Proton conduction mechanisms in GPTMS/TEOS-derived organic/silica hybrid films prepared by sol-gel process

Autor(es)

Monteiro, Daniela A. ^[1] ; Gozzi, Giovani ^[1] ; Chinaglia, Dante Luis ^[1] ; Oliveira, Jr., Osvaldo N. ^[2] ; de Vicente, Fabio S. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Dept Phys, Inst Geosci & Exact Sci, BR-13506900 Rio Claro, SP - Brazil

^[2] Univ Sao Paulo, Sao Carlos Inst Phys, CP 369, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Synthetic Metals; v. 267, SEP 2020.
• Citações Web of Science: 0

Resumo

In this work, we employed impedance spectroscopy measurements to investigate the electrical properties of hybrid films obtained with the sol-gel process using 3-glycidoxypropyltrimethoxysilane (GPTMS) and tetra-ethylorthosilicate (TEOS) at different GPTMS/TEOS molar ratios and temperatures of thermal treatment. For the GPTMS/TEOS-derived samples with 1:1 composition, the DC conductivity (adc) and charge carrier mobility (mu dc) increased linearly with heat treatment temperature from 25 to 80 degrees C, while adc increased from 3.2 to 22.4 nS/cm with a 7-fold increase in the GPTMS concentration. These results could be rationalized with the Miller-Abraham model using a charge carrier activation energy of 0.54 +/- 0.03 eV. Using FTIR spectroscopy we demonstrated that the structural arrangement of the hybrid matrix involves epoxy ring opening, thus favoring proton con-duction, which occurs as in the Grotthuss mechanism via hopping between nearest oxygen atoms of polymerized glycidoxypropyl groups. It is significant that electrical properties of organic/silica matrices can be predicted and tuned for tailored applications using the modeling presented here. (AU)

• Processo FAPESP: 11/18149-5 - Estudo de filmes híbridos de sílica luminescentes e fotossensíveis preparados via sol-gel
• Beneficiário: Fábio Simões de Vicente
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/14262-7 - Filmes nanoestruturados de materiais de interesse biológico
• Beneficiário: Osvaldo Novais de Oliveira Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático