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The formation of ABC triblock terpolymers through solution casting is still challenging. In this study, core–shell double gyroid network structures are fabricated via solution casting using poly(2,2,2‐trifluoroethyl methacrylate) (PTFEMA) (F)‐b‐[poly(4‐vinylpyridine) (P4VP) (P)]‐b‐[polystyrene (PS) (S)] (FPS) triblock terpolymers in N,N‐dimethylformamide (DMF). Upon heat treatment, the polymer tends to form a sphere‐in‐lamellar structure at the F/S interface. Given the solubility properties of each component in DMF, it is anticipated that the effective volume fraction of F relative to P would increase in concentrated solutions and the effective volume fraction of S would decrease. The microphase‐separated structure derived from the DMF solution consistently results in the formation of a network structure composed of a core–shell double gyroid, with F as the matrix, P as the shell, and S as the core, and their periodic lengths gradually increase to 110.8, 131.8, and 162.7 nm as increase molecular weights of PS blocks to 13.8, 20.7, and 28.8 kg mol−1. Based on the solubility properties of the polymer components highlighted in this study, the solvent selection strategy is broadly applicable to ABC triblock terpolymers featuring various polymer components, offering a more efficient avenue for fabricating core–shell double gyroid structures. [ABSTRACT FROM AUTHOR]

Advancements in nanotechnology and materials science have led to an increased demand for specific material functions, preparation, and design of polymer particles with ordered internal and surface mesostructures. In this work, well‐shaped spheres of poly(2,2,2‐trifluoroethyl methacrylate)‐b‐poly(2‐vinylpyridine) with four different molecular weights are prepared by 3D confined self‐assembly. After thermal annealing, these spheres exhibit ordered internal and surface mesostructure. Analytical studies suggest that the internal mesoporous structure is formed by the microphase separation properties of the diblock copolymers, while the formation of ordered mesopores on the surface is caused by the decomposition of the PTFEMA domains under electron irradiation. Other microphase‐separated structures, such as cylindrical and lamellar ones, are observed using solution casting and non‐solution casting methods in the same diblock copolymer, indicating that the 3D confined environment induces the formation of internal ordered spherical microphase‐separated structures in the particles. [ABSTRACT FROM AUTHOR]

A facile approach to block copolymer (BCP) domain orientation control in thin films has been demonstrated by employing a BCP with liquid crystalline semifluorinated side chains by tuning the composition of the copolymers of the bottom surface layer (BSL). 1H,1H,2H,2H-Perfluorodecanethiol was attached to a precursor polymer, polystyrene-block-poly(glycidyl methacrylate) (PS-b-PGMA), to obtain a novel BCP with a C8F17-containing liquid crystal (LC) side chain (PS-b-P8FMA). Anisotropic hexagonally packed cylinder domains in a bulk state were first characterized by transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). The observed morphology transition of BCPs with different fluorinated side chain lengths of –CF3, –C4F9, and –C6F13 suggested the decisive effects of LC side chain ordering on the anisotropic nanostructures. In the thin film study, poly(methyl methacrylate-random-2,2,2-trifluoroethyl methacrylate-random-methacrylic acid) (PMMA-ran-PTFEMA-ran-PMAA) solution was used as BSLs for tuning the desired periodicities. The surface free energy (SFE) of BSL was simply tailored by changing the composition of comonomers. In atomic force microscopy (AFM) characterization, long-range ordered perpendicularly oriented BCP domains in a hexagonally packed array or parallel oriented BCP domains as striation patterns were easily fabricated on non-preferential or preferential BSL, respectively. The study presents a novel approach to tunable thin film periodicities without changing or modifying BCPs, which is desired in next-generation BCP lithography. [ABSTRACT FROM AUTHOR]

The optoelectronic properties of π‐conjugated polymers in the film state are known to be strongly affected by their structure. Inspired by this idea, the ordered‐structure‐induced electrochemical post‐functionalization (ePF) of poly(3‐(2‐ethylhexyl)thiophene) (P3EHT) films are reported. The structure of P3EHT films can be controlled by changing the solvent used to prepare them. The use of chloroform or chlorobenzene as the solvent results in amorphous P3EHT films, whereas P3EHT films with ordered structures are prepared when tetrahydrofuran is used as the solvent. The amorphous P3EHT films are not electrochemically functionalized. By contrast, ePF of the P3EHT films with an ordered structure is successful. In situ conductance measurements reveals that the successful ePF of the P3EHT films with an ordered structure originates from their greater electrochemical conductivity compared with that of amorphous P3EHT films. [ABSTRACT FROM AUTHOR]

