Studies of the Interaction of Poly(ethylene oxide) with Sodium Dodecyl Sulfate by Gel Filtration

Abstract

Abstract The interaction between poly(ethylene oxide) (PEO), with a molecular weight of 6000, and sodium dodecyl sulfate (SDS) was studied by the gel-filtration method. The elution curve of the PEO–SDS system showed a tail of the elution volume smaller than that of SDS micelles at a concentration larger than about 4 mmol dm−3. This suggests that the PEO–SDS (PS) complex is formed in the system. The dissolution-state diagram in the presence of PEO was then constructed in which the fractions of SDS single ions, SDS micelles, and the PS complex were shown against the SDS concentration. For a constant concentration of PEO, the molecular weight of the PS complex increased with the increase in the concentration of SDS up to the CMC of the PEO–SDS system, beyond which it became constant. The molecular weight of the PS complex was estimated to decrease from 21000 at 0.025 wt% PEO to 15000 at 0.2 wt% PEO.