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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]

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]

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]

In this work, the first example of fabricating feature sizes less than 10 nm by using block copolymer lithography on an organic-inorganic hybrid block copolymer material is described. A unique class of well-defined block copolymers which contain polyhedral oligomeric silsesquioxane (POSS) was used for this achievement. Two POSS containing block copolymers (BCPs) with high a degree of polymerization of POSS and a narrow polydispersity index (PDI) were synthesized by living anionic polymerization of styrene (PS-b-PMAPOSS) or methyl methacrylate and methacrylate functionalized POSS (PMMA-b-PMAPOSS). Both BCPs indicate well-defined lamellar or cylinder microphase-separated domains. The excellent self-assembly characteristics of these BCPs in thin-films combined with the outstanding high contrast in etching resistance and etch selectivity between PS or PMMA and PMAPOSS blocks leads to well-ordered line or hexagonally packed hole structures with a hole diameter of 9 rim. A one step oxygen plasma exposure converts the soft mask into a hard mask. The synthetic flexibility and the simplicity and ease of the self-assembly and etching process make these materials very attractive for creating small feature sizes. [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]

A dual-layer hollow fiber membrane with highly ordered isoporous surface and excellent mechanical strength was fabricated via block copolymer self-assembly and non-solvent induced phase separation. The isoporous outer layer formed by the self-assembly of poly(styrene- b -4-vinylpyridine) (PS4VP) was based on a poly(vinylidene fluoride) (PVDF) microfiltration membrane as the robust support layer. The prepared membranes showed high tensile strength between 6.21 and 6.95 MPa. The good adhesion between the layers was ascribed to the infiltration of PS4VP into the porous PVDF support, which in turn increased transport resistance as well. Therefore, intermediate-treatment agents were introduced to reduce the infiltration depth of PS4VP, and the resultant membranes showed improved water permeability and remained interfacial adhesion. The highest water flux of the membranes reached 90.8 L/m 2 h bar and the molecular weight cut-off was 74 kDa. Such a novel PS4VP/PVDF dual-layer hollow fiber ultrafiltration membrane is a promising candidate for highly selective separation. [ABSTRACT FROM AUTHOR]