A highly conformable long‐range ordered double gyroid structure with the space group Ia3d is obtained by the self‐assembly of a poly(2,2,2‐trifluoroethyl methacrylate)‐b‐poly(2‐vinyl pyridine) (PTFEMA‐b‐P2VP) diblock copolymer through solution casting. 9 different PTFEMA‐b‐P2VP samples are synthesized, each of which has a different mass fraction to others, with the product containing 47 wt% of PTFEMA exhibiting a double gyroid structure. Analysis of the transmission electron microscopy and scanning electron microscopy images of this product have revealed that the structural planes of the obtained 3D sample are in good agreement with the typical (211), (110), and (111) planes of the Ia3d space group, which is also supported by small angle X‐ray scattering spectroscopy, therefore confirming that the samples formed a long‐range double gyroid structure over a large area. [ABSTRACT FROM AUTHOR]

Preparation of functional domains with a spacing of 10 nm is a benchmark set to fabricate next‐generation electronic devices. Organic–inorganic block copolymers form well‐ordered microphase separations with very small domain sizes. The design and preparation of a novel block copolymer consisting of syndiotactic polymethyl methacrylate (st‐PMMA) and polyhedral oligomeric silsesquioxane (POSS)‐functionalized polymethacrylate, designated as st‐PMMA‐b‐PMAPOSS, which can recognize functional molecules, are reported. The st‐PMMA segments form a helical structure and encapsulate C60 in the helical nanocavity, leading to the formation of an inclusion complex. Although the ordering of the domains is not high, C60 domains that are in a quasi‐equilibrium state, with about 10‐nm domain spacings, are generated using st‐PMMA‐b‐PMAPOSS that can recognize functional molecules. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2181–2189 [ABSTRACT FROM AUTHOR]

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)‐block‐poly(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. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1105–1112 [ABSTRACT FROM AUTHOR]

The synthesis of an n-type π-conjugated hyperbranched polymer, hyperbranched polypyridine, is described. The polymer is obtained by copolymerization of 2,4,6-tribromopyridine and 2,5-dibromopyridine via chain-growth condensation polymerization catalyzed by Ni(dppp)Cl2. The NMR and fourier transform infrared results indicate the successful introduction of the branching unit into polypyridine by this cross coupling approach. The results of UV-vis spectroscopy and cyclic voltammetry suggest that the introduction of the branching unit contributes to a quick response during electrochemical doping due to the diffusion of dopant enhanced by the hyperbranched structure. [ABSTRACT FROM AUTHOR]

ABSTRACT 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) (P nBMA) 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 P nBMA 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 P nBMA chains, which in turn encourages the formation of a POSS-containing hexagonally packed cylindrical structure within the P nBMA 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 P nBMA 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 [ABSTRACT FROM AUTHOR]

ABSTRACT This study demonstrates the synthesis of mesoporous carbon materials utilizing the self-assembly of a block copolymer and its electrocatalytic activity for oxygen reduction. Fine and mesoporous carbon containing ferrum (Fe) and nitrogen (N) species has been successfully synthesized by multi-step pyrolysis of a self-assembled imide film fabricated via a soft template approach. The obtained sample has well-ordered mesostructure accompanied by uniform pores with diameter of 4.8 nm and BET surface area of 1660 m2 g−1. This material is tough enough to retain its mesostructured even after mechanical ball milling, which will be essential in the application as a fuel cell catalyst. Promising catalytic activity for electrochemical oxygen reduction owing to enhanced mass transport has been demonstrated. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 464-470 [ABSTRACT FROM AUTHOR]

ABSTRACT A series of poly(arylene ether ether nitrile)s with different chain lengths of the alkylsulfonates (SPAEEN- x: x refers number of the methylene units) are successfully synthesized for fuel cell applications. The polymers produced flexible and transparent membranes by solvent casting. The resulting membranes display a high thermal stability, oxidative stability, and higher proton conductivity than that of Nafion 117 at 80 °C and 95% relative humidity (RH). Furthermore, the SPAEEN-12 with the longest alkylsulfonated side chain exhibits a higher proton conductivity at 30% RH than that of SPAEEN-6 despite the lower IEC value, which indicates that the introduction of longer alkylsufonated side chains to the polymer main chain induces an efficient proton conduction by the formation of a well-developed phase-separated morphology. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 21-29 [ABSTRACT FROM AUTHOR]

