Rhamnolipid–SLES aqueous mixtures: From the molecular self-aggregation to the functional and ecotoxicological properties

•Rhamnolipids co-micellize with sodium lauryl ether sulfate (SLES) in aqueous solution with a significant Gibbs energy gain.•Mixed micelles are formed in any ratio, even though the cmc trend indicates unfavorable rhamnolipids-SLES interactions.•The behavior of the mixture is rationalized in terms of the different molecular features of the two surfactants.•The bulk and interfacial properties of the mixed surfactant solution show a common molecular explanation.•The low ecotoxicity of rhamnolipids reduces the environmental impact of surfactant formulations.