to the material greater electrical conductivity and coloration. The use of CMC as a template for aniline oxidation on BC seems to be a promising and cheap strategy to improve the yield of functionalization and increment the properties of the materials, namely electrical conductivity and coloration.