Article
Polymer Science
Keisuke Hayashi, Arihiro Kanazawa, Sadahito Aoshima
Summary: The cationic copolymerization ofo-phthalaldehyde with various styrene derivatives and vinyl ethers was investigated, with a focus on the relationship between the structure and reactivity of vinyl monomers and the copolymerization behavior. The existence of alpha or beta-substituents on the vinyl group was found to be essential for efficient crossover reactions with styrene derivatives, while various vinyl ethers underwent copolymerization with o-phthalaldehyde. The use of vinyl monomers with both large steric hindrance and highly reactive beta-carbon was effective in achieving an alternating-like copolymerization. Additionally, degradable copolymers were successfully obtained from styrene derivatives.
Article
Chemistry, Multidisciplinary
Keita Kuroda, Makoto Ouchi
Summary: This study reveals the peculiar isomerization propagation of benzyl vinyl ether with an electron-deficient acrylate in radical copolymerization. The backward isomerization of the radical species leads to a periodic consumption and allows the introduction of a benzyl ether structure in the resulting copolymer, leading to efficient degradation under acid conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Xuwen Li, Li Han, Ruixue Zhang, Chao Li, Songbo Zhang, Hongyuan Bai, Xuefei Wang, Bo Wang, Hongwei Ma
Summary: By using the LACOP method with t-BuOK and THF as additives, the regulation of sequence from statistically gradient to near periodic copolymers was achieved, and the microstructure and polymerization kinetics parameters of periodic and gradient copolymers were studied.
Article
Chemistry, Multidisciplinary
Weiben Chen, Pei Chen, Dan Chen, Yi Liu, Guang Zhang, Lei Wang, Long Chen
Summary: In this study, a strategy to design asymmetric building blocks for COF synthesis is introduced, and two isomeric hexaphenylbenzene-based two-in-one type monomers are designed and synthesized. Surprisingly, the self-polycondensation of the asymmetric monomer also forms highly crystalline COF with an identical topological structure to its symmetric counterpart. This work demonstrates the potential of using asymmetric building blocks in COF synthesis and provides a new structural design strategy for reticular chemistry.
Article
Multidisciplinary Sciences
Shuaishuai Zhu, Maoji Zhao, Hongru Zhou, Yingfeng Wen, Yong Wang, Yonggui Liao, Xingping Zhou, Xiaolin Xie
Summary: Switchable catalysis has been developed for synthesizing polymers with increasing structural complexity, but has been limited to linear block copolymers. In this study, the authors report a visible light regulated switchable catalytic system capable of synthesizing hyperbranched polymers using commercial glycidyl acrylate as a heterofunctional monomer.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Composites
Guibin Cao, Benzhang Li, Yufeng Wu, Zhibo Ren, Xiuxiu Nie, Jing Yang, Jiatao Wu, Hong Xin, Lei Wang, Chunmei Gao
Summary: The combination of one-dimensional and two-dimensional conjugated structures through random copolymerization improves the thermoelectric performance of the polymers. The power factor of P(BDTTT-DPP)1:P(DPP-EDOT)2 (P12) is the highest among the studied polymers.
COMPOSITES COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Zongfan Yang, Wenjing Hao, Xi Su, Ting Zhang, Weihua Chen, Guang Zhang, Long Chen
Summary: Increasing research interest has been raised in twodimensional covalent organic frameworks (2D COFs) due to their unique structural features and versatile functions. However, the development of 2D COFs has been limited by the relatively limited configuration of precursors. In this study, three K-shaped two-in-one building units were newly designed and synthesized, which not only had a special configuration but also incorporated metallosalphen functional moieties. These building units easily formed three new metallosalphen-based COFs with an unprecedented tju topology. Among them, Ni-Salphen-COF exhibited the highest performance in photocatalytic bromination.
CHEMISTRY OF MATERIALS
(2022)
Article
Polymer Science
Wendy Rusli, Anbanandam Parthiban, Alex M. van Herk, Song Wei Benjamin Tan
Summary: This article introduces a method of using the Monomer Addition Profile (MAP) software for semi-continuous solution polymerization to predict the optimal addition profile of less reactive comonomers in copolymers. The homogeneity of copolymers and the glass transition temperature (T-g) are discussed, along with the solubility characteristics, microstructure, and sequence length of the copolymers.
Article
Chemistry, Multidisciplinary
Yi Wan, Jianghua He, Yuetao Zhang, Eugene Y-X Chen
Summary: This work demonstrates the efficient synthesis of thermoplastic elastomers with superior mechanical properties and temperature resistance, making them potentially useful in optical devices and other applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Tiziana Fuoco
Summary: The clever combination of ring-opening polymerization (ROP) and step-growth polymerization (SGP) allows for the design of a library of sequence-controlled polymers with diverse degradability functions. This strategy offers higher chemical diversity and control over primary structure, while being simple, effective, and atom-economical.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Analytical
Jana Fortes, Michal Svingal, Tamas Porteleky, Patrik Jurik, Milos Drutarovsky
Summary: This paper proposes a sequence of steps for multi-person tracking using a single UWB radar equipped with a minimal antenna array for trilateration. Although the localization accuracy is limited, strategically placed antennas can increase detectability of multiple humans nearby and reduce computational complexity. The study demonstrates that the UWB radar, with high rate and fine range resolution, coupled with optimized processing parameters, can continually track people even when radar echoes overlap. The simplified time-of-arrival estimation and association, as well as the novel antenna height compensation method, are emphasized. The proposed framework is evaluated in an experimental scenario with three people moving closely in a small room, and the results show improved localization accuracy and target position estimation frequency.
