Electrical conductivity of microemulsions : a case of stirred percolation

M. Laguës

The electrical conductivity G of water in oil microemulsions may be described by percolation models [1] : below a critical water concentration Øc, G seems to diverge as (Øc - Ø)- S', while for Ø > Øc G increases as (Ø - Ø c)-T'. This physical situation may be called stirred percolation, referring to the Brownian motion of the medium. The exponents S' and T' are a priori different from the corresponding S and T in the classical situation of frozen percolation. A simple model of stirred percolation accounts fairly well for the measured value of S' = 1.2 ± 0.1 while the accepted value for S is 0.7. The exponent T' (1.4 to 1.6 in our experimental case) is less significant of the difference between stirred and frozen percolation : the values for S' should be about 1.8 and the value accepted for S should be about 1.6.

Mots clés: Brownian motion; electrical conductivity; emulsions; microemulsions; stirred percolation; water in oil microemulsions; percolation models; model

Domaines: Articles anciens

M. Laguës. Electrical conductivity of microemulsions : a case of stirred percolation. Journal de Physique Lettres, 1979, 40 (14), pp.331-333. ⟨10.1051/jphyslet:019790040014033100⟩. ⟨jpa-00231637⟩