Thermal and dielectric investigations on the blends of κ-carrageenan and nano-structured polyaniline

There are some biosensors and biochips for the recognition and quantization for particular biological molecules. They are made of conductive polymers and natural biomolecules such as protein, DNA and polysaccharides. The conductive polymers work as electric wires for signal transmission, while the natural biomolecules are receptors. Such electric devices are of complex and heterogeneous structures, in either single chain or condensed chains or dispersive phase separations. In order to investigate the complex structures of the polymer blends in the devices and the relation between the structure and the electrical properties, we have prepared several kinds of nano-structured polyaniline (PANI) with defined aggregate morphologies, i.e., nano-granules or nano-fibers with different aspect ratios. The blends of κ-carrageenan and PANIs have been prepared through sol–gel process. The multi-level structures of PANIs have been characterized with X-ray diffraction (XRD) and scanning electron microscope (SEM). The thermal analysis and dielectric relaxation spectroscopy help to evaluate and to understand the chain relaxation and the interfacial structures of the blends.