| 초록 |
The sizes and structures of micelles formed in aqueous solutions of cationic OTAC and anionic ADS surfactants were investigated using small angle neutron scattering (SANS). For aqueous OTAC solutions, SANS data indicate that the structure of micelles is of sphere with core and hydrated shell up to OTAC 50 mM. As the total OTAC concentration increases, SANS data show that the micelles become larger and the transition in micellar shape from sphere to oblate ellipsoid takes place. For aqueous ADS solutions, SANS data point to the micelle structure of sphere with core and shell but this time up to ADS 100 mM. Above this concentration the spherical micelles changes to oblate ellipsoid with core and hydrated shell. The surfactant concentration at which micelle shape changes is termed as the shape transition concentration and such transitions may be explained qualitatively by the distortion of the hydrocarbon chains at high surfactant concentrations. |
