Browse Articles

  • Original Article |

    We examined drug release behavior and anticancer efficacy of cyclodextrin-based nanoparticles (CDNPs) containing alpha-mangostin (MGS) in three different type of CDs (α-, β-, and γ-CD). βCDNP containing MGS demonstrated the best anticancer efficacy, while no efficacy was observed for the other CDNPs. Our findings suggested the anticancer efficacy might depend on the drug retention capability in which the interior and surface CDs in the CDNPs relate to the slow and rapid release modes, respectively. We assume the drug retention capability of slow release mode is important for performing the anticancer efficacy.

    • Van T. H. Doan
    • , Shin Takano
    • , Ngoc Anh T. Doan
    • , Phuong T. M. Nguyen
    • , Van Anh T. Nguyen
    • , Huong T. T. Pham
    • , Koji Nakazawa
    • , Shota Fujii
    •  & Kazuo Sakurai
  • Focus Review |

    Water-soluble Naphthalene diimide (NDI) binds to the DNA duplex via threading intercalation mode. This has provided unique DNA analytical techniques, functional DNA polymers, and supramolecular polymers. Especially the ferrocene-containing NDIs, having electrochemically active sites, has been applied to an electrochemical gene detection system and also utilized in the precision analysis of genes and single nucleotide polymorphisms. Recently, NDI derivatives have been recognizing as potential candidate for anticancer therapeutics and for designing a unique cancer-detection system.

    • Shigeori Takenaka
  • Rapid Communication |

    Aliphatic polycarbonate (APC) macromolecular chain-transfer agents (macro-CTAs) with an allyl end group were successfully synthesized by cobalt-catalyzed epoxide/carbon dioxide copolymerization in the presence of allyl alcohol as a chain-transfer agent. The ring-opening metathesis polymerization of cycloalkene monomers using the obtained APC macro-CTAs yielded the corresponding APC-block-polycycloalkene copolymers.

    • Yuu Nakabayashi
    •  & Koji Nakano
  • Original Article |

    The microporosity of poly(1-trimethylsilyl-1-propyne) (PTMSP) and poly(4-methyl-2-pentyne) (PMP) is investigated by two independent methods—convenient low-temperature Ar sorption and less commonly used small-angle X-ray scattering (SAXS). The Brunauer–Emmett–Teller-specific surface values obtained for PTMSP and PMP from Ar sorption isotherms correlate with the specific surface values obtained from the SAXS method. The correlation of the specific surface values obtained from fundamentally different methods makes it possible to evaluate the small-angle scattering method as adequate for assessing the microporosity of polymeric materials.

    • Samira M. Matson
    • , Natalia A. Zhilyaeva
    • , Artem V. Bakirov
    • , Sergei N. Chvalun
    •  & Valeriy S. Khotimskiy
  • Original Article |

    High-molecular-weight (HMW) benzoxazines were synthesized by Mannich condensation with various combinations of bisphenols and diamines, and the mechanical and thermal properties of the polybenzoxazines derived from the HMW benzoxazines were measured by tensile tests and thermogravimetric analysis to investigate the structure-property relationship. Among the polybenzoxazines presented in this work, the PODP-oda film derived from 4,4′-oxydiphenol and 4,4′-oxydianiline showed remarkably good mechanical properties (E = 3.7 GPa, sb = 125 MPa, and eb = 4.5%) and thermal stability (Td5 = 332 °C).

    • Yuta Murai
    • , Taichi Uemura
    • , Yujie Chen
    • , Takehiro Kawauchi
    •  & Tsutomu Takeichi
  • Original Article |

    A hyperbranched polymer (HBP) additive is used to explore short-range molecular motions in the glassy state of crosslinked epoxy amine networks via subambient β relaxations as measured by dynamic mechanical thermal analysis. Increasing HBP addition increased modulus and stress, while reducing yield strain. Pre-reaction using an isocyanate linkage between the HBP and network comparatively reduced modulus while increasing stress and strain. Glassy state mobility of the epoxy amine network as a result of HBP addition, could be directly related to many changes in mechanical properties observed.

