start-ver=1.4 cd-journal=joma no-vol=234 cd-vols= no-issue= article-no= start-page=120015 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20250305 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Reversible chemical modifications of graphene oxide for enhanced viral capture and release in water en-subtitle= kn-subtitle= en-abstract= kn-abstract=Detecting low concentrations of viruses in sewage water is crucial for monitoring the spread of emerging viral diseases. However, current detection methods, which involve concentrating viruses using traditional materials such as gauze or cotton, have limitations in effectively accomplishing this task. This study demonstrates that graphene oxide (GO), a two-dimensional carbon material, possesses strong viral adsorption capabilities. However, it lacks efficiency for effective viral release. Therefore, we designed a series of new GO-based materials, which exhibited a viral adsorption similar to pristine GO, while significantly enhancing their release performance by attaching alkyl chains and hydrophilic functional groups. Among the synthesized materials, 1,8-aminooctanol grafted to GO (GO-NH2C8OH) has emerged as the most promising candidate, achieving a viral release rate higher than 50 %. This superior performance can be attributed to the synergistic effect of the alkyl chain and the terminal OH group, which enhances both its affinity for viruses and water dispersibility. Furthermore, we have successfully applied GO-NH2C8OH in a new protocol for concentrating viruses from sewage wastewater. This approach has demonstrated a 200-fold increase in virus concentration, allowing PCR detection of this type of pathogens present in wastewater below the detection limit by direct analysis, underscoring its significant potential for virus surveillance. en-copyright= kn-copyright= en-aut-name=Ferr?-PujolPilar en-aut-sei=Ferr?-Pujol en-aut-mei=Pilar kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ObataSeiji en-aut-sei=Obata en-aut-mei=Seiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=RayaJ?sus en-aut-sei=Raya en-aut-mei=J?sus kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=BiancoAlberto en-aut-sei=Bianco en-aut-mei=Alberto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KatayamaHiroyuki en-aut-sei=Katayama en-aut-mei=Hiroyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KatoTakashi en-aut-sei=Kato en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= affil-num=2 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= affil-num=3 en-affil=Institut de Chimie, UMR 7177 CNRS, Universit? de Strasbourg kn-affil= affil-num=4 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= affil-num=5 en-affil=Department of Urban Engineering, School of Engineering, The University of Tokyo kn-affil= affil-num=6 en-affil=Research Center for Water Environment Technology, School of Engineering, The University of Tokyo kn-affil= affil-num=7 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= en-keyword=Carbon nanomaterials kn-keyword=Carbon nanomaterials en-keyword=Functionalization kn-keyword=Functionalization en-keyword=Adsorption kn-keyword=Adsorption en-keyword=Desorption kn-keyword=Desorption en-keyword=Pathogens kn-keyword=Pathogens END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=e202404400 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20250107 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Graphene Oxide as a Self]Carbocatalyst to Facilitate the Ring]Opening Polymerization of Glycidol for Efficient Polyglycerol Grafting en-subtitle= kn-subtitle= en-abstract= kn-abstract=Grafting carbon-based nanomaterials (CNMs) with polyglycerol (PG) improves their application potentials in biomedicine and electronics. Although ggrafting fromh method offers advantages over ggrafting toh one in terms of operability and versatility, little is known about the reaction process of glycidol with the surface groups onto CNMs. By using graphene oxide (GO) as a multi-functional model material, we examined the reactivity of the surface groups on GO toward glycidol molecules via a set of model reactions. We reveal that carboxyl groups spontaneously react with the epoxide ring with no need of catalyst, while GO catalyzes the reactions of hydroxyl groups with the epoxide of glycidol. In addition, the hydroxyl group of glycidol can open the epoxide in the basal plane of GO. The subsequent polymerization of PG is supposed to propagate at the primary and/or the secondary hydroxyl groups, generating a ramified PG macromolecule with random branch-on-branch topology. In addition, ketones, benzyl esters and aromatic ethers are found not to react with glycidol even in the presence of GO, while the aldehydes are