Block-copolymer aggregates for turbulent drag reduction

Hydrophobically modified block-copolymer assembly.

Small amounts (≥ 100 wppm) of high molecular weight polymers reduce drag in turbulent pipe flows (up to 80%). Numerous models exist for polymeric drag reduction but none does fully explain all experimental observations. Turbulent shear acting on polymers causes mechanical degradation of the polymers reducing their molecular weight and thus the drag reducing capability. We synthesise water soluble block-copolymers with hydrophobic blocks to self-assemble into aggregates in water and tackle the following questions: Can we tailor the polymer architecture? What is the degradation behaviour of such polymers? Will these polymers recover after mechanical shear degradation? Can the association strength between the hydrophobic blocks be controlled? How does turbulent flow interact with these polymers? Will it be possible to control the morphology of polymer aggregates in solution? Adressing these questions enables us to investigate the importance of polymer networks in turbulent drag reduction.