posted on 2017-03-09, 00:00authored byAndrew
J. Erwin, Weinan Xu, Hongkun He, Krzysztof Matyjaszewski, Vladimir V. Tsukruk
The surface morphology
and organization of poly(ionic liquid)s
(PILs), poly[1-(4-vinylbenzyl)-3-butylimidazolium bis(trifluoromethylsulfonyl)imide]
are explored in conjunction with their molecular architecture, adsorption
conditions, and postassembly treatments. The formation of stable PIL
Langmuir and Langmuir–Blodgett (LB) monolayers at the air–water
and air–solid interfaces is demonstrated. The hydrophobic bis(trifluoromethylsulfonyl)imide
(Tf2N–) is shown to be a critical agent
governing the assembly morphology, as observed in the reversible condensation
of LB monolayers into dense nanodroplets. The PIL is then incorporated
as an unconventional polyelectrolyte component in the layer-by-layer
(LbL) films of hydrophobic character. We demonstrate that the interplay
of capillary forces, macromolecular mobility, and structural relaxation
of the polymer chains influence the dewetting mechanisms in the PIL
multilayers, thereby enabling access to a diverse set of highly textured,
porous, and interconnected network morphologies for PIL LbL films
that would otherwise be absent in conventional LbL films. Their compartmentalized
internal structure is relevant to molecular separation membranes,
ultrathin hydrophobic coatings, targeted cargo delivery, and highly
conductive films.