Article
Polymer Science
Shin-nosuke Nishimura, Kei Nishida, Tomoya Ueda, Shohei Shiomoto, Masaru Tanaka
Summary: Poly(N-isopropylacrylamide) (PNIPAM) is a commonly used thermoresponsive polymer that has been widely applied in biological applications. However, due to the presence of a hydrogen-bond donor, PNIPAM often induces blood clot formation, making alternatives to PNIPAM with aprotic polar functional groups necessary. In this study, acrylate polymers containing the aprotic polar functional group pyrrolidone ring were synthesized, and their lower critical solution temperatures (LCSTs) could be precisely controlled. These polymers demonstrated good blood compatibility and cell affinity, and interestingly, could activate macrophages without cytotoxicity when their hydrophobic/hydrophilic balance was altered.
Article
Environmental Sciences
Ye -Lim Han, Hye-Ran Kim, Hyun-Kyung Kim, Jae -Woo Park
Summary: A series of thermosensitive and magneto-responsive dendrimers were synthesized and their properties at different temperatures were studied. The results showed that PNIPAM-g-MCD could encapsulate and fix benzene molecules below the critical solution temperature, while it could disrupt oil-water emulsions above the critical solution temperature.
Article
Chemistry, Multidisciplinary
Mitsuhiro Matsumoto, Taka-Aki Asoh, Tatsuya Shoji, Yasuyuki Tsuboi
Summary: This study demonstrates liquid-liquid phase separation of a thermoresponsive polymer through near-infrared laser-induced coacervation and coil-to-globule phase transition. By focusing a laser beam, single polymer microdroplets can be formed and trapped at the focal point, allowing for selective analysis. The results indicate that PDEA undergoes dehydration and coacervation in addition to a coil-to-globule phase transition.
Article
Chemistry, Multidisciplinary
Hironori Ishihara, Reika Ikemoto, Misato Yamamoto, Yusuke Sanada, Keisuke Watanabe, Yukiteru Katsumoto
Summary: The relationship between dehydration of polymer chains and the nanodroplet formation through macroscopic liquid-liquid phase separation (LLPS) was investigated. It was found that PNiPAm chains have a narrower temperature range of dehydration compared to PNdEAm. The sharp dehydration of PNiPAm chains leads to its characteristic thermoresponsive behavior in water. For PNiPAm solutions with a high meso content, the dehydration of chains occurs before the macroscopic LLPS.
Article
Polymer Science
McKenzie L. Coughlin, Jerrick Edmund, Frank S. Bates, Timothy P. Lodge
Summary: Methylcellulose (MC), a water-soluble cellulose ether, exhibits thermoreversible gelation, which has multiple applications. Recent research has shown that MC gelation is caused by the formation of nanofibrils with a uniform diameter (approximately 15 nm) and that gelation can be suppressed by adding low-molecular-weight poly(ethylene glycol) along the backbone. In this study, we modify MC with thiol-terminated poly(N-isopropylacrylamide) (PNIPAm) using thiol-ene click chemistry and investigate its influence on aqueous MC solution properties. The results suggest that grafting PNIPAm increases the coil dimensions and the persistence length of MC, and it also increases the theta temperature, even though PNIPAm typically has a lower critical solution temperature. Fibril formation still occurs at high temperature for the grafted chains.
Article
Chemistry, Physical
Biaolan Liu, Xiaoshuang Yan, Zhihui Zhao, Jian Wang, Jiwen Feng
Summary: The solvation behaviors and intermolecular interactions of PDEA gel network in water/DMSO and water/acetone mixtures were investigated. Unlike PNIPAM gel, distinct phase transition behaviors were observed for PDEA gel, which are attributed to the different polymer-cosolvent interactions in water/acetone and water/DMSO systems.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Analytical
Qiurong Luo, Zhirong Zhong, Yunchao Zheng, Die Gao, Zhining Xia, Lujun Wang
Summary: The study polymerized poly(N-isopropylacrylamide) onto the surface of graphene quantum dots (GQDs) functionalized silica as packing materials, demonstrating a column with reversed-phase and hydrophilic interaction modes for separating target analytes with different Log P values. The Sil-GQDs-PNIPAAm stationary phase shows potential for improving the analysis range and performance of traditional phases.
