Electrosynthesis and characterization of new conducting copolymer films from 1-naphthol and methyl naphthyl ether

Abstract

New conducting polymer films have been prepared on platinum electrodes by anodic polymerization of 1‐naphthol in the presence of methyl naphthyl ether (MNE) in MeCN containing 0.1 M LiClO4. The presence of MNE was found to suppress oligomer formation and significantly affect the physicochemical properties of the polymeric films formed via copolymerization, as confirmed by IR and elemental analysis. In contrast to the autocatalytic polymerization mechanism observed during poly(1‐naphthol) formation, a competitive catalytic‐inhibiting mechanism was found for the copolymer. The copolymer (1:1 and 1:10 1‐naphthol:MNE) showed electrochemical activity similar to that of poly(1‐naphthol). The copolymer films resisted degradation in MeCN effectively and charging–discharging cycles led to doubling of the redox charge after about 20 cycles, while poly(1‐naphthol) films lost 90% of the redox charge under the same conditions. The conductivity of copolymer (1:1) films were 1–2 orders of magnitude lower than that of poly(1‐naphthol). The diffusion coefficients of the charge transfer for the doping–dedoping processes of the copolymer films were slightly lower than for poly(1‐naphthol), but the diffusion coefficients for the redox [Fe(CN)6]3−/4− were comparable for both films. © 2000 Society of Chemical Industry

Electrosynthesis and characterization of a new electro‐active polymer from 2‐phenylazo‐1‐naphthol

“…The complete absence of a reduction peak indicates that the oxidation products are involved in a subsequent chemical reaction. The behaviour is typical for deposition of insulating films from the oxidation products17 and opposite to the oxidation behaviour of 1‐naphthol, where the magnitude of the oxidation peak was found to increase with increasing the number of potential cycles 14. 16 In MeCN, and during potential cycling in the anodic direction, some soluble oxidation products were found to drop from the electrode surface, as reported before for 1‐naphthol 16.…”

“…The Nernstian slope of 60 mV indicates 1:1 electron:proton redox processes due to the quinone/quinol electrotransformations. Figure 6 shows that i p increases linearly with v 1/2 at v > 0.1 V s −1 , indicating a semi‐infinite linear diffusion regime12 while it increases linearly with v at v < 0.1 V s −1 , as usually reported for surface‐attached redox sites in redox and conducting polymers 17. 29, 30 The relationship of i p (A cm −2 ) versus v (V s 1 ) can be used to evaluate the surface concentration of the quinone sites in the polymer films, Γ (mol cm −2 ) according to the following equation:31, 32 where n is the number of electrons involved in the redox processes ( n = 2), F is the Faraday constant (96 500 C equiv −1 ), R is the gas constant (8.314 J K −1 mol −1 ) and T is the absolute temperature (K).…”

“…This Γ value is comparable to the value calculated from the peak charge (0.0 V–0.6 V); Γ = 3.3 × 10 −9 mol cm −2 . Chronocoulometry can be used to calculate the diffusion coefficient of the charge transport through the polymer films, D , according to the Cottrell equation:16, 17, 31 where q is the charge density (C cm −2 ), q dl is the charge density used to charge the double layer and c is the concentration of the redox sites in the polymer film (mol cm −3 ); c = Γ / χ , where χ (cm) is the film thickness. Equation 2 can be used when q / q total < 0.67,33 where q total is the total charge density needed for completion of the redox process.…”

“…The structure of poly (1‐naphthol) involves alternating fused naphthalene and furan rings. The first conducting copolymer derived from 1‐naphthol and methyl naphthyl ether was reported to have better degradation resistance than poly (1‐naphthol) but inferior conductivity 17. Although the strategy of polymerizing substituted monomers to improve the parent polymer properties was intensively employed for many conducting polymers, such as polyaniline,18–21 polypyrrole22–25 and polythiophene,26–28 electropolymerization of substituted 1‐naphthol seems to have received no attention yet.…”

Preparation of electrospun electroactive POMA fiber mats

“…1(a), curve A, shows the characteristic stretching peaks of POMA at wavenumbers of 1255 and 1025 cm −1 , which were assigned to COC stretching of the alkyl aryl ether linkage. In addition, the characteristic bands at wavenumbers of 1409 and 1366 cm −1 were assigned to the in‐plane CH bending of the methyl group 49–51. Furthermore, UV‐visible absorption spectra of the PANI family were obtained in an NMP solution, as shown in Fig.…”