The surfactants in the bulk are considered to be below the critical micelle concentra-tion (CMC), thus the bulk chemical potential of the surfactants µ b is that of an ideal solution with no contributions coming from the interactions between surfactants. Imposing thermodynamic equilibrium µ σ = µ b , the surface coverage Γ and the bulk molar fraction X are related in a transcendental equation that can be solved using the bisection or Newton method. For more details, see the original publication or the derivation from Sresht et al. The final result reads: