Article
Polymer Science
Jianing Zhou, Jinxian Yang, Muhammad Waqas Ishaq, Lianwei Li
Summary: The study explores the difference in topology-structure-conformation relationship between linear and cyclic graft polymers, showing that cyclic graft polymers exhibit more compact conformation and suppress interchain association compared to linear graft polymers.
Article
Polymer Science
Yuya Doi, Atsushi Takano, Yoshiaki Takahashi, Yushu Matsushita
Summary: The study found that dumbbell polymers form a unique network structure with distinctive entanglement characteristics in the system. Dumbbell PS samples with longer central chains exhibit slower terminal relaxation and retain entanglement features in high-concentration DOP solutions.
Article
Chemistry, Physical
Khristine Haydukivska, Viktoria Blavatska, Jaroslaw Paturej
Summary: We investigated the conformational properties of a hyper-branched polymer structure called snowflake polymer, which has a dendrimer-like topology. Through analytical methods and numerical simulations, we found that as the number of branching points increases, the polymer becomes more compact in conformation. This study provides valuable insights into the conformational behavior of snowflake polymer and emphasizes the impact of branching parameters on its overall compactness.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Multidisciplinary Sciences
Junki Tanaka, Zaihong Yang, Stefan Typel, Satoshi Adachi, Shiwei Bai, Patrik van Beek, Didier Beaumel, Yuki Fujikawa, Jiaxing Han, Sebastian Heil, Siwei Huang, Azusa Inoue, Ying Jiang, Marco Knosel, Nobuyuki Kobayashi, Yuki Kubota, Wei Liu, Jianling Lou, Yukie Maeda, Yohei Matsuda, Kenjiro Miki, Shoken Nakamura, Kazuyuki Ogata, Valerii Panin, Heiko Scheit, Fabia Schindler, Philipp Schrock, Dmytro Symochko, Atsushi Tamii, Tomohiro Uesaka, Vadim Wagner, Kazuki Yoshida, Juzo Zenihiro, Thomas Aumann
Summary: The study of alpha cluster formation on the surface of neutron-rich heavy nuclei using quasi-free alpha cluster-knockout reactions reveals a tight interplay with the neutron skin thickness. This result calls for a revision in the correlation between neutron-skin thickness and the density dependence of the symmetry energy, crucial for understanding neutron stars. Additionally, the observed monotonous decrease of reaction cross sections with increasing mass number provides a natural explanation for the origin of alpha particles in alpha decay.
Article
Engineering, Mechanical
Yoshinori Sawae, Takehiro Morita, Kyota Takeda, Shugo Onitsuka, Jyo Kaneuti, Tetsuo Yamaguchi, Joich Sugimura
Summary: PTFE composites with different filler materials exhibit different tribological characteristics in gaseous hydrogen. Glass fiber causes severe abrasion on the cast iron sliding counterface, while carbon fiber-filled composites show excellent low friction and low wear performance.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Mechanics
Manisha Handa, Parbati Biswas
Summary: This study theoretically investigates the intramolecular relaxation dynamics of unconcatenated ring polymers in dilute solutions, finding that excluded volume interactions can decrease relaxation rates and expand the width of the relaxation spectrum.
JOURNAL OF RHEOLOGY
(2021)
Article
Polymer Science
Yuya Doi, Jinya Kitamura, Takashi Uneyama, Yuichi Masubuchi, Atsushi Takano, Yoshiaki Takahashi, Yushu Matsushita
Summary: In this study, the viscoelastic properties of comb-shaped ring polystyrene samples with different branch chain lengths were examined. The results showed that even samples with the shortest branch chains exhibited intermolecular branch chain entanglement. The effects of different backbone molecular structures on the terminal relaxation behavior were discussed.
Article
Chemistry, Physical
Daniela Filip, Adina Maria Dobos, Anca Filimon, Doina Macocinschi, Anca Giorgiana Grigoras
Summary: The solution behavior of new star poly(ether urethane)s based on erythromycin propionate core was studied by viscometry at different concentrations and temperatures in N,N-dimethyl formamide. The impact of chemical structures, molecular weights, solvent, temperature, and system interactions on the viscosities and dimensions of the polymer chain in dilute solution was investigated.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Polymer Science
Esra Altun, Jubair Ahmed, Mehmet Onur Aydogdu, Anthony Harker, Mohan Edirisinghe
Summary: PCL microparticles and fibers were separately produced by changing key operating parameters of EHD and PG systems and PCL solution properties. The use of binary solvent systems altered particle morphologies and diameters, while increased pressure and the use of different solvents greatly affected the characteristics of resulting fibers.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Polymer Science
Esra Altun, Jubair Ahmed, Mehmet Onur Aydogdu, Anthony Harker, Mohan Edirisinghe
Summary: Polycaprolactone (PCL) is a widely used material in various applications to address global health problems. By changing key operating parameters and solution properties, PCL microparticles and fibers can be separately produced. The morphology of PCL is found to be highly dependent on solvents and operating parameters.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Engineering, Chemical
Hongyun Wang, Chuncheng Li, Qian Xu, Changlin Liu, Zhonglin Zhang, Xiao Du, Xiaogang Hao, Guoqing Guan
Summary: The PEBA/PVDF composite membrane shows excellent performance in the separation of aniline, achieving high permeation flux and separation factor at high concentrations and temperatures, making it suitable for wastewater treatment.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Chemistry, Analytical
Yuanpeng Liu, Yingning Wang, Wenpu Geng, Wenqian Zhao, Hao Zhang, Weigang Zhang, Zhongqi Pan, Yang Yue
Summary: A graded-index ring-core fiber with a GeO2-doped silica ring core and SiO2 cladding is designed to enhance the purity of the orbital angular momentum (OAM) mode. The proposed fiber improves the purity of the OAM(1,1) mode from 86.48% to 94.43% by changing the high-index ring core to parabolic graded-index profile. It exhibits a flexible structure to meet different requirements in mode-division-multiplexed optical communication systems.
