The ability of surfactants to reduce the interfacial tension between fluids renders them essential ingredients in a wide range of products and applications including, among others, health and personal care products. This project aims to create a coarse grain (CG) force field (FF), able to predict the properties of surfactants' aqueous solution for a range of concentrations following a bottom to top approach. Within this context, we are interested in successfully predicting the behaviour of these systems in the region of high concentrations and in particular in the region where the transition from the micellar (L1) phase to hexagonal liquid crystal (H1) phase occurs. To achieve our goal, we use Molecular Dynamic simulations and we develop methodologies that overpass the underlying problem of the poor phase space sampling.