Characterization of nonionic surfactant micellar structures in organic solvents by small angle X-ray scattering (SAXS)

► Ethoxylated surfactants form colloidal aggregates in organic solvents. ► The aggregation is controlled by entropic and enthalpic factors. ► Entropy rules the formation of micelles via the hydrophobic effect. ► Enthalpy rules micelle formation by hydrogen bonding between polar additive and surfactant. ► SAXS can be used to follow all these influences.