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Electrochemical synthesis of polyaniline from aniline/cyclodextrin inclusion complex

The electrochemical synthesis of polyrotaxane molecule composed of cyclodextrin and polyaniline (PANICD) was attempted (Fig 1). Polyrotaxanes are expected to exhibit different chemical, electrical and optical properties compared to the base polymer. Two different cyclodextrins were used: b-cyclodextrin and sulfated b-cyclodextrin. Due to the low stability of cyclodextrin in acidic solutions, the electrochemical synthesis of polyaniline in the presence of different amounts of cyclodextrins was carried out by electrochemical oxidation of aniline from neutral solutions of NaClO4. The inclusion complex formation between aniline and cyclodextrin, was tested by cyclic voltammetry. Measurements were carried out using Pt working electrode and aniline c=10-3-10-2 mol dm-3 in 1 mol dm-3 NaClO4 as supporting electrolyte solution. Different concentrations of cyclodextrin were used in order to obtain aniline:cyclodextrin ratios from 1:0, 1:10, 1:30, 1:50. The obtained results show that it is possible to form inclusion complex of aniline and cyclodextrin what is essential in an attempt to obtain polyrotaxane structure. Electrochemical synthesis of polymer was carried out from 10-2 mol dm-3 aniline to 10-1 mol dm-3 or 5 x 10-1 mol dm-3 cyclodextrin. It was shown that the polymerisation is slowed down with the addition of cyclodextrin (Fig. 2). Electrochemical quartz crystal microbalance and SEM method were used in order to characterise the obtained polymer layers.

polyaniline; cyclodextrin; polyrotaxsane

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