%0 journal article %@ 0021-9797 %A Jin, L.,Haramus, V.M.,Liu, F.,Xiao, J.,Eckerlebe, H.,Willumeit-Roemer, R. %D 2016 %J Journal of Colloid and Interface Science %N %P 201-209 %R doi:10.1016/j.jcis.2016.07.044 %T Interaction of a biosurfactant, Surfactin with a cationic Gemini surfactant in aqueous solution %U https://doi.org/10.1016/j.jcis.2016.07.044 %X The interaction between biosurfactant Surfactin and cationic Gemini surfactant ethanediyl-1,3-bis(dodecyldimethylammonium bromide) (abbreviated as 12-3-12) was investigated using turbidity, surface tension, dynamic light scattering (DLS) and small angle neutron scattering (SANS). Analysis of critical micelle concentration (CMC) values in Surfactin/12-3-12 mixture indicates that there is synergism in formation of mixed Surfactin/12-3-12 micelles. Although Surfactin and 12-3-12 are oppositely charged in phosphate buffer solution (PBS, pH7.4), there are no precipitates observed at the concentrations below the CMC of Surfactin/12-3-12 system. However, at the concentration above CMC value, the Surfactin/12-3-12 mixture is severely turbid with high 12-3-12 content. DLS and SANS measurements follow the size and shape changes of mixed Surfactin/12-3-12 aggregates from small spherical micelles via elongated aggregates to large bulk complexes with increasing fraction of Gemini surfactant.