    • Larry Q. Reyes
    • , Samuel R. Swan
    • , Houlei Gan
    • , Seyed Mohsen Seraji
    • , Jane Zhang
    •  & Russell J. Varley
  • Original Article |

    A gyroid nanostructured soft polymer film was developed by the co-organization of two types of amphiphile zwitterion monomers and a suitable acid into a bicontinuous cubic liquid-crystalline phase and subsequent in situ polymerization. The obtained polymer film showed a high ionic conductivity of 1.27 × 10–2 S cm–1 at a relative humidity of 90%.

    • Asako Maekawa
    • , Tsubasa Kobayashi
    •  & Takahiro Ichikawa
  • Original Article |

    The mechanism of intense autopolymerization reaction of 2-bromo-3-methoxythiophenes spewing brownish gas was clarified from UV-Vis, ESR, GC/MS, elemental analysis, NMR, and FT-IR spectroscopy. The reaction contained the formation of the hydrogen bromide gas during the autopolymerization. The gas induced the cleavage of the methoxy group on the thiophene ring to form the methyl bromide gas as the side reaction. This work provides an important guide for the application of the autopolymerization of thiophene derivatives to design new polymer materials.

    • Ryo Nishimura
    • , Yohei Hattori
    • , Masako Akazawa
    • , Jun-ichiro Kitai
    • , Shinichiro Okude
    • , Yuki Sakamoto
    • , Seiji Yamazoe
    • , Satoshi Yokojima
    • , Shinichiro Nakamura
    •  & Kingo Uchida
  • Original Article |

    Self-healable and cell-compatible polyurethane elastomers cross-linked by charge-transfer complexes between electron-rich pyrene (Py) and electron-deficient naphthalene diimide (NDI) were fabricated by simply blending two linear polymers with Py or NDI as a repeating unit. The elastomers with different blend ratios self-healed damage over 1 day in mild conditions, including in air and water at 30–100 °C. The good cell compatibility of the polyurethane elastomers was demonstrated by culturing two kinds of cells on the thin film substrates.

    • Keiichi Imato
    • , Hidekazu Nakajima
    • , Ryota Yamanaka
    •  & Naoya Takeda
  • Focus Review |

    This focus review describes the synthetic routes to cyclic compounds and cyclic polymers via spontaneously occurring cyclization processes using (1) rotaxane chemistry and (2) dynamic covalent chemistry. Systems with rotaxane-based structures proceed via the spontaneous and selective cyclization of two self-complementary molecules and a macromolecular rotaxane switch, which results in a topology change from linear to cyclic. Systems based on dynamic covalent chemistry use exchange reactions of bis(2,2,6,6-tetramethylpiperidin-1-yl)disulfide (BiTEMPS) units. Controlling the dynamic nature of BiTEMPS-based molecules provides cyclic topologies via spontaneously and selectively occurring cyclization processes.

    • Daisuke Aoki
  • Original Article |

    A surface-controlled cooperatively rearranging region (SCC) model mimics the segmental dynamics of supercooled liquids. By introducing surface/interface effects into the SCC model, the size-dependent dynamics of nanosized polymer materials with various geometries were predicted. The calculated glass transition temperature (Tg) and fragility for filled spheres of polystyrene coincided qualitatively with experimental observations. The results also showed that Tg(filled sphere) > Tg(filled fiber) > Tg(free-standing film) when compared at the same surface area to volume ratio, whereas for fragility, the opposite trend was found.

    • Tatsuki Nakane
    • , Yuya Tsuzuki
    •  & Takashi Sasaki
  • Original Article |

    The fabricated polymeric liquid crystal beads surfaces consist of aligned rhodamine B-derived active sites possess capacity of sensing copper ions in tested solutions. The color of the beads changed to deep pink while copper ions exist in the solutions, whereas it can be easily recycled by adding aqueous ammonia, indicating the beads applied as a powerful monitoring tool.