Article
Polymer Science
Hongyan Xie, Jiabing Feng, Xiaoxia Yang, Yan Zhao, Pingan Song, Hao Wang, Zhiguang Xu
Summary: In this study, the synthesis and polymerization performance of a terpenoid-derived material were reported. With the use of an organo-base catalyst, efficient and controlled polymerization reactions with epoxides were achieved, resulting in highly structured polymers. Additionally, the self-switchable behavior of the material in a terpolymerization reaction was demonstrated.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Polymer Science
Kazuya Maruyama, Arihiro Kanazawa, Sadahito Aoshima
Summary: A one-pot synthesis method was developed for the controllable synthesis of ABC-type periodic terpolymers. The method involved the sequential-programmed cyclic monomer synthesis and living cationic copolymerization. The terpolymers exhibited controlled molecular weights, periodic sequence, molecular weight distribution, and chain ends. Additionally, the terpolymers could be degraded by acid. Furthermore, ABC-type sequence terpolymers and periodic block quaterpolymers were synthesized by the addition of different vinyl monomers.
Article
Optics
Youssef. Trabelsi, Walid. Belhadj, Naim. Ben Ali, Arafa H. Aly
Summary: The optical properties of one-dimensional periodic and quasiperiodic photonic crystals containing nematic liquid crystal layers were investigated using the transfer matrix method. It was found that the proposed ternary configuration exhibits tunable defect modes and optical microcavities, with improved sensitivity when voltage is applied to the NLC layers. In addition, applying quasiperiodic inflation according to the Rudin Shapiro Sequence scheme leads to multiple tunable resonant modes within the photonic band gap.
Article
Polymer Science
Yuki Kametani, Makoto Ouchi
Summary: A series of methacrylate/styrene alternating copolymers were efficiently synthesized via alternating copolymerization and subsequent one-pot alcoholysis transformation, showing stable monomer and reactivity towards alcohols, resulting in lower glass transition temperatures. Controlled via a RAFT polymerization system, a unique block copolymer composed of alternating copolymer segments was obtained.
Article
Chemistry, Multidisciplinary
Nagi Mizutani, Nobuhiko Hosono, Takashi Uemura
Summary: We present a novel approach to encapsulate large guest molecules in nanoporous materials, metal-organic frameworks (MOFs), via an in situ crystal formation method. This method has exciting prospects in the design of new organic/inorganic hybrids, as well as capturing and separating molecules that are significantly larger than the actual pore size of the host MOF.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Masahiro Abe, Yuki Kametani, Takashi Uemura
Summary: In this study, a new method for synthesizing double-stranded polymers was developed. By conducting crosslinking radical polymerization inside a metal-organic framework, soluble double-stranded polymers were successfully obtained. This technique has potential applications in various fields.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Takashi Kitao, Alexandre Legrand, Taizo Mori, Katsuhiko Ariga, Takashi Uemura
Summary: The orientation of polymer chains is crucial for the properties of polymeric materials. In this study, anisotropic polythiophene particles with controlled lengths were fabricated using a metal-organic framework template, resulting in the preferential alignment of unprocessable polythiophene chains.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Yuki Watanabe, Tatsuhiko Goto, Jingxin Xia, Naoki Ogiwara, Hiroyasu Tabe, Satoshi Horike, Yasuto Noda, Sayaka Uchida, Hiroshi Kageyama
Summary: We synthesized a Bi-substituted solid solution in [H10.7Sb32.1O44][H2.1Sb2.1I8O6][Sb0.76I6]2.25H2O (HSbOI), a recently discovered acid catalyst with positively charged clusters. Up to 5% of the antimony sites were substituted, resulting in an enlarged lattice and a smaller bandgap. EXAFS measurements show that the Bi cations are selectively located in the octahedral cluster. However, the Bi-substitution deteriorated catalytic properties, implying the potential of modifying characteristics of surface protons in large clusters.
Article
Polymer Science
Ami Nishijima, Yuki Hayashi, Koichi Mayumi, Nobuhiko Hosono, Takashi Uemura
Summary: This report presents a bottom-up synthesis method for a polymer-based 2D electrolyte using a metal-organic framework (MOF) as a template. Crosslinking polymerization of methyl methacrylate (MMA) within MOF nanochannels resulted in poly(methyl methacrylate) (PMMA) monosheets. Hydrolysis of the precursor polymer gave poly(methacrylic acid) (PMAA) sheets. PMAA-1 exhibited high solubility and viscous liquid-like nature when dispersed in water at a pH higher than 5.7, and the addition of Al3+ ions promoted hydrogel formation.