easily oxidized into carboxyl groups under ambient condition, behaving then as the carboxyl groups. Our findings pose the foundation for understanding the polymerization mechanism of PG on CNMs. en-copyright= kn-copyright= en-aut-name=ZouYajuan en-aut-sei=Zou en-aut-mei=Yajuan kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OhkuraKentaro en-aut-sei=Ohkura en-aut-mei=Kentaro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=Ortiz]AnayaIsrael en-aut-sei=Ortiz]Anaya en-aut-mei=Israel kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KimuraRyota en-aut-sei=Kimura en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=BiancoAlberto en-aut-sei=Bianco en-aut-mei=Alberto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= affil-num=6 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= en-keyword=Carbon nanomaterials kn-keyword=Carbon nanomaterials en-keyword=Epoxide ring-opening kn-keyword=Epoxide ring-opening en-keyword=Catalysis kn-keyword=Catalysis en-keyword=Polyglycerol functionalization kn-keyword=Polyglycerol functionalization END start-ver=1.4 cd-journal=joma no-vol=18 cd-vols= no-issue=49 article-no= start-page=33264 end-page=33275 dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20241122 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Mass Production of Graphene Oxide Beyond the Laboratory: Bridging the Gap Between Academic Research and Industry en-subtitle= kn-subtitle= en-abstract= kn-abstract=The mass production of graphene oxide (GO) has garnered significant attention in recent years due to its potential applications in various fields, from materials science to biomedicine. Graphene, known for its unique properties, such as high conductivity and mechanical strength, has been extensively studied. However, traditional production methods such as the exfoliation of graphite with scotch tape are not suitable for large-scale production. This has led to an increased focus on GO as a viable alternative to graphene production. Nonetheless, challenges, including the optimization of oxidation processes, the control of structural uniformity, and the reproducibility of production, have not been solved so far. This review critically examines GO production advancements by analyzing experimental and mechanistic studies to identify significant developments that enable high-yield and reproducible methods suitable for industrial-scale production. Special attention is given to oxidation techniques and postsynthesis purification and storage, with a focus on controlled oxidation to achieve homogeneous and single-layer GO. Through this lens, the review outlines the path forward for the industrialization of GO, aiming to bridge the gap between academic research and industrial production. en-copyright= kn-copyright= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= affil-num=1 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= en-keyword=Graphene oxide kn-keyword=Graphene oxide en-keyword=Graphite kn-keyword=Graphite en-keyword=Chemical oxidation kn-keyword=Chemical oxidation en-keyword=Electrochemical oxidation kn-keyword=Electrochemical oxidation en-keyword=Mass production kn-keyword=Mass production en-keyword=Purification kn-keyword=Purification en-keyword=Optimization kn-keyword=Optimization en-keyword=Industrialization kn-keyword=Industrialization en-keyword=Safety kn-keyword=Safety en-keyword=Stability kn-keyword=Stability END start-ver=1.4 cd-journal=joma no-vol=97 cd-vols= no-issue=11 article-no= start-page=uoae118 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20241111 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Refined surface area determination of graphene oxide using methylene blue as a probe molecule: a comparative approach en-subtitle= kn-subtitle= en-abstract= kn-abstract=In this research, we explored the effectiveness of the methylene blue adsorption method as an alternative approach for determining the specific surface area of graphene oxide. Initially, through a comparative analysis with reference activated carbon, we identified the limitations of utilizing N2 physisorption for specific surface area determination of graphene oxide. Our findings revealed that the standard pretreatment process (heating under vacuum) before N2 physisorption led to damage to the surface oxygen groups on graphene oxide, and the measured surface areas (43?m2/g) do not accurately represent the entire surface area. To optimize methylene blue coverage on graphene oxide, we conducted adsorption equilibrium experiments, focusing on controlling temperature and pH. The pH was significantly important in regulating the coverage of methylene blue. Under the optimized methylene blue adsorption conditions, the specific surface area