    • Jui-Hsiang Liu
    • , Yi-Hua Hung
    • , Ssu-Ni Lin
    • , Sergey A. Shvetsov
    • , Vladimir Yu. Rudyak
    • , Alexander V. Emelyanenko
    •  & Chun-Yen Liu
  • Original Article |

    The structural evolution of β-iPP with two different supermolecular structures during the simultaneous biaxial stretching process was studied. The two samples showed different structural evolution modes. β-hedrites exhibited violent cavitation behavior during the initial stage of deformation, but in the late stages of stretching β-hedrites formed numerous dense regions, which hindered microvoid formation and led to a poor pore size distribution. Conversely, β-spherulite generated abundant microfibrillar structures, and abundant microvoids were formed, forming a membrane with a superior pore size distribution.

    • Daoxin Zhang
    • , Lei Ding
    • , Feng Yang
    • , Fang Lan
    • , Ya Cao
    •  & Ming Xiang
  • Focus Review
    | Open Access

    Direct CO2 capture from the air (DAC), is inevitable to reduce the concentration of CO2 in the atmosphere. Recent reports of ultrahigh CO2 permeances in gas separation membranes indicate a potential of new technology for DAC (m-DAC). In this paper, we use chemical process simulation to discuss the potential of m-DAC considering the state-of-the-art performance of organic polymer membranes. Based on the analysis, we propose the target properties for separation membranes required for m-DAC with competitive energy expenses as well as the direction of future membrane development for DAC.

    • Shigenori Fujikawa
    • , Roman Selyanchyn
    •  & Toyoki Kunitake
  • Review |

    Polyhydroxyalkanoates (PHAs) are biobased and biodegradable materials. The artificial PHAs, such as lactate-based polymers, synthesized by engineered platforms expand the range of physical properties. The artificial polymers with superior properties are produced mainly from CO2-derived biomass using microbial platform with engineered enzymes. The oligomers can be secreted from cells and derivatized into high-molecular-weight polymers through assembling with other segments. The review summaries recent advances in the biosynthesis and biodegradation of artificial PHAs and oligomers.

    • Seiichi Taguchi
    •  & Ken’ichiro Matsumoto
  • Original Article |

    Bacteria possibly capable of polyhydroxyalkanoate synthesis from lignin were investigated by genomics and chemistry of biomaterials. Aquitalea sp and Ralstonia pickettii isolated from a blackwater lake rich humic substances, showed great potential to be developed for this purpose. Canonical lignin degradation pathways, such as protocatechuate 4,5-dioxygenase-dependent pathway, CoA-dependent non-β-oxidation pathway of ferulic acid and β-ketoadipate pathway were mapped in their genomes. In addition, traces of P(3HB) were found when using vanillic and gallic acids as sole carbon source, which indicates that the downstream β-ketoadipate pathway is functional.

    • Lorena M. Castro
    • , Choon Pin Foong
    • , Mieko Higuchi-Takeuchi
    • , Kumiko Morisaki
    • , Eraldo F. Lopes
    • , Keiji Numata
    •  & Adolfo J. Mota
  • Review |

    To shift from a petroleum-dependent society to a sustainable society using eco-friendly materials, polysaccharides from natural products are important candidates as alternative materials. We have researched one of the cyanobacterial polysaccharides, “sacran,” which is extracted from Aphanothece sacrum. In this review, the unique characteristics, structures, and preparation of sacran LC gels are introduced. These matters are discussed especially from the perspectives of polymer science, colloidal science, gel science, etc. We hope that sacran will be used in a variety of fields, such as tissue engineering, pharmacodynamics, and biomedical materials, with possible contributions to the development of a sustainable material society.

