June Huh

We investigate the influence of hard nanoparticles on the phase behavior of diblock copolymers. Using Monte Carlo simulations, we obtain phase diagrams as a function of the nanoparticle size and concentration. When the size of the nanoparticles becomes comparable to the radius of gyration of the minority (A) block, we observe the formation of new superstructures, where the particles self-assemble inside the copolymer micelles. We develop a theoretical model, based on the strong segregation limit

Self-assembled structures of brush block copolymers (BrBCPs) with polylactide (PLA) and polystyrene (PS) side chains were studied. The polynorbornene-backbone-based BrBCPs containing approximately equal volume fractions of each block self-assembled into highly ordered lamellae with domain spacing ranging from 20 to 240 nm by varying molecular weight of the backbone in the bulk state, as revealed by small-angle X-ray scattering (SAXS). The domain size increased approximately linearly with backbon

Block-copolymer-like supramolecules (see Figure) permit thermal tuning of the microphase period due to reversible supramolecular assembly and disassembly. The supramolecular system based on a binary end-functionalized blend forming diblock- and triblock-like supramolecules shows that the lamellar microphase upon heating swells up to almost 300%. Such effective temperature tunability of the microphase period may find a variety of uses in applications that require patterning over large dimensions.

The effect of cadmium chloride (CdCl 2 ) on the phase behavior of polystyrene- block -poly(4-vinylpyridine) copolymer (S4VP) was investigated by using rheometry, small-angle X-ray scattering, and transmission electron microscopy. For this purpose, symmetric S4VPs with various molecular weights were prepared by anionic polymerization. We found that with the addition of CdCl 2 the order-to-disorder transition of S4VP was significantly increased because of the intermolecular coordination connecting

We demonstrate that a minimal topographic pattern with a confinement depth (D) much less than the domain spacing of block copolymers (L0) can be used to achieve highly ordered hexagonal arrays or unidirectionally aligned line patterns over large areas. Cylinder-forming poly(styrene-b-ethylene oxide) (PS-b-PEO) thin films were prepared on a series of minimal single trench patterns with different widths (W) and D. Upon thermal annealing, hexagonal arrays of cylindrical microdomains propagated away

We demonstrate a novel approach for fabricating vertically orientated, sub-10 nm, block copolymer (BCP) nanodomains on a substrate via molecular tailoring of poly(styrene- b -methyl methacrylate) (PS- b -PMMA) BCP, one of the most widely used BCPs for nanopatterning. The idea is to incorporate a short middle block of self-attracting poly(methacrylic acid) (PMAA) between the PS and PMMA blocks, where the PMAA middle block promotes phase separation between PS and PMMA, while maintaining the domain

Micellization behavior of (AB)n type star-block copolymer in a selective solvent for its outer block is investigated by using a Brownian dynamics simulation. Micellar properties are compared in terms of the arm number (n) of star-block copolymer. It is observed that the critical micelle concentration (cmc) shows a minimum when the cmc is plotted against the arm number. The star-block copolymer with longer soluble block shows the cmc minimum at smaller arm number than that with shorter soluble bl

A triboelectric nanogenerators (TENG) are of great interest as emerging power harvesters because of their simple device architecture with unprecedented high efficiency. Despite the substantial development of new constituent materials and device architectures, a TENG with a switchable surface on a single device, which allows for facile control of the triboelectric output performance, remains a challenge. Here, a supramolecular route for fabricating a novel TENG based on an alkali‐metal‐bound poro

It is well-known that block copolymers form spatially ordered microscopic structures under proper conditions owing to the self-assembly driven by the incompatibility between chemically linked blocks.1,2 This tendency of

The N-terminal acetyltransferase A (NatA) complex, which is composed of NAA10 and NAA15, catalyzes N-terminal acetylation of many proteins in a co-translational manner. Structurally, the catalytic subunit NAA10 was believed to have no activity toward an internal lysine residue because the gate of its catalytic pocket is too narrow. However, several studies have demonstrated that the monomeric NAA10 can acetylate the internal lysine residues of several substrates including hypoxia-inducible facto

Supramolecular assembly of functionalized polymers, capable of forming block copolymer-like molecular clusters, has emerged as a promising alternative for creating nanoscopically ordered structures. Here, we demonstrate that nanospheres, which have intriguing internal nanodomains and controllable surface functionality, can be fabricated by supramolecular assembly of two complementarily end-interacting species of mono-end-functionalized polymers using the self-organized precipitation (SORP) metho

Stimuli-interactive structural color (SC) of a block copolymer (BCP) photonic crystal (PC) uses reversible alteration of the PC using external fluids and applied forces. The origin of the diffusional pathways of a stimulating fluid into a BCP PC has not been examined. Here, we directly visualize the vertically oriented screw dislocations in a one-dimensional lamellar BCP PC that facilitate the rapid response of visible SC. To reveal the diffusional pathway of the solvent via the dislocations, BC

The phase behavior of blends of mono-end-functionalized polymers (denoted by A) and a di-end-functionalized polymer (denoted by B), capable of forming triblocklike supramolecules, is theoretically predicted by using a weak-segregation theory based on the Landau formalism. In this model system, polymers can form diblocklike or triblocklike clusters via associations between end-functionalized groups of A- and B-homopolymers. The free energies of various ordered structures including complex phases

Herein, we designed a catechol-based compound, 4-allyl pyrocatechol (APC), which contains catechol and alkene groups capable of interacting with various metal oxide substrates and being chemically incorporated into a polydimethylsiloxane (PDMS) matrix, respectively. Due to the specific interactions between the catechol and metal oxide surface, this compound incorporated in PDMS can act as a surface “active” additive that effectively enriches the adhesion interface, leading to the improvement of

Phase diagrams for reversibly associating one-end-functionalized chain molecules (with an emphasis on hydrogen bonding) are determined by computer simulations of a cubic lattice model employing canonical and grand canonical Monte Carlo methods. Due to the relatively short chain lengths used, the stability of the homogeneous state is strongly enhanced compared to mean-field random phase approximation predictions. Characteristic phenomenon such as reappearing phases and macrophase separation into