of graphene oxide was 1,555?m2/g. Our assumptions regarding specific surface area calculations were supported by structural characterization of samples with varying methylene blue uptakes. The results confirmed a uniform coverage of methylene blue on graphene oxide by scanning electron microscopy and energy dispersive X-ray, X-ray diffraction, and atomic force microscopy. en-copyright= kn-copyright= en-aut-name=Ortiz-AnayaIsrael en-aut-sei=Ortiz-Anaya en-aut-mei=Israel kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Graduate School of Natural Sciences and Technology, Okayama University kn-affil= affil-num=2 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= en-keyword=graphene oxide kn-keyword=graphene oxide en-keyword=methylene blue kn-keyword=methylene blue en-keyword=specific surface area kn-keyword=specific surface area END start-ver=1.4 cd-journal=joma no-vol=125 cd-vols= no-issue=2 article-no= start-page=023104 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240708 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Enhanced thermal conductivity of fluids by percolating high-concentration few-layer graphene en-subtitle= kn-subtitle= en-abstract= kn-abstract=High-performance and small-sized heat exchangers have been demanded due to the miniaturization and higher output of electronic devices, lasers, and energy harvesting/storage systems. Graphene nanosheet suspension has attracted attention as a next-generation nanofluid because of its high thermal conductivity and low pressure drop, while being dispersed stably without any additives. Graphene-based nanofluids have been mostly investigated using graphene oxide, and there are a few studies on pure graphene because of the limitation in mass production and stabilization at high concentrations of graphene. In this study, we prepared a 10?wt. % high-concentration few-layer graphene suspension by pulverizing graphite particles. Scanning electron microscopy, atomic force microscopy, and Raman spectra confirmed the few-layer graphene is formed in the suspension. The thermal conductivity of the suspension increased with concentration and suddenly jumped at a specific concentration. Furthermore, a significant improvement in thermal conductivity of >40% compared to base liquid was confirmed at 10?wt. % graphene content. A similar trend was observed for electrical resistance; 10?wt. % graphene suspension showed 62% lower resistance than that of 1?wt. %. These results suggest the percolation of graphene in a liquid, which has not been observed for graphene-based materials in previous research. en-copyright= kn-copyright= en-aut-name=IshiiKeiko en-aut-sei=Ishii en-aut-mei=Keiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OgiyamaTakahiro en-aut-sei=Ogiyama en-aut-mei=Takahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FumotoKoji en-aut-sei=Fumoto en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=College of Science and Engineering, Chuo University kn-affil= affil-num=2 en-affil=College of Science and Engineering, Aoyama Gakuin University kn-affil= affil-num=3 en-affil=College of Science and Engineering, Aoyama Gakuin University kn-affil= affil-num=4 en-affil=Research Institute for Interdisciplinary Science, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=358 cd-vols= no-issue= article-no= start-page=142060 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=202406 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Size, polyglycerol grafting, and net surface charge of iron oxide nanoparticles determine their interaction and toxicity in Caenorhabditis elegans en-subtitle= kn-subtitle= en-abstract= kn-abstract=The widespread application of engineered nanoparticles (NPs) in environmental remediation has raised public concerns about their toxicity to aquatic organisms. Although appropriate surface modification can mitigate the ecotoxicity of NPs, the lack of polymer coating to inhibit toxicity completely and the insufficient knowledge about charge effect hinder the development of safe nanomaterials. Herein, we explored the potential of polyglycerol (PG) functionalization in alleviating the environmental risks of NPs. Iron oxide NPs (ION) of 20, 100, and 200 nm sizes (IONS, IONM and IONL, respectively) were grafted with PG to afford ION-PG. We examined the interaction of ION and ION-PG with Caenorhabditis elegans (C. elegans) and found that PG suppressed non-specific interaction of ION with C. elegans to reduce their accumulation and to inhibit their translocation. Particularly, IONS-PG was completely excluded from worms of all developmental stages. By covalently introducing sulfate, carboxyl and amino groups onto IONS-PG, we further demonstrated that positively charged