PREPARATION OF CHIRAL CONDUCTING POLYMER COLLOIDS

A novel method for the electrochemical synthesis of chiral conducting polyaniline (PAn) colloids has been developed, via the potentiostatic (+0.9V vs Ag/AgCl) polymerisation of aniline in the presence of either (1R)-(-)-10-camphorsulfonic acid ((-)-HCSA) or (1S)-(+)-10-camphorsul fonic acid ((+)-HCSA). The electrosynthesis was performed under hydrod ynamic conditions in an electrochemical flow cell using polyethylene o xide as a stabiliser. The optical activity of the colloidal polyanilin e dispersion was established by circular dichroism (CD) spectroscopy. Visible region CD bands were observed at ca. 420 nm and were attribute d to the macroasymmetry of the polyaniline salt chains. Mirror image C D spectra were obtained for colloids grown in the presence of (+)- or (-)-HCSA, suggesting enantioselectivity during colloidal salt formatio n.