Structure and aggregation proclivity of C12E3 in aqueous solution

► Dodecyl(triethylene glycol) and its dimers are modeled by DFT and ONIOM in water. ► Single molecules and dimers are very flexible and allow various stable geometries. ► The aggregation of monomers into dimer structures is a favorable process. ► Compact structures with shielding of head and tail fragments are more stable. ► Dimers prone to further aggregation are most populated.