    • Kosuke Okeyoshi
    • , Maiko K. Okajima
    •  & Tatsuo Kaneko
  • Rapid Communication |

    Ralstonia eutropha is a hydrogen-oxidizing chemolithotrophic bacterium that can synthesize poly[(R)-3-hydroxybutyrate] [P(3HB)], which can be used as a biodegradable plastic. Various genes for carbonic anhydrase involved in CO2 fixation are present in the genome of R. eutropha. In this study, we investigated the gene dosage effect of the β-carbonic anhydrase (can) gene on P(3HB) accumulation in R. eutropha under autotrophic and mixotrophic conditions.

    • Romeo Thorbecke
    • , Masahiro Yamamoto
    • , Yuki Miyahara
    • , Mino Oota
    • , Shoji Mizuno
    •  & Takeharu Tsuge
  • Original Article |

    Polyhydroxyalkanoate (PHA) is a biopolyester similar to some commodity plastics. The production cost of PHA is high partly due to the cost of feedstock. Spent bleaching clay (SBC) is a byproduct of the palm oil refining process. Adsorbed residual oil in SBC was successfully utilized by Cupriavidus necator Re2058/pCB113 in shaken flask culture for PHA production. Both the SBC and the resulting PHA were characterized by SEM, rheometer, TGA, DSC, GC and 1H-NMR to demonstrate the production of a PHA copolymer containing 3-hydroxyhexanoate.

    • Nabila Husna Bt Mohamad Hairudin
    • , Shangeetha Ganesan
    •  & Kumar Sudesh
  • Original Article |

    Inspired by the natural spinning process, we developed an aqueous spinning system with a citrate/polyethylene glycol buffer for highly extensible silk fibers. This system enabled tuning of the induction of crystallization through the buffer conditions.

    • Jianming Chen
    • , Yoshinori Ohta
    • , Hiroyuki Nakamura
    • , Hiroyasu Masunaga
    •  & Keiji Numata
  • Original Article |

    Carboxylated butyl rubber derivatives were obtained by reacting the isoprene units in the isobutylene copolymer with alkylmercaptanoic acids comprising alkyl spacers of different lengths. The yield of the reactions varied from 80 to 90% for direct reaction of the copolymer containing 1,4-isoprene units, but increased to 90–98% if the 1,4-units were isomerized to terminal alkenes prior to the reactions.

    • Vishnu D. Deepak
    • , Eda Gungör
    •  & Mario Gauthier
  • Note |

    A series of ester-functionalized polythiophenes (P3OETs) with precisely controlled head-to-tail (HT) ratios was synthesized via palladium-catalyzed direct arylation polycondensation (DArP). The ionization potentials and optical bandgaps of P3OETs decreased as their HT ratios increased because of the increased backbone coplanarity and extensive π-electron delocalization. The method of precisely controlling the regioregularity and HT ratio can contribute to the design of new polythiophene derivatives with enhanced electronic functionality.

    • Taiki Menda
    • , Tatsuya Mori
    •  & Takuma Yasuda
  • Focus Review
    | Open Access

    Our recent studies on the cellulose nanofibrils (CNFs)/polymer nanocomposites prepared via Pickering emulsion templating are reviewed. CNF-stabilized monomer-in-water emulsions were used as starting materials to design the composite structures. In the first part of this review, we summarize the preparation of transparent films. The second part describes the approaches to prepare a composite microparticles having CNF shells.

    • Shuji Fujisawa
  • Original Article |

    RAFT aqueous emulsion polymerization of vinyl acetate (VAc) was performed using poly[di(ethylene glycol) vinyl ether] (PDEGV) macromolecular chain transfer agents. The emulsion polymerization directly induced PDEGV-b-PVAc diblock copolymer assemblies in water. Owing to the characteristic PDEGV as a highly hydrophilic steric stabilizer, this facile formulation enables the production of various particle morphologies, such as spheres, rods (ellipsoids), and vesicles, depending on the composition of the block copolymer. Each morphology change in the nanoparticles via RAFT aqueous emulsion polymerization owes its success to the recent RAFT polymerizations of vinyl ethers.

