| Autor: |
Jeon, Seungbae, Jun, Taesuk, Jo, Seongjun, Ahn, Hyungju, Lee, Seungwoo, Lee, Byeongdu, Ryu, Du Yeol |
| Předmět: |
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| Zdroj: |
Macromolecular Rapid Communications; Oct2019, Vol. 40 Issue 19, pN.PAG-N.PAG, 1p |
| Abstrakt: |
In the search for the formation of Frank–Kasper phases from diblock copolymer self‐assembly, a series of compositionally asymmetric poly(dimethylsiloxane)‐b‐poly(2,2,2‐triflouroethyl acrylate)s (PDMS‐b‐PTFEAs) are synthesized to produce PDMS‐rich phases with PDMS volume fractions (fPDMS) ranging from 0.746 to 0.869. As determined by small‐angle X‐ray scattering analysis, the Frank–Kasper σ and C14 phases are identified at fPDMS = 0.796 and 0.851, respectively, plausibly due to high conformational asymmetry (ε ≈ 2.20) between the two blocks. Intriguingly, the σ phase develops during heating from a short‐range liquid‐like packing (LLP) state, whereas the C14 phase is achieved at room temperature, which are both followed by a disordering at higher temperatures. Based on thermal experiments from a super cooled disordered state, the findings further provide compelling evidence of an LLP‐hexagonally packed cylinder‐σ transition and a direct pathway to the C14 phase during heating from an LLP state. [ABSTRACT FROM AUTHOR] |
| Databáze: |
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