Abstract: The comparison of the micellar microstructures among three pure surfactant aqueous solutions with different molecular structures such as sodium alkylsulfates with normal, branched alkyl chains and with the polyethylene oxide chain inserted between the alkyl chain and the sulfatc polar head has been performed by using nuclear magnetic resonance spin-lattice relaxation time(t₁), spin-spin relaxation time(t₂) self-diffusion coefficient and two dimensional nuclear Overhause enhanced spectroscopy techniques. According to the ratios of t₂to t₁, the hydration layers of the micelles were deduced. The t₂/t₁values show that the hydrocarbon chains of surfactant Ⅱ are more compact in the micelles than that of surfactant I . NMR self-diffusion coefficients show that the micelles formed from surfactant Iare larger than those from surfactant Ⅱ . At last, the 2D NOESY technique was applied to confirm the arrangement of the polyethylene oxide chains outside the hydrophobic micelles.

Key words: Micellar microstructure, NMR relaxation, Self-diffusion coefficient, 2D NOESY