We report the successful synthesis of previously inaccessible poly­(3-hydroxystyrene)-block-poly­(dimethylsiloxane) (P3HS-b-PDMS) block copolymers (BCPs) with varying volume fractions, molecular weights, and narrow dispersities by sequential living anionic polymerization. The chemical structure and molecular weight were fully characterized by 1H NMR and gel permeation chromatography. The BCP phase behavior was investigated using small-angle X-ray scattering (SAXS) and transmission electron microscopy. Temperature-resolved SAXS measurements from symmetric disordered sample were used to determine the interaction parameter (χ) using mean-field theory. The results provide an estimate for interaction parameter, χHS/DMS(T) = 33.491/T + 0.3126, with an upper bound value of 0.39 at 150 °C. The calculated χ for P3HS-b-PDMS is approximately 4 times higher than that observed in a commonly studied high-χ system, PS-b-PDMS. The ultrahigh interaction parameter observed here affords the formation of well-ordered materials at remarkably low molecular weight. The presence of both PDMS and P3HS provides significant versatility in terms of etch selectivity, while the hydroxystyrene domain offers additional functionality as it can be exploited for immobilizing functional organic moieties.

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Mesoporous polyimide composite films were fabricated by a soft template method using a microphase-separated structure of an amphiphilic block copolymer and porosification by ozonolysis. Poly(1,4-isoprene)-block-poly(2-vinylpyridine) was used as the template block copolymer. Poly(amic acid) (PAA), the precursor of polyimide, and resol, the cross-linker for stabilization of the nanostructure, were miscible into the poly(2-vinylpyridine) domain which is the hydrophilic domain of the template block copolymer. The mixture co-assembled and formed a periodic body-centered cubic nanostructure. The study of ozonolysis condition revealed that the reaction in hexane allowed porosification without the collapse of the nanostructure. Polyimide composite films with well-defined mesopores were successfully obtained by the sequential processes of the PAA composite film, namely, thermal annealing for crosslinking of resol, ozonolysis in hexane for the decomposition of polyisoprene domain, and thermal treatment for imidization of PAA. The domain spacing determined by smallangle X-ray scattering was 28.8 nm, and the average pore size based on scanning electron microscopy was 24 nm.

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.