A series of block copolystyrene derivatives, poly{[4-(4-sulfobutyloxy)styrene] x- block-[4-( n-butoxystyrene)] y} (PSBOS x- b-P nBOS y), containing a flexible alkylsufonated side chain and hydrophobic alkoxy chain with various ion exchange capacities (IECs) have been synthesized based on living anionic polymerization. The resulting crosslinked membranes were prepared using 4,4′-methylene-bis[2,6-bis(hydroxyethyl)phenol] as the crosslinker in the presence of methanesulfonic acid. The crosslinked PSBOS2.2- b-P nBOS1 membrane with IEC of 2.89 mequiv g−1 displays a high proton conductivity (0.01 S cm−1) at 30% relative humidity and 80 °C, which is comparable to that of Nafion. The well-developed phase separation and the continuous hydrophilic domains in the crosslinked PSBOS2.2- b-P nBOS1 membranes have been observed in a transmission electron microscope image. Moreover, the dynamic mechanical analysis measurement and Fenton's reagent testing show that the crosslinked PSBOS x- b-P nBOS y membranes have good mechanical properties and oxidative stability. These results indicate that the introduction of flexible alkylsulfonated side chains to the polystyrene main chains positively affect both the proton conductivity and oxidative stability. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 [ABSTRACT FROM AUTHOR]

Arrays of iron oxides as precursors of iron clusters were prepared by oxygen plasma treatment of block copolymer microphaseseparated nanostructures in thin films. Block copolymers composed of ferrocene-containing and silsesquioxane-containing polymethacrylate (PMAPOSS-b-PMAHFC) were successfully prepared, with different molecular weights and compositions and narrow molecular weight distributions, by living anionic polymerization. The formed microphase-separated nanostructures in the bulk were characterized by wide- and small-angle X-ray scattering (WAXS and SAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thin films were prepared from a solution of PMAPOSS-b-PMAHFC in tetrahydrofuran by spin coating onto silicon wafers. Fingerprint-type line nanostructures were formed in the PMAPOSS-b-PMAHFCs thin films after solvent annealing with carbon disulfide. Oxygen plasma treatment provided the final line arrays of iron oxides based on the formed nanostructural patterns. [ABSTRACT FROM AUTHOR]

Thermotropic POSS-containing poly(methacrylate) with long alkyl chain tethered polyhedral oligomeric silsesquioxane (POSS) in the side chain and the block copolymers (PMMA- b-PMAC11POSS) were developed by through living anionic polymerization. The resulting polymers indicated a phase transition temperature at 112 °C from spherocrystal to isotropic phase. The POSS-containing polymer segments tended to form matrix of microphase-separated nanostructures in the bulk even in the very low volume fraction, for instance, PMMA cylindrical nanostructure was obtained by PMMA175- b-PMAC11POSS11 (ϕPMAC11POSS = 0.44). The control of thin film morphology was carried out by not only solvent annealing, but also thermal annealing, resulting in the formation of well-ordered dot- and fingerprint-type nanostructures. This is the first report in a series of POSS-containing block polymers that are capable for thermal annealing to generate well-ordered microphase-separated nanostructures in thin films. The novel thermotropic POSS-containing block copolymer offers a promising material for block copolymer lithography. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 [ABSTRACT FROM AUTHOR]

The evolution of well‐ordered, sub‐10 nm, perpendicular lamellae from a disordered state is documented directly using in situ atomic force microscopy, cross‐sectional scanning electron microscopy, and grazing‐incidence small angle X‐ray scattering. Since block copolymer (BCP) self‐assembly occurs on extremely fast time scales, directly imaging the growth of perpendicular lamellae remains challenging. The lack of understanding behind early‐stage self‐assembly and how metastable defects can affect the kinetic behavior near thermodynamic equilibrium prevents the realization of defect‐free thin films. By characterizing the evolution of nanostructures using a high‐χ, perpendicular lamella‐forming BCP, poly(polyhedral oligomeric silsesquioxane)‐block‐poly(2,2,2‐trifluoroethyl methacrylate), over a wide temperature range, three stages in the evolution of perpendicular lamellae, characterized mainly by the root‐mean‐squared (rms) roughness, is observed. At temperatures lower than the glass transition temperatures (Tg), the film retains a smooth, disordered surface (rms roughness = 0.352 ± 0.006 nm), characteristic of spin‐coated films. Near the Tg, spinodal decomposition and the appearance of lamellae are detected as the rms roughness increases at 70 °C, before peaking at 82 °C at 0.83 nm, and decaying rapidly with increasing temperatures. Above the Tg, the rms roughness returns to 0.35 ± 0.03 nm, as defects are observed to annihilate sequentially. [ABSTRACT FROM AUTHOR]