End Groups of Functionalized Siloxane Oligomers Direct Block-Copolymeric or Liquid-Crystalline Self-Assembly Behavior.

ABSTRACT: Monodisperse oligodimethylsiloxanes end-functionalized with the hydrogen-bonding ureidopyrimidinone (UPy) motif undergo phase separation between their aromatic end groups and dimethylsiloxane midblocks to form ordered nanostructures with domain spacings of <5 nm. The self-assembly behavior of these well-defined oligomers resembles that of high degree of polymerization (N)-high block interaction parameter (χ) linear diblock copolymers despite their small size. Specifically, the phase morphology varies from lamellar to hexagonal to body-centered cubic with increasing asymmetry in molecular volume fraction. Mixing molecules with different molecular weights to give dispersity >1.13 results in disorder, showing importance of molecular monodispersity for ultrasmall ordered phase separation. In c

SUBMITTER: Zha RH 

PROVIDER: S-EPMC4858755 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature