Electrosynthesis and properties of conducting polymers derived from aminobenzoic acids and from aminobenzoic acids and aniline

Abstract

The electrochemical polymerisation of 2-, 3-, and 4-aminobenzoic acids and of mixtures of aniline and aminobenzoic acids in various ratios has been carried out by cyclic potential sweep in sulphuric acid solution. Polymers are formed in all cases and the rate of polymerisation is increased by the addition of aniline. The polymers formed have been characterised voltammetrically and evidence concerning the polymer structure and chemical composition has been obtained from IR spectroscopy and scanning electron microscopy. The results suggest that 2-amino-, 3-amino-and 4-aminobenzoic acid all form short-chain conducting polymers. Films from polymerisation of aniline and aminobenzoic acid mixtures show characteristics of both components and demonstrate the in¯uence of aminobenzoic acids and their oligomers on the electrochemical and morphological properties of polyaniline formed by electropolymerisation. # (C.M.A. Brett). 0379-6779/01/$ ± see front matter # 2001 Elsevier Science B.V. All rights reserved. PII: S 0 3 7 9 -6 7 7 9 ( 0 0 ) 0 0 3 6 4 -7

Conducting polymers from aminobenzoic acids and aminobenzenesulphonic acids: influence of pH on electrochemical behaviour

“…[48,52] between potential limits to be specified below, for 30 cycles at a scan rate of 50 mV s (1 , using an analogue potentiostat constructed in this laboratory. For polymerisation of the aminobenzoic and aminobenzenesulphonic acids alone, a 0.05 M solution was used in 0.5 or 1.0 M H 2 SO 4 .…”

“…The films formed from substituted anilines also lead to compact films [48,52]. An example of the morphology of films formed by polymerisation of substituted anilines in sulphuric acid solution is given for poly(2-ABA) in Fig.…”

“…The electropolymerisation of carboxylate-substituted anilines (2-, 3-and 4-aminobenzoic acids (2-, 3-and 4-ABA, respectively)) [48] and sulphonate-substituted anilines (2-and 4-amino-benzene sulphonic acids (2-and 4-ABS, respectively)) [52] in sulphuric acid solution has recently been investigated by us. Polymer films were formed on glassy carbon substrates using cyclic potential sweep synthesis, and were characterised in sulphuric acid solution by cyclic voltammetry (CV).…”

“…Polymerisation of mixtures of aniline and the substituted aniline in different ratios was also carried out [48,52]. It was shown that aniline polymerisation dominates although the morphology of the films formed is changed from that of polyaniline alone by the presence of the substituted monomer and there is evidence from CV, chromatic properties and IR spectroscopic characterisation of the existence of both components.…”

Polyaniline-polypyrrole coating for solid phase microextraction

“…The coating deposited from the electrolyte with bigger PSS quantity was more homogeneous and mechanically stable. There are no special requirements for PPY deposition media, but polymerisation of aniline should be carried out in strong acidic solution [24]. As a rule, sulphuric acid is used to produce PANI.…”