Pressure-Induced Reactivity in the Emeraldine Salt and Base Forms of Polyaniline Probed by FTIR and Raman

Autor(es)

Nobrega, Marcelo M. ^{[1, 2]} ; Ceppatelli, Matteo ^{[2, 3]} ; Temperini, Marcia L. A. ^[1] ; Bini, Roberto ^{[2, 4]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, BR-05513970 Sao Paulo - Brazil

^[2] European Lab Nonlinear Spect, LENS, I-50019 Sesto Fiorentino, FI - Italy

^[3] Natl Res Council Italy, Inst Chem OrganoMetall Cpds, ICCOM CNR, I-50019 Florence - Italy

^[4] Univ Florence, Dipartimento Chim Ugo Schiff, I-50019 Sesto Fiorentino, FI - Italy

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 118, n. 47, p. 27559-27566, NOV 27 2014.
• Citações Web of Science: 12

Resumo

This report presents the influence of the morphology on the pressure-induced reactivity of the doped (PANI-ES) and dedoped (PANI-EB) forms of polyaniline using Raman and FTIR techniques. Our PANI-EB FTIR spectroscopy data showed an intensity exchange among characteristic bands of the quinoid and benzoic segments above 9 GPa, suggesting a specific coupling reaction between adjacent quinoid rings. The reaction kinetic was followed, and the results showed a dependence of the rate constant with pressure, as well as the activation volume, presented an inversion from negative to positive at 13 GPa, suggesting that steric factors have a role in the reactivity of the species. Raman spectra of PANI-ES showed a broadening and a blue shift of the bands as the pressure increases preceding the almost complete amorphization of the polymer; after decompression, some minor spectral changes were observed, suggesting the occurrence of the dedoping and cross-linking reactions in less extension than PANI-EB. (AU)

• Processo FAPESP: 10/18107-8 - Estudo das estruturas de nanofibras de PANI e de seus híbridos com nanoestruturas metálicas por espectroscopia Raman
• Beneficiário: Marcelo Medre Nobrega
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/05983-2 - Estudo do comportamento estrutural das formas sal e base de esmeraldina da polianilina com morfologia bulk e fibras frente à aplicação de alta pressão
• Beneficiário: Marcelo Medre Nobrega
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado