Electro-responsive Polythiophene/Carboxymethyl Cellulose Smart Hydrogels

Abstract

In this study, the conductive polythiophene/carboxymethyl cellulose (PTh/CMC) hydrogels were prepared. Polythiophene (PTh) was synthesized via chemical oxidative polymerization method by using ferric chloride (FeCl₃) as oxidizer.  Monomer to oxidizer ratio and reaction time on electrical conductivity of PTh were investigated. The results showed that highest electrical conductivity (247.4432 ± 0.3569 S/cm) of PTh was found at the monomer to oxidizer ratio equal to 1:1 and reaction time was 24 hr. The effect of CMC concentration was also studied in order to obtain better hydrogel matrix properties. It was found that hydrogel prepared from 20 %wt CMC solution and crosslinked with citric acid  had proper swelling ratio and highest tensile strength. PTh/CMC composite hydrogels were then prepared, conductive PTh particles was added in CMC solution and hydrogels were casted and crosslinked in citric acid solution. The electro-responsive properties, bending response, of the PTh/CMC composite hydrogel under DC electric field was finally examined.