IONS-PG-NH3+ induced high intestinal accumulation, cuticle adhesion and distal translocation, whereas the negatively charged IONS-PG-OSO3? and IONS-PG-COO? were excreted out. Consequently, no apparent deleterious effects on brood size and life span were observed in worms treated by IONS-PG and IONS-PG bearing negatively charged groups. This study presents new surface functionalization approaches for developing ecofriendly nanomaterials. en-copyright= kn-copyright= en-aut-name=ZouYajuan en-aut-sei=Zou en-aut-mei=Yajuan kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ShikanoYutaka en-aut-sei=Shikano en-aut-mei=Yutaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KomatsuNaoki en-aut-sei=Komatsu en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=Kage-NakadaiEriko en-aut-sei=Kage-Nakadai en-aut-mei=Eriko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=FujiwaraMasazumi en-aut-sei=Fujiwara en-aut-mei=Masazumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Institute of Systems and Information Engineering, University of Tsukuba kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Human and Environmental Studies, Kyoto University kn-affil= affil-num=5 en-affil=Department of Nutrition, Graduate School of Human Life and Ecology, Osaka Metropolitan University kn-affil= affil-num=6 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=iron oxide nanoparticles kn-keyword=iron oxide nanoparticles en-keyword=polyglycerol functionalization kn-keyword=polyglycerol functionalization en-keyword=C. elegans kn-keyword=C. elegans en-keyword=accumulation kn-keyword=accumulation en-keyword=distribution kn-keyword=distribution en-keyword=toxicity kn-keyword=toxicity END start-ver=1.4 cd-journal=joma no-vol=59 cd-vols= no-issue=17 article-no= start-page=2425 end-page=2428 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=2023 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Non-enzymatic detection of glucose levels in human blood plasma by a graphene oxide-modified organic transistor sensor en-subtitle= kn-subtitle= en-abstract= kn-abstract=We herein report an organic transistor functionalized with a phenylboronic acid derivative and graphene oxide for the quantification of plasma glucose levels, which has been achieved by the minimization of interferent effects derived from physical protein adsorption on the detection electrode. en-copyright= kn-copyright= en-aut-name=FanHaonan en-aut-sei=Fan en-aut-mei=Haonan kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SasakiYui en-aut-sei=Sasaki en-aut-mei=Yui kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ZhouQi en-aut-sei=Zhou en-aut-mei=Qi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TangWei en-aut-sei=Tang en-aut-mei=Wei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=MinamiTsuyoshi en-aut-sei=Minami en-aut-mei=Tsuyoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Institute of Industrial Science, The University of Tokyo kn-affil= affil-num=2 en-affil=Institute of Industrial Science, The University of Tokyo kn-affil= affil-num=3 en-affil=Institute of Industrial Science, The University of Tokyo kn-affil= affil-num=4 en-affil=Institute of Industrial Science, The University of Tokyo kn-affil= affil-num=5 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=6 en-affil=Institute of Industrial Science, The University of Tokyo kn-affil= END start-ver=1.4 cd-journal=joma no-vol=3 cd-vols= no-issue=5 article-no= start-page=394 end-page=405 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230911 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Highly Stretchable Stress-Strain Sensor from Elastomer Nanocomposites with Movable Cross-links and Ketjenblack en-subtitle= kn-subtitle= en-abstract= kn-abstract=Practical applications like very thin stress-strain sensors require high strength, stretchability, and conductivity, simultaneously. One of the approaches is improving the toughness of the stress-strain sensing materials. Polymeric materials with movable cross-links in which the polymer chain penetrates the cavity of cyclodextrin (CD) demonstrate enhanced strength and stretchability, simultaneously. We designed two approaches that utilize elastomer nanocomposites with movable cross-links and carbon filler (ketjenblack, KB). One approach is mixing SC (a single movable cross-network material), a linear polymer (poly(ethyl acrylate), PEA), and KB to obtain their composite. The electrical resistance increases proportionally with tensile strain, leading to the application of this composite as a stress- strain sensor. The responses of this material are stable for over 100 loading and unloading cycles. The other approach is a composite made with KB and a movable cross-network