The surface properties in the mixed system of simply structured bolaform amphiphile sodium eicosanedioate (C_(20)Na_2) and cationic surfactant dodecyl triethylammonium bromide (C_(12)Et_3) were studied. Compared with the C_(12)Et3 single system, it was found that cmc and γ _(cmc) in the mixed system did not decrease significantly. Negative stained and FF-TEM, dynamic laser light scattering (DLS) and viscosity methods were used to investigate the aggregation behaviors in the mixed system. Global vesicles and tube-like aggregates were formed in the mixed solution and the mechanism of aggregation was proposed.

Key words: SURFACTANTS, AGGREGALES, QUATERNARY AMMONIUM COMPOUNDS, LIGHT SCATTERING, VISCOSITY