Article
Chemistry, Physical
Alejandra Londono-Calderon, Wenjie Wang, Jack J. Lawrence, Wei Bu, David Vaknin, Tanya Prozorov
Summary: This study explores the dynamic response of aqueous solution containing pNIPAM-capped Au nanoparticles to NaCl introduction. The addition of NaCl induces liquid-liquid phase separation, leading to the formation of pNIPAM-filled globular assemblies at the air/water interface, which collapse to form hexagonal crystalline domains of varying sizes depending on NaCl concentration.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Polymer Science
Ya-Chen Chuang, Yu-Chia Chang, Meng-Tzu Tsai, Ting-Wei Yang, Meng-Tse Huang, Shao-Hua Wu, Chi Wang
Summary: The phase diagram of a polymer solution can determine its electrospinnability and transition temperatures. Low-temperature electrospinning can successfully produce uniform nanofibers, while electrospinning within a specific temperature range is feasible, but it becomes problematic at higher temperatures due to the enhanced gel elasticity.
Article
Polymer Science
Beomsu Park, Masatoshi Tosaka, Shigeru Yamago
Summary: Isotactic poly(N, N-diethyl acrylamide) (i-PDEAA) was synthesized by ytterbium triflate/H2O-catalyzed radical polymerization and its single crystals were successfully grown from solution. The lattice constants of Form-1 crystal were determined, while those of Form-2 crystal were only roughly estimated. The study provided insights into the crystallization of i-PDEAA and its crystal polymorphisms.
Article
Polymer Science
Bart-Jan Niebuur, Wiebke Lohstroh, Chia-Hsin Ko, Marie-Sousai Appavou, Alfons Schulte, Christine M. Papadakis
Summary: The water dynamics of concentrated PNIPAM solution in a water/methanol mixture were studied at different pressures, revealing that the binding strength between water and PNIPAM decreases gradually with increasing temperature under high pressure conditions. Raman spectroscopy also showed that methanol adsorbs to hydrophobic groups at atmospheric pressure but diminishes at high pressures.
Article
Engineering, Environmental
Momen S. A. Abdelaty
Summary: A series of three functional and thermo-pH terpolymers were fabricated using two monomers to optimize the phase separation temperature of poly (N-isopropylacrylamide). The synthesized terpolymers were characterized using various chemical methods and physical characterization techniques. The phase separation temperature and the relative influence of DMAEAm and VA on transition temperature T-c of the terpolymer solution were investigated through turbidity tests and micro-DSC analysis.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2021)
Article
Polymer Science
Migle Babelyte, Laura Peciulyte, Vesta Navikaite-Snipaitiene, Joana Bendoraitiene, Volodymyr Samaryk, Ramune Rutkaite
Summary: Thermoresponsive chitosan-graft-poly(N-isopropylacrylamide) copolymers with different compositions were synthesized. The chemical structure of the copolymers was confirmed and their lower critical solution temperature (LCST) behavior was assessed. Copolymers with a certain content of poly(N-isopropylacrylamide) side chains demonstrated LCST behavior and could potentially be used in drug delivery systems or tissue engineering.
Article
Chemistry, Multidisciplinary
Zhiqiang Jiang, Bai Xue, Xiaoping Mai, Changmei Wu, Lingjun Zeng, Lan Xie, Qiang Zheng
Summary: New methods for recycling fly ash were developed to reduce environmental pollution. Biodegradable hydrophobic poly (L-lactic acid)/fly ash composites were successfully fabricated for anti-icing applications. The addition of FA@KH570 improved the interface bonding strength between fly ash and poly (L-lactic acid), and increased the crystallinity of the composite material. The resulting PLLA/FA@KH570 composite exhibited excellent anti-icing properties with a significantly increased contact angle.
Review
Materials Science, Multidisciplinary
Lin Tang, Ling Wang, Xiao Yang, Yiyu Fen, Yu Li, Wei Feng
Summary: PNIPAM-based smart hydrogels are important smart materials with unique thermo-responsive properties and promising applications. This review summarizes the development, fundamental design, synthetic strategies, and potential applications of these materials in various fields.