    • Shinji Sugihara
    • , Ryuya Kawakami
    • , Satoshi Irie
    •  & Yasushi Maeda
  • Original Article |

    Amine-containing microgel particles (GPs), which capture CO2 at a low temperature and desorb it upon a mild heating, are attractive materials for capturing CO2. In this paper, the effect of pKa of ammonium ions in the GPs on the amount of CO2 desorption upon heating was investigated at various CO2 concentrations by experiments and thermodynamic predictions. A guideline for designing thermoresponsive amine absorbents for various applications including direct air capture and carbon recycling in closed spaces, such as space stations and submarines, is provided.

    • Ryutaro Honda
    • , Akira Hamasaki
    • , Yoshiko Miura
    •  & Yu Hoshino
  • Original Article |

    We chose an autoinduction (IPTG-independent) system for overexpression of recombinant proteins using E. coli as the expression host. In autoinduction, glucose and lactose are used as main carbon sources for cell growth. When the glucose is almost completely consumed as the first growth of E. coli., the carbon source turns to lactose, accompanied by regioselective chemical transformation of lactose to allolactose, which acts as the trigger for activation of transcription by releasing the repressor. Using this system, we achieved marked overexpression of the biosynthesized GFP and aECM-CS5-ELF.

    • Kaho Kataoka
    •  & Akinori Takasu
  • Review |

    To establish a sustainable material production system and preserve the Earth’s environment, “biomass plastics” that are made from renewable biomass instead of petroleum and “biodegradable plastics” that are completely degraded into carbon dioxide and water by enzymes secreted by microorganisms in the environment are desirable products. This miniature review describes a series of studies on microbial polyesters and polysaccharide ester derivatives, including the synthesis of novel polymers, development of new processing techniques for high-performance films and fibers, elucidation of the relationship between structure and properties using synchrotron radiation, and control of the rate of enzymatic degradation.

    • Tadahisa Iwata
    • , Hongyi Gan
    • , Azusa Togo
    •  & Yuya Fukata
  • Focus Review |

    Our recent studies on how nanostructures can be self-assembled in discotic liquid crystals to create self-organizing functional systems of discotics with tuned physical properties are reviewed. In the first part of the article, charge carrier and semiconducting properties of discotic liquid crystals in the form of 1-D molecular wires are described. The second part of this report summarized our recent results on self-assembly of Ag, Au, Cu, and graphene nanoparticles, carbon dots, CdTe and CdSe quantum dots, gold nanorods, CdS nanoribbons, silver nanodisks, and graphene sheets in discotics.

    • Manish Kumar
    • , Shalaka Varshney
    •  & Sandeep Kumar
  • Focus Review |

    Recent studies on exploration of mechanical deformation of microtubules under tensile and compressive stress, using a newly developed methodology, have been reviewed. In the first part of this review article, development of the methodology and its utility in studying the mechanoresponsiveness of microtubules have been described. In the second part, applications of the recently developed methodology in studying dynamic soft interfaces have been elaborately discussed.

    • Arif Md. Rashedul Kabir
    •  & Akira Kakugo
  • Note |

    Poly(γ-glutamic acid) (PGA) is a biopolymer produced by Bacillus spp. via the γ-amide linkages of d- and/or l-glutamate. PgsB, PgsC, and PgsA are the minimum protein set required for PGA production in B. subtilis, and PgsE improves PGA productivity. Analysis by size-exclusion chromatography combined with multiangle laser light scattering revealed that the molecular weight of PGA was Mw = 2,900,000 g mol−1 or predominantly Mw = 47,000 g mol−1 in preparations derived from B. subtilis cells with or without pgsE, respectively. PgsE may be required to increase the apparent molecular weight of PGA.