elastomer for knitting dissimilar polymers (KP), where movable cross-links connect the CD-modified polystyrene (PSCD) and PEA. The obtained composite acts as a highly sensitive stress-strain sensor that exhibits an exponential increase in resistance with increasing tensile strain due to the polymer dethreading from the CD rings. The designed preparations of highly repeatable or highly responsive stress-strain sensors with good mechanical properties can help broaden their application in electrical devices. en-copyright= kn-copyright= en-aut-name=IkuraRyohei en-aut-sei=Ikura en-aut-mei=Ryohei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KajimotoKota en-aut-sei=Kajimoto en-aut-mei=Kota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ParkJunsu en-aut-sei=Park en-aut-mei=Junsu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MurayamaShunsuke en-aut-sei=Murayama en-aut-mei=Shunsuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=FujiwaraYusei en-aut-sei=Fujiwara en-aut-mei=Yusei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=OsakiMotofumi en-aut-sei=Osaki en-aut-mei=Motofumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=SuzukiTomohiro en-aut-sei=Suzuki en-aut-mei=Tomohiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=ShirakawaHidenori en-aut-sei=Shirakawa en-aut-mei=Hidenori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=KitamuraYujiro en-aut-sei=Kitamura en-aut-mei=Yujiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=TakahashiHiroaki en-aut-sei=Takahashi en-aut-mei=Hiroaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=OhashiYasumasa en-aut-sei=Ohashi en-aut-mei=Yasumasa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=ObataSeiji en-aut-sei=Obata en-aut-mei=Seiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=HaradaAkira en-aut-sei=Harada en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=IkemotoYuka en-aut-sei=Ikemoto en-aut-mei=Yuka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= en-aut-name=UetsujiYasutomo en-aut-sei=Uetsuji en-aut-mei=Yasutomo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=16 ORCID= en-aut-name=MatsubaGo en-aut-sei=Matsuba en-aut-mei=Go kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=17 ORCID= en-aut-name=TakashimaYoshinori en-aut-sei=Takashima en-aut-mei=Yoshinori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=18 ORCID= affil-num=1 en-affil=Department of Macromolecular Science, Graduate School of Science and Forefront Research Center for Fundamental Sciences, Osaka University kn-affil= affil-num=2 en-affil=Department of Macromolecular Science, Graduate School of Science, Osaka University kn-affil= affil-num=3 en-affil=Department of Macromolecular Science, Graduate School of Science and Forefront Research Center for Fundamental Sciences, Osaka University kn-affil= affil-num=4 en-affil=Graduate School of Organic Materials Engineering, Yamagata University kn-affil= affil-num=5 en-affil=Department of Mechanical Engineering, Osaka Institute of Technology kn-affil= affil-num=6 en-affil=Department of Macromolecular Science, Graduate School of Science and Forefront Research Center for Fundamental Sciences, Osaka University kn-affil= affil-num=7 en-affil=Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. kn-affil= affil-num=8 en-affil=Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. kn-affil= affil-num=9 en-affil=Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. kn-affil= affil-num=10 en-affil=Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. kn-affil= affil-num=11 en-affil=Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. kn-affil= affil-num=12 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=13 en-affil=SANKEN (The Institute of Scientific and Industrial Research), Osaka University kn-affil= affil-num=14 en-affil=Japan Synchrotron Radiation Research Institute kn-affil= affil-num=15 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=16 en-affil=Department of Mechanical Engineering, Osaka Institute of Technology kn-affil= affil-num=17 en-affil=Graduate School of Organic Materials Engineering, Yamagata University kn-affil= affil-num=18 en-affil=Department of Macromolecular Science, Graduate School of Science and Forefront Research Center for Fundamental Sciences, Osaka University kn-affil= en-keyword=stress-strain sensor kn-keyword=stress-strain sensor en-keyword=carbon composite kn-keyword=carbon composite en-keyword=movable cross-link kn-keyword=movable cross-link en-keyword=supramolecular materials kn-keyword=supramolecular materials en-keyword=polymericmaterials kn-keyword=polymericmaterials en-keyword=tough materials kn-keyword=tough materials en-keyword=upcycling kn-keyword=upcycling END start-ver=1.4 cd-journal=joma