The cyclotriphosphazene-substituted diazoacetate homopolymer (polyPNDA′) (PNDA′ = hexaphenoxysubstituted phosphazene-containing methylene) and a novel poly(substituted methylene) block copolymer, polyPNDA′block-poly(hexyloxycarbonylmethylene) (polyPNDA'-b-poly-HDA′), were synthesized, and the self-assembly behavior of these polymers was studied in detail. A hexagonally packed aggregated structure was observed in the self-assembled structure of polyPNDA′, whereas a lamellar structure was observed in the microphase-separated nanoassembly of polyPNDA′-b-polyHDA′. These results indicate that a hierarchical structure composed of highly regular polyPNDA′ nanoaggregates and the long-range microphase-separated polyPNDA′ and polyHDA′ domains had formed.

A series of novel polyhedral oligomelic silsesquioxane (POSS)-containing triblock copolymers that self-assemble into hexagonally-packed cylinders of the POSS domain in a polystyrene (PS) matrix was developed in this study.

Herein, a novel rod‐coil type polyhedral oligomeric silsesquioxane (POSS)‐containing diblock copolymer was designed to enable the self‐assembly of hexagonally packed cylinders of the POSS‐containing domain in a poly(n‐butyl methacrylate) (PnBMA) matrix. When POSS‐containing diblock copolymers were synthesized with polyisoprene or poly(methyl methacrylate), cylindrical structures could not be obtained as POSS‐containing polymers form stretched rigid rods. This makes the formation of cylindrical structures with the POSS‐containing domain entropically unfavorable. Therefore, to obtain the cylindrical structures, we constructed a novel diblock copolymer using PnBMA to increase the steric bulk and segment volume of the flexible coil. Steric crowding of the butyl groups reduces the entropic free stretching energy of the PnBMA chains, which in turn encourages the formation of a POSS‐containing hexagonally packed cylindrical structure within the PnBMA matrix as the system minimizes the total free energy of the thermodynamically stable nanostructure. Small angle X‐ray scattering and transmission electron microscopy analyses indicated that cylinders of the POSS domain had formed. Oxygen plasma etching was then used on the thin film to selectively remove the PnBMA domain to yield line and space structures with a high degree of long‐range order and a 14 nm feature size. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2234–2242

A new class of periodically nanostructured polythiophene materials with high regularity and numerous morphologies is prepared through the cooperative self-assembly of polythiophene derivatives with a templating block copolymer (BCP) and poly(1,4-isoprene)-blockpoly(methacrylic acid) (PMA). The selection of the hydrophilic and aprotic triethylene glycol (TEG) group as side chains on polythiophene and the use of hydrophilic and protic PMA are crucial to producing well-ordered nanostructures in polythiophene films, as it enables selective coassembly within the hydrophilic domain through hydrogen bonding. The composite films are shown to have formed hexagonally packed cylinders with 28 nm periodicities based on small-angle X-ray scattering and transmission electron microscopy. The formation of hydrogen bonding is revealed by a shift in the carbonyl peak of PMA in the Fourier transform infrared spectra of the composite film relative to the neat film. This suggests that the TEG-functionalized polythiophene selectively incorporates into PMA.Recently, various methods have been suggested for creating nanostructures of π-conjugated polymer materials in a wide range of domain sizes. 7-9 Particularly, polythiophene derivatives have been investigated as representative π-conjugated polymers because of their superior charge carrier mobility, stability, and processability. 10,11 Ever since several substituted thiophene monomers were found to undergo living chain-growth polymerization, there has been a growing interest in the self-assembly of block copolymers (BCPs) composed of widely used polythiophene derivatives. 12 Although the self-assembly of polythiophene-based BCPs can be used to develop well-ordered nanostructures with tailorable morphologies and domain sizes, the rigid polythiophene backbone forms a rod-like structure that renders the controllability of the polythiophene-based so-called "rod-rod" BCP nanostructure difficult. [13][14][15] Another method for producing well-ordered nanostructures of π-conjugated polymers is to use the self-assembly of so-called "rod-coil" BCPs composed of rigid rod polythiophene and flexible coil polymers such as polystyrene-block-poly(3-hexylthiophene) (P3HT), poly(1,4-isoprene)-block-P3HT (PI-b-P3HT), 16 P3HT-block-poly(2-vinylpyridine) (P3HT-b-P2VP), 17 and P3HTblock-polylactide. [18][19][20] The introduction of the flexible coil block is expected to bring synergistic improvements in the mechanical, optoelectronic, and self-assembly properties for a wide variety of polythiophene derivatives. However, these rod-coil BCPs were synthesized using multistep polymerization techniques, which require the end functionalization of segments and additional purification of Additional supporting information may be found in the online version of this article.