PROGRESS IN MATERIALS SCIENCE
(2021)
Article
Polymer Science
Shogo Tachibana, Kei Hashimoto, Haruna Mizuno, Kazuhide Ueno, Masayoshi Watanabe
Summary: The effects of polymer structure on CO2 separation and mechanical properties of ion gel membranes composed of ionic liquids and sulfonated polyimides were investigated. It was found that polymers with multiblock structure exhibited higher IL uptake and CO2 permeability, while those with fluorinated non-ionic part showed improved mechanical properties without sacrificing CO2 permeability. These results suggest that polyimide sequence and non-ionic structure play important roles in the performance of the composite membranes.
Article
Nanoscience & Nanotechnology
Shinji Kondou, Yusuke Sakashita, Xiaoxiao Yang, Kei Hashimoto, Kaoru Dokko, Masayoshi Watanabe, Kazuhide Ueno
Summary: The study found that poly(LiSTFSA) exhibited the highest ionic conductivity in the lowest polar mixture at the highest salt concentration, attributed to a unique conduction phenomenon. This provides insights into a new design strategy for nonaqueous liquid electrolytes for LIBs.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Yu Chikaoka, Riko Ochi, Kenta Fujii, Takaaki Ariga, Masato Sakurai, Ayuna Matsumoto, Tsukasa Ueda, Etsuro Iwama, Katsuhiko Naoi
Summary: In this study, a dual-cation system based on dimethyl carbonate (DMC) was developed, showing higher ionic conductivity and a stable single-phase solution compared to single-cation systems. Raman measurements indicated that the dual-cation system consisted of one DMC molecule and two or three BF4- complexes. The dual-cation system exhibited higher power performance and Li+ conductivity in a capacitor.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Multidisciplinary Sciences
Yuji Kamiyama, Ryota Tamate, Takashi Hiroi, Sadaki Samitsu, Kenta Fujii, Takeshi Ueki
Summary: Highly stretchable and self-healing polymer gels were fabricated through physical entanglements of ultrahigh-molecular weight (UHMW) polymers. The gels exhibited high stretchability, high ionic conductivity, and recyclability, and also showed self-healing ability at room temperature without any external stimuli.
Article
Chemistry, Multidisciplinary
Jonathon Tanks, Takashi Hiroi, Kenji Tamura, Kimiyoshi Naito
Summary: In this study, symmetrical organic disulfides were tethered to the basal planes of synthetic mica by intercalation, confining photo-induced reactions to the interlayer. This approach allows for the functionalization of nanosheets to act as hosts for various photo-induced reactions, providing control and versatility for a wide range of applications.
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2023)
Article
Chemistry, Multidisciplinary
Akio Kamimura, Takuji Kawamoto, Kenta Fujii
Summary: Plastics are widely used materials in modern life, but the need for effective recycling is becoming increasingly recognized. This study describes the discovery of new methods for chemically recycling plastics using ionic liquids. The ionic liquids successfully depolymerized polyamides and unsaturated polyesters, and the separation of products was achieved by developing solubility-switchable ionic liquids. These findings demonstrate the potential of ionic liquids as effective solvents for plastic recycling.
Article
Chemistry, Physical
Masashi Ohira, Shintaro Nakagawa, Ryotaro Sampei, Takako Noritomi, Takamasa Sakai, Mitsuhiro Shibayama, Xiang Li
Summary: Polymer crystallization significantly alters the physical properties of polymeric materials. However, little research has been done on crystallization in polymer networks. This study investigated the crystallization behavior of poly(ethylene glycol) (PEG) networks made from well-defined branched precursors. The results showed that network formation had a smaller effect on crystallization compared to the bulky end-groups in uncrosslinked polymers. The primary parameter that influenced crystallization in the PEG networks was the molecular weight of the precursor PEG, or the chain length between junctions.
