Highly carbonized polyaniline micro- and nanotubes

We have obtained unique highly carbonized polyaniline micro- and nanotubes as a new, thermally stable nanomaterial for nanosensors and nanodevices with a wide range of possible applications, comparable to carbon nanotubes. Polyaniline nanostructures are easy to prepare and handle in wet conditions, including controlled growth. Temperature-induced transformations of polyaniline micro- and nanotubes into highly carbonized analogues have been observed at and above 800 °C, while the temperature was elevated slowly from 20 °C up to 1100 °C. Carbonized products have the same morphology (micro- and nanotubes), but a lower spin density than the starting material (e.g. 1014 g−1 for the sample heated at and above 800 °C, and 1019 g−1 before heating). Simultaneously, the electrical conductivity changes from 7.4 × 10−5 S/cm for the starting material to 4.8 × 10−9 S/cm, 1.3 × 10−11 S/cm and finally 2.4 × 10−6 S/cm for samples obtained at room temperature, 250 °C, 500 °C and 800 °C, respectively. Chemical transformations and unique molecular structures formed are discussed. Applications in nanotechnology, including sensors and electronic nanodevices, are expected in the light of experiments already performed.