no-vol=4 cd-vols= no-issue=10 article-no= start-page=2339 end-page=2345 dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=20220504 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Synergic effect of graphene oxide and boron nitride on the mechanical properties of polyimide composite films en-subtitle= kn-subtitle= en-abstract= kn-abstract=The addition of two-dimensional (2D) materials into polymers can improve their mechanical properties. In particular, graphene oxide (GO) and hexagonal boron nitride (h-BN) are expected to be potential nanoplatelet additives for polymers. Interactions between such nanoplatelets and polymers are effective in improving the above properties. However, no report has investigated the effect of using two types of nanoplatelets that have good interaction with polymers. In this study, we fabricated polyimide (PI) films that contain two types of nanoplatelets, amine-functionalized h-BN (BNNH2) and GO. We have elucidated that the critical ratio and the content of BNNH2 and GO within PI govern the films' mechanical properties. When the BNNH2/GO weight ratio was 52?:?1 and their content was 1 wt% in the PI film, the tensile modulus and tensile strength were increased by 155.2 MPa and 4.2 GPa compared with the pristine PI film. en-copyright= kn-copyright= en-aut-name=ChengYi Kai en-aut-sei=Cheng en-aut-mei=Yi Kai kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=Camp?onBeno?t Denis Louis en-aut-sei=Camp?on en-aut-mei=Beno?t Denis Louis kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ObataSeiji en-aut-sei=Obata en-aut-mei=Seiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=3 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=51 cd-vols= no-issue=5 article-no= start-page=1874 end-page=1878 dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=2022 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Grafting redox-active molecules on graphene oxide through a diamine linker: length optimization for electron transfer en-subtitle= kn-subtitle= en-abstract= kn-abstract=A redox-active molecule is grafted on graphene oxide (GO) via successive reactions. In the first step, GO is modified with diamine, which acts as a linker for the redox-active molecule. In the second step, the redox-active molecule is attached to the amino group of the linker by amide bond formation. Through these processes GO is partially reduced, enhancing its electrochemical properties. The structure of the functionalized GO is characterized by XPS, TGA, FTIR, and CV, and applied for electrodes in supercapacitors (SCs). The distance and direction of the redox-active molecule on the electrode affect the SC performance; ethylene diamine is the most promising linker to efficiently transfer electrons from the redox-active molecule to the electrode surface. en-copyright= kn-copyright= en-aut-name=KhanRizwan en-aut-sei=Khan en-aut-mei=Rizwan kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Graduate school of natural science and technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate school of natural science and technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=573 cd-vols= no-issue=30 article-no= start-page=151483 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=202201 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Uniform coating of magnesium oxide crystal with reduced graphene oxide achieves moisture barrier performance en-subtitle= kn-subtitle= en-abstract= kn-abstract=Magnesium oxide (MgO) has high thermal conductivity while keeping insulation; thus, MgO is attractive material as a filler for thermosetting or thermoplastic resins. However, MgO readily hydrates with water or moisture. Thus, the surface of MgO is coated with organic or inorganic substances.
We focused on graphene oxide (GO) as a surface coating agent. It has a 2-dimensional thin sheet structure, oxygen functional groups on the surface, and negative zeta-potential. Typically, GO has been used as a support material for metal nanoparticles. In this research, GO was coated on MgO micro-crystal surface to improve the surface character of MgO. The negatively charged GO and the positively charged MgO were combined with strong interaction. 