SANS study of salt induced micellization in PEO–PPO–PEO block copolymers

Small-angle neutron scattering (SANS) measurements have been carried out from the aqueous solutions of polyethylene oxide (PEO)–polypropylene oxide (PPO)–PEO block copolymers of pluronics F88 and P84 in presence of salt KCl. It is seen that the effect of addition of salt is similar to that of increasing temperature. The pluronics exist as unimers at low temperatures and their micellization takes place when the salt is added or the temperature is increased. The measurements for different salts of the lyotropic series on the above pluronic systems show that micellar structure is sensitive to the sizes of the hydrated ions of these salts.