Interfaces and Their Impact on Polymer Dynamics

March 15, 2023
Interfaces and Their Impact on Polymer Dynamics
By selectively hydrogenating a short segment (blue spheres) within a deuterium-labeled flexible polymer (cyan spheres) that is bound to a rigid polymer (yellow spheres) as a block copolymer, the impact of the interface formed by the rigid polymer on the dynamics of the flexible polymer was revealed.

Scientific Achievement

Monomers near the interface between flexible and rigid portions of a block copolymer have slower dynamics than those away from the interface. The origin of this complex behavior was explained by combining neutron scattering and coarse-grained molecular dynamics simulations.

Significance and Impact

Block copolymer structure and dynamics impacts their function, such as in batteries and in drug delivery applications. The study reveals that the presence of an interface no longer impacts polymer dynamics after reaching five segments from the interface.

Research Details

  • Isotopically-labeled block copolymers were synthesized at the Center for Nanophase Materials Sciences (CNMS).
  • Neutron spin echo spectroscopy and small-angle neutron scattering experiments were performed at the SNS.
  • The CNMS performed the coarse-grained simulations.

“Understanding interfacial block copolymer structure and dynamics,”
Goswami, M., Iyiola, O. O., Lu, W., Hong, K., Zolnierczuk, P., Stingaciu, L.-R., Heller, W. T., Taleb, O., Sumpter, B. G. and Hallinan Jr., D. T.
Macromolecules 56, 762-771 (2023). DOI: https://doi.org/10.1021/acs.macromol.2c01814