Small-angle X-ray scattering from micellar solutions of gemini surfactants

In an earlier work, we had studied small-angle neutron scattering (SANS) from micellar solutions of bis-cationic C16H33N+(CH3)2–(CH2)m–N+(CH3)2C16H33, 2Br− gemini surfactants, referred to as 16-m-16, 2Br−, for several spacer lengths. This Letter reports the results of small-angle X-ray scattering (SAXS) experiments on the above system for spacer lengths of m=3, 4 and 12. It is seen that SAXS distributions are qualitatively different from the SANS distributions. These experiments show that a combined SANS and SAXS study can be used for obtaining information on the counterion distribution around the micelles.