A5103107393- Block Copolymer Self-Assembly
- Advanced Polymer Synthesis and Characterization
- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Polymer Surface Interaction Studies
- Pickering emulsions and particle stabilization
- Surfactants and Colloidal Systems
- Force Microscopy Techniques and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Nanofabrication and Lithography Techniques
- Machine Learning in Materials Science
- Theoretical and Computational Physics
- Advancements in Photolithography Techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Nanopore and Nanochannel Transport Studies
- Anodic Oxide Films and Nanostructures
- Polymer crystallization and properties
- Medical Imaging Techniques and Applications
- Nanomaterials for catalytic reactions
- Polymer Nanocomposites and Properties
- Vascular Malformations and Hemangiomas
- Metallic Glasses and Amorphous Alloys
- Porphyrin and Phthalocyanine Chemistry
- Thermodynamic and Structural Properties of Metals and Alloys
- User Authentication and Security Systems
Tohoku University
2012-2022
Advanced Institute of Materials Science
2010-2022
Maruho (Japan)
2017-2018
Sendai University
2015-2017
Kyushu University
2012-2016
Japan Science and Technology Agency
2012-2016
NTT (Japan)
2012
Tokyo University of Science
2004
Niigata University
2000
3D confinement effect: Block copolymers form novel phase separation structures in the nanoparticles owing to frustration of nanosized effect. Whereas films block lamellar structures, formed unique (Janus-type, tennis-ball-, mushroom-, wheel-, and screwlike structures) depending on ratio between particle diameter molecular weight.
Nanoparticles with concentric layered structures were generated from a lamellae-forming poly(styrene-b-isoprene) diblock copolymer using controlled precipitation tetrahydrofuran/water mixture. Chloroform, good solvent for both blocks, was used to swell and anneal the nanoparticles suspended in aqueous media. The three-dimensional morphologies of particles reconstructed by transmission electron microtomography throughout process annealing. A transition lamellae PI cylinders PS matrix occurred...
Divide and conquer: Polymer nanoparticles with phase-separation structures prepared block copolymers homopolymer blends were used to fabricate unique suprapolymer by cross-linking one polymer moiety dissolving the other (see scheme; PI = polyisoprene, PSt polystyrene).
Block copolymer nanopaticles were prepared from the mixture solutions containing good/poor solvents by a simple evaporation process. The block copolymers formed disorder, unidirectionally stacked lamellar, and onion-like structures in nanoparticles depending on preparation temperatures. Thermal annealing induced disorder-order phase transition order-order transformation nanoparticles, even though temperature is lower than of one polymer segment. unusual thermal behaviors suggest that glass...
Abstract Lipids and amphiphilic block copolymers spontaneously self-assemble in water to form a plethora of micelles vesicles. They are typically fluidic nature often mechanically weak for applications such as drug delivery gene therapeutics. Mechanical properties polymeric materials could be improved by forming crystalline structures. However, most the self-assembled vesicles have curved surfaces precisely tuning crystallization within nanoscale space is challenging, geometry incommensurate...
Abstract Despite recent advances in the carbonization of organic crystalline solids like metal-organic frameworks or supramolecular frameworks, it has been challenging to convert into ordered carbonaceous frameworks. Herein, we report a route attaining such via an crystal Ni-containing cyclic porphyrin dimer (Ni 2 -CPD Py ). This comprises two Ni–porphyrins linked by butadiyne (diacetylene) moieties through phenyl groups. The Ni is thermally converted covalent-organic framework at 581 K and...
Abstract Scanning electron microscopy equipped with a focused ion beam (FIB-SEM) is promising three-dimensional (3D) imaging technique for nano- and meso-scale morphologies. In FIB-SEM, the specimen surface stripped by an imaged SEM installed orthogonally to FIB. The lateral resolution governed SEM, while depth resolution, i.e., FIB milling direction, determined thickness of thin layer. most cases, superior resolution; hence, asymmetric generated in 3D image. Here, we propose new approach...
The effect of confinement on microphase-separated structures a diblock copolymer is investigated in nanoparticles serving as three-dimensional (3D) system. We succeeded preparing having various types complex from hydrophobic copolymers by simple solvent evaporation method. detailed 3D structural analysis the transmission electron microtomography (TEMT) revealed that were found only to form nanoparticle surface region, thickness which corresponded single-molecule length block bulk state....
The control of microphase-separated structures in a poly(styrene-block-butadiene-block-methyl methacrylate) (SBM) was investigated three dimensions by transmission electron microtomography. Neat SBM self-assembled into double-helical structure polybutadiene (PB) domains around hexagonally packed core polystyrene (PS) cylinders poly(methyl matrix. When PS homopolymer with lower molecular weight than that the block added to SBM, PB transformed from spherical domains, while maintaining helical...
