Abstract: A modified particle model was proposed and used to calculate the structural parameters of the W/O microemulsion of H2O/span-80+isopentyl alcohol/cyclohexane by dilution method.These parameters include radius of water nucleus(Rw),effective radius(Re),thickness of boundary layer(le),aggregation number of surfactant(n-s),and total number of particles(Ne).Free energy change(ΔG0c→i)resulting from the transfer of isopentyl alcohol from the continuous phase(C)to the boundary layer(i)has been determined.Calculation...