Solubilization of Phenol in Micelles of (Ethylene Oxide)₇₈(Propylene Oxide)₃₀(Ethylene Oxide)₇₈ Pluronic F68 Tri-Block Copolymer in Aqueous Suspensions

Abstract

The effect of phenol solubilization on the behavior of (ethylene oxide)₇₈-propylene oxide)₃₀-(propylene oxide)₇₈ (EO₇₈-PO₃₀-EO₇₈) tri-block copolymer, Pluronic F68 (F68), in aqueous suspensions was investigated by rheology. We have shown that for the ternary F68/water/phenol mixture, the rheological properties and the conformational changes of F68 depended strongly on the amounts of phenol. The 20% F68 suspensions begin with a Newtonian behavior for small amounts of phenol and lose this behavior to become a non-Newtonian liquid plastic with increasing phenol concentrations (50% phenol); then the suspension became Newtonian again for 75% and 100% phenol. The results are attributed to the addition of phenol resulting in a sphere-to-rod micellar transition.

Keywords:

• copolymer conformation
• phenol solubilization
• Pluronic F68
• rheology

Acknowledgments

We would like to thank the Deanship of Scientific Research at Majmaah University for supporting this work.