Self – Assembly in System of Leciyhin and Nonionic Am phiphile f rom NMR Studies

The bin ary solution can solubilize variable quantities of lecithin depending on sample composit ion, the maximum amount being ۱ ۰ wt % of lecithin. The self-diffusion coefficients of Triton X-۱۰۰, D(T), water, D(W), and lecithin, D( L) were measured with the Fourier transform ed pulsed- gradient spin -echo (FT- PGSE) NM R technique. In the bina ry system, t he D(W) v alues decrea se continuo usly with increasing surfactant c oncentration (۰-۸۰ wt % surfactan t), whereas there is a s harp decreas e of the D( T) value until a minimum is reached, after wh ich there is a slow incr ease in the diffusion coefficient of Triton X-۱ ۰۰. The water diffusion data are analyzed with the cell diffusion model, and a constant hydrati on number, n = ۶ (molecules of water per EO group), to be consistent with a water continous structure u p to at least ۸۰ wt % T riton X-۱۰۰ at ۳۰۵ K. T he surfacta nt diffusion data are used to show t he formation of nonspherical normal micelles even in the very dilute region, and the micelles undergo size and/or shape changes with increased Triton X-۱۰۰. The micellar growth is more pronoun ced if the system contains lecithin. The D(T) a nd D(L) val ues are used to obtain t he Triton X-۱۰۰ mono mer concent ration, which is approximately equal to the cmc of Triton X-۱۰۰ in water.

کلیدواژه ها:

Triton X -۱۰۰ ، (FT-PGSE) NM R ، lecithin