Functionalized multiwalled carbon nanotubes (F-MWCNTs) were individually dispersed in a commercial polypropylene (PP) matrix using our well-established α-zirconium phosphate (ZrP) nanoplatelet-assisted dispersion approach. The F-MWCNTs remained uniformly PP after melt mixing and injection-molding found to remarkably enhance modulus strength at only 0.1 wt % loading. individual mostly oriented extended the flow direction shown be integrated within crystalline structure of matrix. change...
We describe here the first report for developing microphase-separated structures in poly(styrene-block-isoprene) (PS-b-PI) block copolymer nanoparticles by microwave annealing a nonsolvent, water. A random structure successfully transformed to thermodynamically stable within several minutes though it takes days using conventional thermal process.
We demonstrate that binary mixtures of small and large gold nanoparticles (GNPs) (5/15, 5/30, 10/30, 15/30 nm in diameter) the presence a glucose-terminated fluorinated oligo(ethylene glycol) ligand can spontaneously form size-segregated assemblies. The outermost layer assembly is composed single small-sized GNPs, while larger-sized GNPs are located interior, forming what referred to as yolk/shell assembly. Time course study reveals aggregate together, these kinetically trapped aggregations...
We numerically study a set of coupled Cahn–Hilliard equations as means to find morphologies diblock copolymers in three-dimensional spherical confinement. This approach allows us variety energy minimizers including rings, tennis balls, Janus balls and multipods among several others. Phase diagrams confined are presented. modify the size interface between microphases control number holes multipod morphologies. Comparison experimental observation by transmission electron microtomography...
This paper describes the first preparation of diblock-copolymer blend particles with hierarchical inner structures. AB/AC type were successfully prepared by a simple solvent evaporation method. The phase separation structures can be controlled changing molecular weight combinations common polymer segments. Furthermore, one-to-one two diblock-copolymers formed Janus different domains microphase separation. Pd ions introduced into onion-like structure. These organic–inorganic composite used as...
We show here a simple and versatile preparation method of "suprapolymer assemblies" including nanowires, nanorings, nanospheres based on the phase-separated structures formed in symmetric poly(styrene-block-isoprene) (PS-b-PI) homo-polystyrene (h-PS) blended particles. The morphological control has been performed particles by changing amounts molecular weights homopolymers. Varieties suprapolymer assemblies were prepared from these crosslinking elusion procedure.
The development of a strategy for the assembly nanoscale building blocks, in particular, anisotropic nanoparticles, into desired structures is important construction functional materials and devices. However, control over orientation rod-shaped nanoparticles on substrate integration solid-state devices remains challenging. Here, we report fabrication finely aligned gold nanorod (GNR) arrays using polymer (DNA) brushes as template. nanorods modified with cationic surface ligands were...
Three new β-carboline alkaloids, picrasidines I (I), J (II), and K (III), were isolated from the bark of Picrasma quassioides BENNET. The structures determined on basis spectral analyses chemical transformations.
Abstract In this study, metal‐polymer particles with microphase‐separated structures were prepared by self‐organized precipitation, where a good solvent is evaporated from solution that also contains block copolymer, Au NPs, and poor solvent. Control of the structure in composite consisting NPs copolymer was accomplished changing NP size, mix ratio, copolymerization ratio copolymer. The morphology inner changed lamellar phase to spherical increasing concentration. © 2011 Wiley Periodicals,...
Using a CO<sub>2</sub> continuous phase for dispersion synthesis of block copolymers can provide useful handle to control behaviour.
We investigate the formation of ordered bicontinuous structures in a stereoregular diblock copolymer, isotactic polypropylene-block-polystyrene (iPP-b-PS), which minority PP block possessed configuration. This displayed conventional double gyroid (OBDG) morphology upon heating above crystal melting point iPP from as-cast state. The OBDG phase remained stable process up to order–disorder transition. In subsequent cooling nearly disordered state, first developed, but when temperature was...
Journal Article Transmission electron microtomography in soft materials Get access Hiroshi Jinnai, Jinnai * 1Institute for Materials Chemistry and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan2Japan Science Technology Agency, ERATO, Takahara Soft Interfaces Project, Japan3International Institute Carbon-Neutral Energy Research (WPI-I2CNER), Japan *To whom correspondence should be addressed. E-mail: hjinnai@cstf.kyushu-u.ac.jp Search other works by this author...
Abstract Background There have been few reports on the efficacy and safety of oral propranolol at 3 mg/kg/day for infantile hemangioma ( IH ) in Japanese patients. Methods A multicenter, open‐label phase III study was conducted to evaluate solution infants aged 35–150 days with proliferating . Thirty‐two patients were enrolled study, received 24 weeks mg/kg/day, completed study. Results The success rate (complete or nearly complete resolution) week (primary endpoint) 78% (95% CI : 60–91%)....