Article
Chemistry, Multidisciplinary
Jingyi Li, Zhenyu Zhang, Guangliu Ran, Xiaoyun Xu, Cai'e Zhang, Wenlong Liu, Xinming Zheng, Dawei Li, Xinjun Xu, Yahui Liu, Zheng Tang, Wenkai Zhang, Zhishan Bo
Summary: Motivated by simplifying the synthesis of nonfullerene acceptor and establishing the relation between molecular structure and photovoltaic performance, this study designed and synthesized two isomeric nonfused ring electron acceptors with different side chains. The results showed that the acceptor with V-shaped side chain exhibited better solubility, ordered packing, and charge transport, leading to a higher power conversion efficiency compared to the acceptor with a linear side chain.
Article
Energy & Fuels
Xin Zhang, Huazhou Li, Nobuo Maeda
Summary: This study experimentally investigated the influence of eight salt solutions on the nucleation rate of ice and found that some monovalent salts can increase the nucleation rate of ice at low supercoolings, regardless of the salt concentrations. This finding is in contrast to the previous research on clathrate hydrate nucleation mechanisms.
Article
Chemistry, Multidisciplinary
Dmitry V. Matyushov
Summary: A theory for the nonlinear dielectric response of dilute protein solutions is presented, which shows that the field-dependent dielectric function of the protein solution changes linearly with the electric field squared. The dependence is determined by the protein dipole moment, volume fraction, and the second osmotic virial coefficient. Under practical conditions, the nonlinear dielectric response is strongly correlated with the protein dipole moment and concentration.
Article
Chemistry, Multidisciplinary
Tsukasa Miyazaki, Noboru Miyata, Tessei Yoshida, Hiroshi Arima, Yoshihiro Tsumura, Naoya Torikai, Hiroyuki Aoki, Katsuhiro Yamamoto, Toshiji Kanaya, Daisuke Kawaguchi, Keiji Tanaka
Article
Polymer Science
Jin-Hyeok Hong, Masayasu Totani, Daisuke Kawaguchi, Norifumi L. Yamada, Hisao Matsuno, Keiji Tanaka
Summary: Surface modification of polymeric materials, using a bottlebrush-type structure, allows for control of physical and chemical properties without altering bulk characteristics. The extent of surface segregation is more pronounced for P[O(Ox)(7)MA] compared to P[O(Ox)(19)MA], with a thicker diffused interface formed in water, leading to stronger suppression of cell adhesion and protein adsorption.
Article
Physics, Applied
Tatsuki Abe, Daisuke Kawaguchi, Motonori Watanabe, Taiki Hoshino, Tatsumi Ishihara, Keiji Tanaka
Summary: The study demonstrated how the out-of-plane hole mobility in P3HT changes with decreasing film thickness, attributing the decrease in mobility to an increase in energetical and spatial distribution of hopping sites caused by crystallographic distortion in the thin films. Grazing incidence wide-angle X-ray diffraction measurements confirmed the induced distributions of charge carriers.
APPLIED PHYSICS LETTERS
(2021)
Article
Multidisciplinary Sciences
Zhiwei Hao, Asieh Ghanekarade, Ningtao Zhu, Katelyn Randazzo, Daisuke Kawaguchi, Keiji Tanaka, Xinping Wang, David S. Simmons, Rodney D. Priestley, Biao Zuo
Summary: Many emerging materials, such as ultrastable glasses, owe their properties to a gradient of enhanced mobility at the surface of glass-forming liquids. This surface mobility enhancement has reshaped our understanding of glass formers behavior, especially in polymeric glasses with a two-scale nature of glassy polymer surfaces. The emergence of a transient rubbery surface behavior in polymers with short chains is driven by superposed gradients in segmental dynamics and chain conformational statistics, leading to a breakdown in time-temperature superposition.
Article
Polymer Science
Daisuke Kawaguchi, Kazuki Sasahara, Daiki Saito, Mitsugu Uejima, Hirotada Fujiwara, Shin Nishimura, Satoru Yamamoto, Keiji Tanaka
Summary: Composites of fluoropolymers (FKMs) and nanocarbon fillers have been considered as sealing materials for hydrogen fuel storage. The research found that the glass transition temperatures for FKMs adsorbed onto SWCNTs and CB were higher than the bulk value, with a more remarkable extent for SWCNTs. The difference in FKM mobility between the two fillers was attributed to the manner of chain adsorption via atomic-scale surface roughness, rather than surface chemistry.
