Molar mass

Quantum mechanics

Phase (matter)

Chemical physics

Statistics

Materials science

Scattering

Polymer

Physics

Quasicrystal

Mathematics

Copolymer

Condensed matter physics

Geometry

Composite material

Tetrahedron

Crystallography

Chemistry

Symmetry (geometry)

Flexibility (engineering)

Asymmetry

Physical Review Letters

Small angle x-ray scattering experiments on three model low molar mass diblock copolymer systems containing minority polylactide and majority hydrocarbon blocks demonstrate that conformational asymmetry stabilizes the Frank-Kasper σ phase. Differences in block flexibility compete with space filling at constant density inducing the formation of polyhedral shaped particles that assemble into this low symmetry ordered state with local tetrahedral coordination. These results confirm predictions from self-consistent field theory that establish the origins of symmetry breaking in the ordering of block polymer melts subjected to compositional and conformational asymmetry.

Conformational Asymmetry and Quasicrystal Approximants in Linear Diblock Copolymers