Diffusion coefficients of ferrocene in composite materials containing ambient temperature ionic liquids

Diffusion coefficients (D) of ferrocene in composite materials composed of the ambient temperature ionic liquids 1,2-dimethyl, 3-(1-propyl) imidazolium tetrafluoroburate (DMPIBF4) or 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) and hexafluoropropylene-vinylidene fluoride copolymer were estimated using chronoamperometry. The values of D obtained with the composite materials based on DMPIBF4 ranged from 1 x 10(-13) to 2.5 x 10(-12) m(2) s(-1) and depended on the composition and pre treatment of the composite material. The latter value is equal to the diffusion coefficient of ferrocene in liquid DMPIBF4. The values obtained with the composite materials based on EMIBF4 ranged from 2 x 10(-13) to 9 x 10(-12) m(2) s(-1) and they are lower by a factor of more than four than that of ferrocene in liquid EMIBF4. (C) 2000 The Electrochemical Society. S0013-4651(99)07-077-9. All rights reserved.