Article
Chemistry, Physical
Saki Sawayama, Riko Ochi, Tsubasa Kawaguchi, Yu Katayama, Masayuki Morita, Kenta Fujii
Summary: We present highly concentrated electrolytes prepared with a fluorinated acetate solvent, which allows for a favorable electrode reaction in Li-ion batteries. The electrolyte consisting of 2,2,2-trifluoroethyl acetate (TFEAc) solvent and 3.2 mol dm(-3) LiFSA salt demonstrated improved charge-discharge behavior on the graphite negative electrode compared to an analogous electrolyte. The lower activation energy (E-a) of the graphite electrode reaction in the concentrated LiFSA/TFEAc electrolyte contributes to its kinetically unique behavior.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Yu Chikaoka, Naomasa Nakata, Kenta Fujii, Saki Sawayama, Riko Ochi, Etsuro Iwama, Naohisa Okita, Yuta Harada, Yuki Orikasa, Wako Naoi, Katsuhiko Naoi
Summary: In this study, a dual-salt electrolyte system was developed for achieving high capacity and rapid charge-discharge in Mg2+ secondary batteries. The results showed that the use of the dual-salt system improved the Mg2+ insertion/extraction at the cathode/electrolyte interface and enhanced the electrochemical performance of nanoscale cathodes.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Polymer Science
Lester C. Geonzon, Kei Hashimoto, Tatsuro Oda, Shingo Matsukawa, Koichi Mayumi
Summary: This study investigated the viscoelastic properties and temperature-dependent hierarchical structure of carrageenan gels using various methods, and found that different gels exhibited different responses and structural characteristics.
Article
Polymer Science
Motoki Shibata, Yohei Nakanishi, Jun Abe, Hiroshi Arima-Osonoi, Hiroki Iwase, Mitsuhiro Shibayama, Ryuhei Motokawa, Takayuki Kumada, Shin-ichi Takata, Katsuhiro Yamamoto, Mikihito Takenaka, Tsukasa Miyazaki
Summary: Microplastic pollution is causing degradation of marine ecosystems. Decomposition of plastic using near critical or supercritical water is a promising method to remove microplastics. This study investigated the decomposition processes of polystyrene particles in deuterated water under near critical or supercritical conditions and observed the changes in material structure.
Article
Polymer Science
Di Jia, Yui Tsuji, Mitsuhiro Shibayama, Murugappan Muthukumar
Summary: When long polymers are trapped in multiple entropic traps created by hydrogels, they are frozen into a nondiffusive topologically frustrated dynamical state (TFDS). The center of mass diffusion coefficient is zero in the TFDS regime, but the segmental dynamics of the macromolecule is active. It is found that the polydispersity in the number of monomers in the entropic traps is caused by conformational fluctuations.
Article
Dentistry, Oral Surgery & Medicine
Chiaki Tsutsumi-Arai, Kazuhiro Akutsu-Suyama, Yoko Iwamiya, Chika Terada-Ito, Zenji Hiroi, Mitsuhiro Shibayama, Kazuhito Satomura
Summary: This study investigated the surface characteristics of a denture base coating containing hinokitiol and its effect on Candida albicans adhesion and growth. The results showed that the hinokitiol coating had lower CFU and higher stability compared to the control group, and exhibited improved surface characteristics.
CLINICAL ORAL INVESTIGATIONS
(2023)
Article
Chemistry, Physical
Kenzo Suzuki, Saki Sawayama, Yuna Deguchi, Ryansu Sai, Jihae Han, Kenta Fujii
Summary: This study reports the structural and electrochemical characteristics of lithium-ion battery electrolyte solutions using ethylene sulfite (ES) as a solvent. The results show that the structure of the Li-ion complex changes with increasing lithium salt concentration. The concentrated LiFSA/ES solutions exhibit high C-rate performance.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Namie Ikeda, Asumi Ishikawa, Kenta Fujii
Summary: In this study, a novel solid polymer electrolyte with exceptional mechanical toughness and high ionic conductivity was reported. The density of crosslinking points in the polymer was found to strongly affect the mechanical properties and ion conducting performance. It was also found that the salt content had a direct impact on the structure of Li-ion complexes in the polymer, which in turn influenced the ion conduction properties.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
