Controlling the shear-induced structural transition of rodlike micelles using nonionic polymer

We demonstrate that nonionic polymer can be used to control the shear-induc ed transition observed in the cationic rodlike micellar system of cetyltrim ethylammonium p-toluene sulfonate (CTAT). Hydroxypropyl cellulose (HPC) sup presses this transition, while poly(ethylene oxide) (PEO) enhances the zero -shear viscosity, with little change to the critical rates of the transitio n. It is proposed that the availability of hydrophobic moieties of HPC allo ws for its influence on the onset of the transition. This is consistent wit h binding, rheological, and small-angle neutron scattering (SANS) studies. Furthermore, quiescent SANS shows that both polymers affect intermicellar i nteractions, solvent-micelle interactions, and/or micellar length. While th e onset of the shear-induced transition may be altered with polymer, polyme r composition does not affect micellar flexibility and/or interactions in t he aligned transitioned state.