    • Ken-Ichi Fujita
    • , Takashi Tomiyama
    • , Takahiro Inoi
    • , Takashi Nishiyama
    • , Eriko Sato
    • , Hideo Horibe
    • , Ryosuke Takahashi
    • , Shinichi Kitamura
    • , Yoshihiro Yamaguchi
    • , Akira Ogita
    •  & Toshio Tanaka
  • Focus Review |

    Our recent studies on the zincate complex dilithium tetra-tert-butylzincate-catalyzed transesterification and polymerization are reviewed. In the first part of this report, the ROP of ε-caprolactone catalyzed by TBZL is described. In the second part of this report, the acylation and transesterification of alcohols with vinyl acetate and carboxylic esters catalyzed by TBZL are summarized. Next, TBZL-catalyzed polycondensations of diphenyl carbonate (DPC) with diols are discussed. In the last part of this report, the transesterifications of poly(phenyl methacrylate) (PPhMA) side chains with alcohols catalyzed by TBZL are described.

    • Miyuki Oshimura
  • Original Article |

    The present study described a new method with one step to fabricate silk fibroin nano- and microspheres, with the size of spheres and crystalline structure being controllable during processing. Silk microspheres prepared in the presence of salts were less porous and more homogeneous in size than those prepared in the absence of salts (Control). These properties are important not only for the stabilization of particles but also for the controlled release of entrapped drug molecules.

    • Jianbing Wu
    • , Wenjun Guo
    • , Lixiang Zhang
    • , Yongfeng Wang
    • , Leigen Liu
    • , Wei Wang
    • , Yinyin Sun
    • , Jin Tao
    •  & Xiaoqin Wang
  • Focus Review |

    We reviewed our recent studies on optical manipulation techniques for microspectroscopic analysis of optically trapped polymers. A focused laser beam exerts an optical force on polymer chains, leading to the microassembly formation of them. We applied the conventional optical tweezers for the concentration determination techniques of phase-separated thermoresponsive polymer chains by combining with microspectroscopies. To overcome the limitations of the conventional optical tweezers, localized surface plasmon has attracted much attention. Finally, we introduced our original manipulation technique based on nanostructured semiconductor-assisted optical tweezers; NASSCA optical tweezers.

    • Tatsuya Shoji
    •  & Yasuyuki Tsuboi
  • Original Article |

    A highly random terpolymer of CO2, styrene oxide (SO), and propylene oxide (PO) was realized by using a tetraphenylporphyrinatocobalt(III) chloride ((TPP)CoCl)/4-dimethylamino pyridine (DMAP) catalyst system. In contrast, gradient terpolymers were formed in the cases of CO2, cyclohexylethylene oxide (CyEO), tert-butylethylene oxide (tBuEO) or 1-adamantylethylene oxide (AdEO), and PO. The glass transition temperatures (Tgs) of these terpolymers are tunable between that of the copolymer of CO2 with PO (34 °C) and that of the copolymers of CO2 with the corresponding epoxide with bulky side groups.

    • Masayoshi Honda
    • , Takuya Ebihara
    • , Tomoya Ohkawa
    •  & Hiroshi Sugimoto
  • Original Article |

    Latex films typically suffer from poor mechanical strength compared to solution-cast latex films. In the present study, to obtain tougher latex films, we investigated the relationship between the mechanical properties and the nanostructures of films prepared at different film-formation temperatures (FFTs), i.e., FFTs above and below the glass-transition temperatures (Tg) of the microspheres. Tensile tests revealed that the films showed the highest fracture energies when the film was formed at a temperature higher than the Tg of the microspheres and followed by annealing.

    • Seina Hiroshige
    • , Haruka Minato
    • , Yuichiro Nishizawa
    • , Yuma Sasaki
    • , Takuma Kureha
    • , Mitsuhiro Shibayama
    • , Kazuya Uenishi
    • , Toshikazu Takata
    •  & Daisuke Suzuki
  • Focus Review |

    The chain-growth polymerization mechanism is essentially unsuitable for sequence control due to its statistical propagation feature. However, the development of reversible-deactivation radical polymerization has opened the door to the sequence control. Our group has developed some methodologies and concepts for the synthesis of sequence-controlled oligomers/polymers via radical polymerization: it is crucial to introduce some additional components into the initiator and/or the monomer for reversible-deactivation radical polymerization and in most cases these components are designed to be removed or transformable afterward.

