A novel nanocomposite from multiwalled carbon nanotubes functionalized with a conducting polymer

A nanocomposite of a multiwalled carbon nanotube and polythiophene was prepared by functionalizing the nanotube surface with a polythiophene, poly [3-(2-hydroxyethyl)-2,5-thienylene], containing pendant hydroxyl groups. The composite was characterized by IR, high resolution TEM and conductivity measurements. The poly [3-(2-hydroxyethyl)-2,5-thienylene] (PHET) was synthesized by the oxidation polymerization of 2-(3-thienylethanol) using FeCl3 and CHCl3. Multiwalled carbon nanotubes were synthesized by a microwave CVD method and oxidized with potassium permanganate using a phase transfer catalyst in mild conditions. The COOH groups formed on the nanotube surface were converted to COCl using thionyl chloride and it was then condensed with the polythiophene at high temperature in anhydrous DMF High resolution TEM images showed that the functionalization provided a firm coating of the conducting polymer on nanotube walls. This nanocomposite with PHET grafted to CNT showed higher conductivity than a nanocomposite of PHET and CNT in the same percentage weight composition prepared by ultrasonic mixing of the two. Such a material was designed and synthesized with a view to electronic and sensor applications.