Electrosynthesis of polyurethane-based core-shell PAn center dot (+)-HCSA colloids

The formation of core-shell colloidal particles based on polyurethane with a polyaniline coating has been investigated using an electrohydrodynamic pr ocessing method. It has been found that stable dispersions of highly optica lly active colloids can be formed both in the presence and absence of polys tyrene sulfonate when one hand of camphorsulfonate is used. In both cases, the optical activity increased upon standing after polymerisation. This was accompanied by transformation from the "tight coil" to "expanded coil" con formation as reflected in changes in the UV-visible spectra upon standing. In all cases, particle size increased with polymerisation time. This was in itially due to coating of single particles at shorter times and agglomerati on of these into much larger particles at longer times. (C) 2000 Elsevier S cience S.A. All rights reserved.