    • Makoto Ouchi
  • Note |

    We prepared the chemically crosslinked, cylindrical thermoresponsive poly(N-isopropylacrylamide) gels with changing the contents of reversible addition-fragmentation chain transfer (RAFT) agent. The environment in the gel was estimated by using a hydrophobic fluorescence probe. While the equilibrium swelling ratios were comparable, the deswelling response became fast as the content of RAFT agent increased with the formation of “bubble pattern”. This result indicates that the PNIPAAm gels prepared by RAFT still have spatial defects. In addition, the cooperative diffusion coefficients in swelling process of the gels prepared by RAFT polymerization were estimated.

    • Tsukuru Masuda
    •  & Madoka Takai
  • Review
    | Open Access

    Biodegradable plastics are gaining attention as one of the solutions to marine plastic wastes, which are increasing every year. Among them, polyhydroxyalkanoate (PHA) and polycaprolactone (PCL) are known to exhibit particularly good marine biodegradability. In this review, to understand their excellent marine biodegradability, the biosynthesis of PHA and cutin, a natural analog of PCL, and the biodegradation of PHA and PCL in the carbon cycle in marine ecosystems are described.

    • Miwa Suzuki
    • , Yuya Tachibana
    •  & Ken-ichi Kasuya
  • Original Article |

    Natural rubber-grafted-polyaniline with nanomatrix structure was prepared through graft-copolymerization. The effect of parameters on the graft-copolymerization was investigated using factorial experimental design and univariate experiments. The structural characterization of the resulting materials through NMR spectroscopy confirmed that aniline was grafted on the natural rubber. As observed in TEM image, polyaniline, which covered the natural rubber particles, formed the nanomatrix, and natural rubber particles formed the dispersed phase. The thermal properties and electrical conductivity of natural rubber-grafted-polyaniline were improved by the formation of nanomatrix structure.

    • Thu Ha Nguyen
    • , Thi Thuy Tran
    • , Seiichi Kawahara
    •  & Toshiaki Ougizawa
  • Original Article |

    Poly(vinyl butyral) (PVB) is accepted as an adhesive to glass substrates. The PVB was prepared through butyralization of poly(vinyl alcohol) under supercritical carbon dioxides. The Young’s modulus and tensile strength of the PVB prepared under supercritical carbon dioxides were higher than those of the PVBs in the preparation method in solution and swollen states. In addition, the PVB under supercritical carbon dioxide possessed higher adhesive strength to glass substrates even under high humid condition, compared with the other PVBs.

    • Takuya Matsumoto
    • , Miyabi Yorifuji
    • , Yuya Sugiyama
    •  & Takashi Nishino
  • Focus Review |

    Carbon dioxide capture and storage (CCS) technology has become important due to the threat of global warming and climate change. Furthermore, the development of carbon dioxide capture and utilization (CCU) technology, which reuses the captured CO2, has been prioritized in recent years to accelerate the deployment of “CCUS.” Amine-based CO2 capture is a key process for realizing a carbon neutral society.

    • Hidetaka Yamada
  • Original Article |

    Two novel supramolecular norbornene monomers were prepared according to β-cyclodextrin–ferrocene (/adamantane) host–guest interactions and exhibited both the “living” and “controlled” ROMP characteristics with the aid of the third-generation Grubbs’ catalyst for the construction of corresponding supramolecular homopolymers and diblock copolymers.

