The coarse-grained MARTINI model of Triton TX-100 has been validated by direct comparison of the experimental and calculated area increase in pure DPPC lipid bilayers and monolayers at water/air interfaces in the presence of surfactant and by comparison of electron density profiles calculated with more detailed atomistic models based on the CHARMM force field. Bilayer simulations have been performed and compared with monolayers and with atomistic models. The validated CG model has been employed to study the phase separation of TX-100 molecules in lipid bilayers and the effect of the lipid bilayer curvature.