Abstract

Copolymers prepared by electrodeposition from solutions containing both pyrrole and one of a variety of functionalised pyrroles were prepared. The composition of the copolymers was determined by XPS analysis involving deconvolution of the C(1s) spectrum using the C (1s) spectra for the homopolymers of pyrrole and the appropriate functionalised pyrrole. A constraint in the fitting routine was provided by quantification of the N (1s) signals. In general, addition of a small amount of pyrrole to a deposition solution containing only the functionalised pyrrole monomer resulted in a copolymer with a disproportionately large mole fraction of pyrrole units. For copolymers of pyrrole prepared with different functionalised monomers, the different variations of copolymer composition with deposition solution composition can be accounted for, in part, by the lower reactivity towards polymer deposition of the functionalised pyrrole. An additional influence on copolymer composition may come from different functionalised monomers giving rise to polymer matrices of differing porosity. Matrices with larger void spaces may allow preferential polymerisation of the smaller monomer species (pyrrole). Examples are given illustrating how optimisation of copolymer composition is of advantage in the preparation of modified electrode sensors for use in biosensing and olfactory systems. (C) 2001 Elsevier Science B.V. All rights reserved.