Effect of aniline monomer concentration on PANI electropolymerization process and its influence for applications in chemical sensors

Autor(es)

Pedroza Dias Mello, Hugo Jose Nogueira ^[1] ; Mulato, Marcelo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Philosophy Sci & Letters Ribeirao Preto, Dept Phys, Av Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Synthetic Metals; v. 239, p. 66-70, MAY 2018.
• Citações Web of Science: 1

Resumo

Galvanostatic electrodeposited polyaniline thin films were studied and analysed, focusing on the influence of aniline concentration in the polymerization process and hence the answer of Extended-Gate Field-Effect-Transistor pH chemical sensor. A competition between the deposition efficiency and deposition rate was observed in the polymerization process according to aniline monomer concentration. This competition influences the structure-property relationship of polyaniline thin films. The polymerization occurred over fluorine doped tin oxide substrates and the polymerization solution contained aniline monomer in four concentrations from 0.10 to 0.25 M. The current density was 1.0 mA/cm(2), the deposition time was 300 s, resulting in a deposited charge of 300 mC/cm(2). The thickness of the PANI thin films presented a dual behaviour, increasing up to 121 +/- 5 nm for 0.20 M (sample PANI20), and then, decreasing down to 68 +/- 3 rim for 0.25 M (sample PANI25). The optical properties presented an inverse behaviour compared to the thickness, as expected, with small brightness and optical reflectance for sample PANI20, once that it is the thicker sample and absorbs more light. PANI20 presented the optimized relation between deposition rate and deposition efficiency. The sensitivity depends on chemically-sensitive film's surface quality, which is determined by the deposition efficiency. (AU)

• Processo FAPESP: 14/09562-4 - Biossensores microeletrônicos associados a técnicas eletroquímicas
• Beneficiário: Marcelo Mulato
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/24559-0 - Matriz multimodal de biossensores enzimáticos: Potenciométrico diferencial, óptico e condutométrico.
• Beneficiário: Hugo José Nogueira Pedroza Dias Mello
• Modalidade de apoio: Bolsas no Brasil - Doutorado