| Abstract [eng] |
Main objective of this study were to synthesize the layers of the PANI and PPY polymers on ITO glass using 2.4 T magnetic field and to obtain and investigate their chiral structures using the cyclic voltamperometry (CV) and circular dichroism (CD) and UV/Vis spectroscopy methods. Spin selectivity of these polymers was calculated in percentage and the synthesized layer surfaces were investigated by scanning electron microscopy (SEM). These electrochemically synthesized layers of polyaniline, monolayer-based polyaniline, and polypyrrole on transparent conductive electrodes were affected with and without a strong 2.4 T magnetic field. These layers were examined by CV and CD and UV/Vis spectroscopy. In addition, the surface of the layers was visualized by SEM. Under the influence of the strong magnetic field, chiral structures were formed in the polyaniline layer, which were confirmed by the CD spectra. By changing the poles of the electromagnet and by measuring the electrochemical parameters, the spin selectivity of 14% was determined at a potential of 445 mV versus the Ag/AgCl reference electrode. The layers of polyaniline, covalently attached to the electrode surface, are also chiral, but the chirality is opposite than in the previous sample. Spin selectivity of 9% at 550 mV potential was measured by changing the electromagnet poles. After the experiments with the PPY layer, the magnetic field did not affect the polypyrrole layer. Moreover, these layers were not stable enough for the electrochemical studies. On the surface of the polyaniline layers synthesized using the magnetic field, nanofibers with diameter of 50 nm were observed, which are formed much less without the magnetic field. The covalently bonded polyaniline layer is characterized by the shorter aggregated nanofibers between which 10-20 nm nanopores are observed. The surface of the polypyrrole is coated with granules. We have shown that chiral structures can be formed under the influence of the magnetic field, and it opens new perspectives for the application of a magnetic field to the synthesis of chiral structures. |
