End groups of functionalized siloxane oligomers direct block-copolymeric or liquid-crystalline self-assembly behavior

Vertaalde titel van de bijdrage: Eind groupen van gefunctionaliseerde siloxaan oligomeren controleren block-copolymeren of liquid crystal zelfassemblage gedrag

R.H. Zha, B.F.M. de Waal, M. Lutz, A.J.P. Teunissen, E.W. Meijer

Onderzoeksoutput: Bijdrage aan tijdschriftTijdschriftartikelAcademicpeer review

64 Citaten (Scopus)
268 Downloads (Pure)

Samenvatting

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 contrast, oligodimethylsiloxanes end-functionalized with an O-benzylated UPy derivative self-assemble into lamellar nanostructures regardless of volume fraction because of the strong preference of the end groups to aggregate in a planar geometry. Thus, these molecules display more classically liquid-crystalline self-assembly behavior where the lamellar bilayer thickness is determined by the siloxane midblock. Here the lamellar nanostructure is tolerant to molecular polydispersity. We show the importance of end groups in high χ–low N block molecules, where block-copolymer-like self-assembly in our UPy-functionalized oligodimethylsiloxanes relies upon the dominance of phase separation effects over directional end group aggregation.
Vertaalde titel van de bijdrageEind groupen van gefunctionaliseerde siloxaan oligomeren controleren block-copolymeren of liquid crystal zelfassemblage gedrag
Originele taal-2Engels
Pagina's (van-tot)5693–5698
Aantal pagina's6
TijdschriftJournal of the American Chemical Society
Volume138
Nummer van het tijdschrift17
DOI's
StatusGepubliceerd - 7 apr 2016

Vingerafdruk

Duik in de onderzoeksthema's van 'Eind groupen van gefunctionaliseerde siloxaan oligomeren controleren block-copolymeren of liquid crystal zelfassemblage gedrag'. Samen vormen ze een unieke vingerafdruk.

Citeer dit