    • Bin Song
    • , Li Zhang
    • , Honglei Yin
    • , Hongming Liang
    • , Jinwei Zhang
    •  & Haibin Gu
  • Review
    | Open Access

    This article reviews an evaluation-oriented exploration of photo energy conversion systems including organic photovoltaics, perovskite solar cells, photocatalysts, and photodetectors. A time-resolved spectroscopy using a gigahertz electromagnetic wave enables rapid screening of potential optoelectronics of organic/inorganic semiconductors and fast finding of their optimal film processing conditions. This approach is further empowered by machine learning that provides a high-throughput virtual screening in the large molecular space. The author discusses a perspective on this evaluation (from fundamental to application) and its effective combination with data science.

    • Akinori Saeki
  • Original Article |

    Plasticized poly(ethylene carbonate) (PEC)/LiPF6 electrolytes were prepared and evaluated their ion-conductive and dielectric relaxation behavior using broadband electric spectroscopy (BES). The BES results indicated that the plasticizer accelerates segmental motion of PEC and improve the dc conductivity, and the plasticizing effect of ionic liquid (EMImTFSI) on the PEC electrolyte is larger than that of glycerol. From the results of the Walden plot and fragility analysis, it was revealed that the degree of decoupling and the value of fragility increase by the addition of plasticizer, and these plasticizers weaken interactions between PEC chains and Li ions in the electrolyte.

    • Kaori Kobayashi
    • , Gioele Pagot
    • , Keti Vezzù
    • , Federico Bertasi
    • , Vito Di Noto
    •  & Yoichi Tominaga
  • Review |

    The use of iron catalysts in CO2/epoxide chemistry has been less explored compared with zinc, cobalt, and chromium catalysts. This review highlights recent examples including iron complexes that deoxygenate epoxides in situ and geometry-dependent selectivity towards either polycarbonate or cyclic carbonate production. Reaction conditions (temperature, CO2 pressure, and amount of nucleophilic cocatalyst) and catalyst structure are all critical in accessing efficient catalysis for polycarbonate formation.

    • Kori A. Andrea
    •  & Francesca M. Kerton
  • Original Article |

    Photocontrolled ring-opening polymerization of lactones with the advantages of being inexpensive, green, and noninvasive, is still rarely reported. In this work, we developed a series of composite photoacid generators containing a common photocatalyst and an onium salt to induce the living/controlled cationic ring-opening polymerization of lactones using alcohol compound as an initiator under visible light. The wavelength of the light could be easily adjustable by applying different photocatalysts. Moreover, simultaneous living/controlled cationic ring-opening polymerization of lactones and reversible addition–fragmentation chain transfer radical (RAFT) polymerization of methyl acrylate can be performed using hydroxy group capped trithiocarbonate to produce hybrid block copolymers in one step.

    • Lei Xia
    • , Ze Zhang
    •  & Ye-Zi You
  • Original Article |

    The effect of the ionic liquid content in tough inorganic/organic double-network (DN) ion gel membrane on the CO2 permeability was investigated. By optimizing the composition of the inorganic and organic networks, the mechanical strength of the DN ion gel was significantly increased, and the DN ion gel membrane with more than 95 wt% of an ionic liquid was successfully prepared. With the increase in the ionic liquid content, the CO2 permeability of the DN ion gel membrane exponentially increased up to ~67% of the theoretical maximum CO2 permeability.

    • Eiji Kamio
    • , Masayuki Minakata
    • , Yu Iida
    • , Tomoki Yasui
    • , Atsushi Matsuoka
    •  & Hideto Matsuyama
  • Note |

    The synthesis of 100% 13C-labelled poly(propylene carbonate) from the completely alternating copolymerization of propylene oxide (rac-PO and R(+)PO) and 13CO2 is reported. The prepared copolymers were shown to be regioselective with predominately head-to-tail (HT) connectivity. The infrared absorption of the polycarbonate in the $$v_{{\mathrm{co}}_{\mathrm{3}}}$$vco3 region is red-shifted by 45 cm−1 from the polymer prepared from 12CO2. This shift in frequency allows for the observation of vNO modes of incorporated dinitrosyl metal complexes.

    • Gulzar A. Bhat
    • , Marcetta Y. Darensbourg
    •  & Donald J. Darensbourg