Water in soybean oil microemulsions as medium for electrochemical measurements

Journal of the Brazilian Chemical Society

Carla R. B. Mendonça¹  Clara I. D. Bica¹  Clarisse M. S. Piatnicki¹ 

[1] ,Universidade Federal do Rio Grande do Sul Instituto de Química Porto Alegre RS ,Brazil

关键词: microemulsions;    soybean oil;    voltammetry;    ferrocene;    oleic acid;   

DOI  :  10.1590/S0103-50532003000400021

来源: SciELO

【 摘 要 】

Microemulsions of water in soybean oil (w/o ME) were prepared with sodium dodecyl sulfate (SDS) as surfactant and amyl or isoamyl alcohol, as co-surfactants. Microemulsions containing 40.0% oil, 43.2% alcohol, 10.8% SDS and 6.0% water in weight, in the ratio 1:4 [SDS]:[alcohol] showed the highest thermodynamic stability. The aqueous droplet size and its diffusion coefficient Dw/o in the ME were determined through dynamic light scattering (DLS). Voltammetric measurements in the ME at a Pt disk ultramicroelectrode (ume) evidenced the oxidation of both water and ferrocene (Fc), and the reduction of oleic acid. The Dw/o values calculated from the limiting current being lower than the ones obtained from DLS indicate that water oxidation probably requires diffusion towards the electrode of both the droplets and the water molecules from inside the droplets. The results show that electroanalytical determinations can be carried out in w/o ME.

【 授权许可】

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