Article
Chemistry, Multidisciplinary
Naoya Haraguchi, Naoki Ogiwara, Yoshitaka Kumabe, Soichi Kikkawa, Seiji Yamazoe, Takashi Tachikawa, Sayaka Uchida
Summary: Size-controlled Ag clusters with specific colors were synthesized using porous ionic crystals (PICs) as scaffolds and redox-active polyoxometalates (POMs) as electron sources. The cluster size and color emission were controlled by the reduction time and types of ions or elements in the PICs. This method provides a convenient way to obtain ligand-free Ag clusters with high yields and stability.
Article
Multidisciplinary Sciences
Tomoya Iizuka, Hiroyuki Sano, Benjamin Le Ouay, Nobuhiko Hosono, Takashi Uemura
Summary: Mechanically interlocked architecture has led to the development of various molecular systems, but the focus has been primarily on the molecular-scale integrity and topology of the structures. The topological material design of such architectures at different scales has not been fully explored.
NATURE COMMUNICATIONS
(2023)
Article
Polymer Science
Xiyuan Zhang, Takashi Kitao, Ami Nishijima, Takashi Uemura
Summary: Polyacrylonitrile (PAN) nanosheets with unimolecular thickness were successfully synthesized by cross-linking polymerization in the 2D nanospaces of a metal-organic framework. The ultrathin 2D network structure inhibited crystallization and allowed for efficient thermal transformation reaction of PAN. The amorphous nature of the PAN nanosheets facilitated thermal dehydroaromatization reactions to yield a ladder polymer structure with a highly extended conjugated system. Notably, further carbonization of this ladder polymer produced graphitic carbon with a highly ordered structure due to the well-defined precursor structure.
Article
Chemistry, Physical
Hongqiang Xin, Lan Sun, Yiwei Zhao, Zhengfei Dai, Qiaomei Luo, Shengwu Guo, Danyang Li, Ya Chen, Naoki Ogiwara, Hiroshi Kitagawa, Bo Huang, Fei Ma
Summary: Polyhedral-morphology controlled rhodium phosphide (Rh2P) nano-particles with dominant {200} facets exhibit high catalytic activity in water electrolysis, even superior to Pt/C catalyst. The exposure of {200} facets is advantageous for the catalytic performance of Rh2P NPs.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Construction & Building Technology
Pengcheng Qiu, Yuya Sakai, Yuki Tamura, Naoki Ogiwara, Sayaka Uchida
Summary: A strong construction material was directly synthesized from low-quality sand through the sol-gel method. The highest strength (>25 MPa) and lowest porosity (5.79%) were achieved with 50% mass KOH and 80% v/v EtOH. The high strength was attributed to the formation of microcline and tetraethoxysilane, which resulted in a more homogenous structure and reduced porosity.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Ren Wei, Yuya Sakai, Naoki Ogiwara, Sayaka Uchida
Summary: This study investigates the microstructural changes between concrete and kraft lignin (KL) in botanical concrete (BC), and the effects of temperature and air on BC performance. The results show that condensation reactions between concrete and KL fragments are the most influential factor in improving BC strength.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Polymer Science
Ami Nishijima, Takashi Uemura
Summary: This paper presents different synthetic approaches to two-dimensional polymeric materials (2DPMs) and classifies them into three categories. Each approach can generate 2DPMs with unique features. Lastly, it discusses current challenges in synthetic design and future development directions.
Review
Chemistry, Physical
Naoki Ogiwara, Sayaka Uchida
Summary: This review discusses the catalysis of metal-oxo-cluster-based crystals, emphasizing the solidification of catalytically active metal-oxo cluster anions (polyoxometalates [POMs]) with various cations. The spatial periodicity of POMs, crucial for their catalytic properties, can be controlled through electrostatic interaction, hydrogen bonds, or coordination bonds by selecting appropriate cations. The properties of metal-oxo clusters and their counterparts can be manipulated by factors such as charge, electron configuration, ionic radius, and electronegativity of constituent elements, allowing for the construction of a wide range of crystals and the advancement of catalytic science.
Article
Chemistry, Multidisciplinary
Nanako Tamai, Naoki Ogiwara, Eri Hayashi, Keigo Kamata, Toshiyuki Misawa, Takeru Ito, Tatsuhiro Kojima, Mireia Segado, Enric Petrus, Carles Bo, Sayaka Uchida
Summary: Cation-uptake has been extensively studied in materials science. In this study, the researchers focused on a molecular crystal composed of a charge-neutral polyoxometalate (POM) capsule and discovered the occurrence of cation-coupled electron-transfer reaction. The findings reveal the significance of the POM capsule in cation uptake.
Article
Chemistry, Multidisciplinary
Wei Zhou, Naoki Ogiwara, Zhewei Weng, Congcong Zhao, Likai Yan, Yuji Kikukawa, Sayaka Uchida
Summary: This study presents the first example of a vanadium-substituted delta-Keggin Al-13-based porous Ionic crystal (PIC), which exhibits Lewis acidity. The Lewis acidity was confirmed through acetalization reaction using Al28V4-PW9V3 as a solid catalyst and investigating with pyridine or 2,6-lutidine as basic probe molecules.
CHEMICAL COMMUNICATIONS
(2022)
