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Abstract
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Three distinct types of poly(3-hexylthiophene)
(P3HT)-based crystals were developed using unseeded and
seeded protocols. First, unseededflatfibrillar and scrolled halfring-like crystals were prepared by isothermal crystallization of
homo-P3HT and P3HT-b-poly(ethylene glycol) (PEG) block
copolymers. Anisotropic accumulation of grafted coily PEG
blocks on the opposite surfaces of P3HT half-rings having
extended backbones reflected scrolling, and their subsequent
crystallization also further intensified this scrolling. The PEGs
assembled into lamellae on both sides of P3HT half-rings with
dissimilar crystalline features, i.e., the outer PEG lamella was
thicker (17.4 nm) and wider (23.1 nm) compared to the inner one (15.0 and 18.1 nm). Furthermore, the crystallinity of PEG
coily blocks accumulated on the P3HT crystals did not change the extended state of P3HT backbones (17.5 nm) and also the
thickness of half-rings (11.0 nm). Second, with seeding homogeneous P3HT
7000
-b-PEG
5000 solution using homo-PEG
5000 tiny
crystals, the cubic PEG single crystals were sandwiched between grafted regioregular P3HT chains (>99%). The appearance of
(020)P3HT
and (100)P3HT
spots for tethered P3HTs beside (120)PEG prisms demonstratedflat-on orderly tethered P3HT
backbones on the PEG single crystalline substrate. Via conjunction between block copolymer and homopolymer single crystals in
channel (PEG)/wire (P3HT-covered PEG)/channel (PEG) epitaxials, the P3HT rigid brushes were found to be extended (17.35
nm) on lamellar PEG substrate (6.15 nm). Third, when homogenized P3HT7000
-b-PEG
5000
solutions were seeded by homoP3HT7000tiny crystals, the edge-on orientated fibrillar P3HT single crystals were acquired. Although the thickness (20−22 nm)
and length (60−63μm) of P3HT7000
-b-PEG
5000fibrillar single crystals resembled those of homo-P3HT7000ones, their backbone
lamination in the caxis were significantly different (2 versus 21); because the P3HT backbones were not capable of laminating
fr
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