Abstract
A dodecagonal quasicrystalline (QC) morphology is identified in a poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) (SISO) tetrablock terpolymer based on evidence provided by transmission electron microscopy (TEM), small-angle X-ray scattering, and dynamic mechanical spectroscopy measurements. The QC state occurs at temperatures between those associated with simple hexagonal order (HEX) and the σ-phase (P4 2/mnm), T HEX < T QC < T σ < T ODT, where T ODT is the order-disorder transition temperature. All three morphologies are formed from spherical domains containing an O core surrounded by a shell of S that screens unfavorable segment-segment interactions with an I-rich matrix. TEM analysis reveals a QC morphology with 12-fold rotational symmetry but devoid of long-range translational order, along with locally coordinated structures consistent with dodecagonal quasicrystalline approximants. The SISO molecular architecture decouples control over the domain shape and interdomain interactions, leading to a multiplicity of packing symmetries.
Original language | English (US) |
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Pages (from-to) | 7636-7639 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 134 |
Issue number | 18 |
DOIs | |
State | Published - May 9 2012 |