Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions
Autor(a) principal: | |
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Data de Publicação: | 2008 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000400023 |
Resumo: | Water/oil microemulsions (w/o ME) constituted by water, soybean oil, SDS (sodium dodecyl sulfate) and several short-chain alcohols were characterized from the viewpoint of its physical-chemical and electroanalytical properties. Different co-surfactants and surfactant:co-surfactant ratios were used, and the ME with the most favourable composition was used to study the kinetics of redox processes. For this purpose, cyclic voltammetry measurements using a Pt disk working ultramicroelectrode, an Ag/AgCl reference electrode and a Pt auxiliary electrode, and ferrocene as a probe, were performed. It was verified that the thermodynamic stability of the MEs increases with the co-surfactant content. The molecular structure and water solubility of the co-surfactant affect the electrical conductivity and the hydrodynamic radio of the MEs. Owing to the low diffusion coefficients verified in the MEs, measurements in transient state using conventional sweeping rates could be performed. Ferrocene oxidation in the ME has been demonstrated to proceed in quasi-reversibility conditions. Thus, the possibility of carrying out studies of cyclic voltammetry in vegetable oils under the w/o ME form was demonstrated. |
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Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsionsw/o microemulsionsphysical chemical propertiesredox processcyclic voltammetryvegetable oilsWater/oil microemulsions (w/o ME) constituted by water, soybean oil, SDS (sodium dodecyl sulfate) and several short-chain alcohols were characterized from the viewpoint of its physical-chemical and electroanalytical properties. Different co-surfactants and surfactant:co-surfactant ratios were used, and the ME with the most favourable composition was used to study the kinetics of redox processes. For this purpose, cyclic voltammetry measurements using a Pt disk working ultramicroelectrode, an Ag/AgCl reference electrode and a Pt auxiliary electrode, and ferrocene as a probe, were performed. It was verified that the thermodynamic stability of the MEs increases with the co-surfactant content. The molecular structure and water solubility of the co-surfactant affect the electrical conductivity and the hydrodynamic radio of the MEs. Owing to the low diffusion coefficients verified in the MEs, measurements in transient state using conventional sweeping rates could be performed. Ferrocene oxidation in the ME has been demonstrated to proceed in quasi-reversibility conditions. Thus, the possibility of carrying out studies of cyclic voltammetry in vegetable oils under the w/o ME form was demonstrated.Sociedade Brasileira de Química2008-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000400023Journal of the Brazilian Chemical Society v.19 n.4 2008reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532008000400023info:eu-repo/semantics/openAccessMendonça,Carla R. B.Bica,Clara I. D.Simó-Alfonso,Ernesto F.Ramis-Ramos,GuillermoPiatnicki,Clarisse M. S.eng2008-06-11T00:00:00Zoai:scielo:S0103-50532008000400023Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2008-06-11T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions |
title |
Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions |
spellingShingle |
Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions Mendonça,Carla R. B. w/o microemulsions physical chemical properties redox process cyclic voltammetry vegetable oils |
title_short |
Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions |
title_full |
Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions |
title_fullStr |
Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions |
title_full_unstemmed |
Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions |
title_sort |
Physical chemical properties and kinetics of redox processes in water/soybean oil microemulsions |
author |
Mendonça,Carla R. B. |
author_facet |
Mendonça,Carla R. B. Bica,Clara I. D. Simó-Alfonso,Ernesto F. Ramis-Ramos,Guillermo Piatnicki,Clarisse M. S. |
author_role |
author |
author2 |
Bica,Clara I. D. Simó-Alfonso,Ernesto F. Ramis-Ramos,Guillermo Piatnicki,Clarisse M. S. |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Mendonça,Carla R. B. Bica,Clara I. D. Simó-Alfonso,Ernesto F. Ramis-Ramos,Guillermo Piatnicki,Clarisse M. S. |
dc.subject.por.fl_str_mv |
w/o microemulsions physical chemical properties redox process cyclic voltammetry vegetable oils |
topic |
w/o microemulsions physical chemical properties redox process cyclic voltammetry vegetable oils |
description |
Water/oil microemulsions (w/o ME) constituted by water, soybean oil, SDS (sodium dodecyl sulfate) and several short-chain alcohols were characterized from the viewpoint of its physical-chemical and electroanalytical properties. Different co-surfactants and surfactant:co-surfactant ratios were used, and the ME with the most favourable composition was used to study the kinetics of redox processes. For this purpose, cyclic voltammetry measurements using a Pt disk working ultramicroelectrode, an Ag/AgCl reference electrode and a Pt auxiliary electrode, and ferrocene as a probe, were performed. It was verified that the thermodynamic stability of the MEs increases with the co-surfactant content. The molecular structure and water solubility of the co-surfactant affect the electrical conductivity and the hydrodynamic radio of the MEs. Owing to the low diffusion coefficients verified in the MEs, measurements in transient state using conventional sweeping rates could be performed. Ferrocene oxidation in the ME has been demonstrated to proceed in quasi-reversibility conditions. Thus, the possibility of carrying out studies of cyclic voltammetry in vegetable oils under the w/o ME form was demonstrated. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000400023 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000400023 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50532008000400023 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.19 n.4 2008 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
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1750318168976392192 |