Article
Chemistry, Multidisciplinary
Kento Kawabata, Masayasu Totani, Daisuke Kawaguchi, Hisao Matsuno, Keiji Tanaka
Summary: A novel strategy using inkjet drawing of silica nanoparticles was proposed to regulate the mechanical properties of a polymer film at the water interface, resulting in surface heterogeneity and selective cell adhesion.
Article
Polymer Science
Tatsuki Abe, Hironao Shimada, Taiki Hoshino, Daisuke Kawaguchi, Keiji Tanaka
Summary: This study demonstrates the application of SFG spectroscopy for investigating molecular orientation in polymer films, successfully identifying the difference in orientation of lamellar fibrils. SFG chemical mapping was also performed to analyze the difference in absorption wavelengths of methylene groups in the two samples.
Article
Chemistry, Physical
Weizhao Ren, Xin Wang, Jiahui Shi, Jianquan Xu, Hidenobu Taneda, Norifumi L. Yamada, Daisuke Kawaguchi, Keiji Tanaka, Xinping Wang
Summary: The adsorbed layer on a solid surface has a complex influence on the dynamics of nanoconfinement polymer materials. This study reveals that the thickness and molecular weight of the adsorbed layer strongly affects the segmental dynamics of supported thin polymer films.
Article
Polymer Science
Lu Bai, Pan Luo, Xudong Yang, Jianquan Xu, Daisuke Kawaguchi, Cuiyun Zhang, Norifumi L. Yamada, Keiji Tanaka, Wei Zhang, Xinping Wang
Summary: This study investigated the influence of interfacial effects on the glass transition temperature of polymer ultrathin films modified with a cross-linked layer. The results showed that the glass transition temperature increased with decreasing film thickness and higher cross-linking density. The chains diffused through nanolevel voids in the cross-linked layer, leading to topological constraints and reduced mobility. This research provides an opportunity to tailor interfacial effects for potential applications in polymer nanocomposites.
Article
Polymer Science
Manabu Inutsuka, Hirohmi Watanabe, Masaru Aoyagi, Norifumi L. Yamada, Chisa Tanaka, Takayuki Ikehara, Daisuke Kawaguchi, Satoru Yamamoto, Keiji Tanaka
Summary: The study showed that the presence of oligomers in PS reduced the interfacial entanglement between free chains and bulk chains in the adsorbed layer, leading to a decrease in shear bond strength despite having a similar adsorbed layer thickness to neat PS.
Article
Polymer Science
Daisuke Kawaguchi, Ayano Higasayama, Yudai Ogata, Taizo Kabe, Yushu Matsushita, Keiji Tanaka
Summary: This study investigates the effects of aggregation states and thermal molecular motion on photocarrier formation in monodispersed polymer thin films. The results suggest that crystalline ordering plays a crucial role in the formation of photocarriers in P3HT.
Article
Polymer Science
Daisuke Kawaguchi, Reika Nakayama, Hiroki Koga, Masayasu Totani, Keiji Tanaka
Summary: Polymer adhesion with inorganic materials is crucial for material diversification. By controlling the interaction between loosely-adsorbed chains and bulk free chains, interfacial adhesion can be improved. Our study shows that chemically cross-linking the loosely-adsorbed chains enhances interfacial strength. This finding has promise for the design of interfacial adhesion and composite materials.
Article
Chemistry, Physical
Ko Yamaguchi, Daisuke Kawaguchi, Noboru Miyata, Tsukasa Miyazaki, Hiroyuki Aoki, Satoru Yamamoto, Keiji Tanaka
Summary: A better understanding of the chemical reaction between epoxy and amine compounds at a solid interface is crucial for designing and fabricating materials with appropriate adhesive strength. In this study, the curing reaction kinetics of epoxy phenol novolac and 4,4'-diaminodiphenyl sulfone at the outermost interface were examined using various techniques. The results showed that the reaction rate constant was higher at the interface, and the frequency factor at the interface was also greater, which could be explained by the densification and orientation of reactants at the interface.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Rei Harada, Daisuke Kawaguchi, Satoru Yamamoto, Keiji Tanaka
Summary: This study revealed the conformational changes of polystyrene (PS) chains at the film surface after contacting with solid surfaces on a molecular scale. The differences between quartz surface and hydrophobic surface are explained in terms of the Coulomb interaction, providing insights into the adhesion process.
Article
Chemistry, Physical
Daisuke Kawaguchi, Kentaro Yamamoto, Tatsuki Abe, Naisheng Jiang, Tadanori Koga, Satoru Yamamoto, Keiji Tanaka
Summary: The study reported on the crystalline orientation of isotactic polypropylene in spin-coated films, revealing a change in crystalline orientation of cross-hatched lamellae with decreasing thickness.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
