Sardar Vallabhbhai National Institute of Technology Surat

Using tensiometry, dynamic light scattering, small-angle neutron scattering, and steady-state and time-resolved fluorescence at 30 °C, this study examined four Gemini surfactants (8-4-8, 10-4-10, 12-4-12, 10-8-10) at 100 mM with and without 100 mM NaBr or NaSal, and found that longer alkyl chains lower the CMC (about 55.4 mM to about 1.2 mM) and enlarge micelles with higher aggregation numbers (13 to 39), that increasing the spacer from 4 to 8 carbons shrinks micelles (D_h about 2.6 nm to about 1.1 nm), that NaBr swells micelles by electrostatic screening (D_h about 4.8 nm) while NaSal elongates them markedly (D_h about 15.

Using tensiometry, dynamic light scattering, small-angle neutron scattering, and steady-state and time-resolved fluorescence at 30 °C, this study examined four Gemini surfactants (8-4-8, 10-4-10, 12-4-12, 10-8-10) at 100 mM with and without 100 mM NaBr or NaSal, and found that longer alkyl chains lower the CMC (about 55.4 mM to about 1.2 mM) and enlarge micelles with higher aggregation numbers (13 to 39), that increasing the spacer from 4 to 8 carbons shrinks micelles (D_h about 2.6 nm to about 1.1 nm), that NaBr swells micelles by electrostatic screening (D_h about 4.8 nm) while NaSal elongates them markedly (D_h about 15.