A proton nuclear magnetic resonance relaxation study of C12E6/D2O

Aqueous solutions of the nonionic surfactant, n-dodecylhexaoxyethylene glyc ol [C12H25(OCH2CH2)(6)OH], termed C12E6, form various phases at room temper ature: there is a micellar phase at high water content, hexagonal, cubic, a nd lamellar mesophases at intermediate water contents, and an isotropic pha se at very low water content. Proton nuclear magnetic resonance (NMR) T-1(- 1) relaxation rates have been measured for the C12E6/D2O system as a functi on of composition, spectral frequency, and temperature. The results are int erpreted in terms of the possible molecular motions for the C12E6 molecule in the different phases. A review of relaxation theory is presented with sp ecial attention to molecular exchange between sites that are associated wit h different relaxation rates.