Kinetics and Energetics of Solute Segregation in Granular Block Copolymer Microstructures

• DOI: 10.1021/acs.macromol.8b02044
• Publication Date: 2018-12-14T22:56:42Z
• Authors: Bongjoon Lee; Markus Bleuel; Adrian Zhao; David Ott; Ilhem F. Hakem; Michael R. Bockst...
• Keywords: Polystyrene; Dihedral angle

The segregation kinetics of deuterated polystyrene (d-PS) within the grain boundary regions a lamellar poly(styrene-b-isoprene) copolymer is analyzed using combination electron imaging and mapping as well ultrasmall small-angle neutron scattering. Solute limited to high-angle boundaries (that is, between grains having misorientations that exceed threshold value). accumulation d-PS found be uniform across boundaries, reaching an equilibrium local concentration solute about 52 vol %. This interpreted consequence enabling relaxation perturbed chain conformations in regions, thus reducing elastic strain energy stored boundaries. estimated continuum layer deformation model compared experimental (relative) tension determined by analysis dihedral angles at triple junctions. A McLean-type interface adsorption demonstrated quantitatively capture both extent regions. reveals rate sensitive mobility while limiting defects. results provide basis for interpretation structure coarsening processes block blend systems are often result more granular microstructures (featuring smaller sizes) pristine analogues inform development strategic decoration defects enable new functionalities copolymer-based materials.