0.5wt% GO coated MgO showed excellent moisture resistance compared to organic substances coating. Coating of MgO with GO or rGO is effective to overcome the weaknesses of MgO. Due to the hydrophilicity and high thermal conductivity of rGO, MgO/rGO composite can be a filler for high moisture resistance and thermal conductivity. en-copyright= kn-copyright= en-aut-name=SaitoAkinori en-aut-sei=Saito en-aut-mei=Akinori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ObataSeiji en-aut-sei=Obata en-aut-mei=Seiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Tateho chemical industries co. ltd kn-affil= affil-num=2 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=3 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= en-keyword=magnesium oxide kn-keyword=magnesium oxide en-keyword=graphene oxide kn-keyword=graphene oxide en-keyword=surface coating kn-keyword=surface coating en-keyword=moisture resistance kn-keyword=moisture resistance END start-ver=1.4 cd-journal=joma no-vol=3 cd-vols= no-issue=3 article-no= start-page=034008 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20210412 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Simulating the redox potentials of unexplored phenazine derivatives as electron mediators for biofuel cells en-subtitle= kn-subtitle= en-abstract= kn-abstract=In this research, we aimed to establish a guideline for designing electron mediators suitable for biofuel cells. A redox potential simulator was fabricated by combining density functional theory calculation and experiment, allowing us to select molecules with appropriate redox potentials efficiently. Previously, mediators have been developed depending on the trials and errors; thus, our strategy will speed up the development of biofuel cells with outstanding performances. en-copyright= kn-copyright= en-aut-name=NakagawaRyo en-aut-sei=Nakagawa en-aut-mei=Ryo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=redox potential kn-keyword=redox potential en-keyword=phenazine kn-keyword=phenazine en-keyword=mediator kn-keyword=mediator en-keyword=simulation kn-keyword=simulation en-keyword=DFT kn-keyword=DFT END start-ver=1.4 cd-journal=joma no-vol=2 cd-vols= no-issue=10 article-no= start-page=4417 end-page=4420 dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200824 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Bottom-up synthesis of nitrogen-doped nanocarbons by a combination of metal catalysis and a solution plasma process en-subtitle= kn-subtitle= en-abstract= kn-abstract=We aimed to develop the bottom-up synthesis of nanocarbons with specific functions from molecules without any leaving group, halogen atom and boronic acid, by employing a metal catalyst under solution plasma irradiation. Pyridine was used as a source of carbon. In the presence of a Pd catalyst, the plasma treatment enabled the synthesis of N-doped carbons with a pyridinic configuration, which worked as an active catalytic site for the oxygen reduction reaction. en-copyright= kn-copyright= en-aut-name=ZhouYang en-aut-sei=Zhou en-aut-mei=Yang kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=363 cd-vols= no-issue= article-no= start-page=137257 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20201210 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Sophisticated rGO synthesis and pre-lithiation unlocking full-cell lithium-ion battery high-rate performances en-subtitle= kn-subtitle= en-abstract= kn-abstract=For the application to portable devices and storage of renewable energies, high-performance lithium-ion batteries are in great demand. To this end, the development of high-performance electrode materials has been actively investigated. However, even if new materials exhibit high performance in a simple evaluation, namely half-cell tests, it is often impossible to obtain satisfactory performance with an actual battery (full cell). In this study, the structure of graphene analogs is modified in various ways to change crystallinity, disorder, oxygen content, electrical conductivity, and specific surface area. These graphene analogs are evaluated as negative electrodes for lithium-ion batteries, and we found reduced graphene oxide prepared by combination of chemical reduction and thermal treatment was the optimum. In addition, a full cell is fabricated by combining it with LiCoO2 modified with BaTiO3, which is applicable to high-speed charge?discharge cathode material developed in our previous research. In general, pre-lithiation is performed for the anode when assembling full cells. In this study, we optimized a "direct pre-lithiation" method in which the electrode and lithium foil were in direct contact before assembling a full cell, and created a lithium-ion battery with an output of 293 Wh kg?1 at 8,658 W kg?1. en-copyright= kn-copyright= en-aut-name=Camp?onBeno?t Denis Louis en-aut-sei=Camp?on en-aut-mei=Beno?t Denis Louis kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=YoshikawaYumi en-aut-sei=Yoshikawa en-aut-mei=Yumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TeranishiTakashi en-aut-sei=Teranishi en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Graphene kn-keyword=Graphene en-keyword=Lithium-ion battery kn-keyword=Lithium-ion battery en-keyword=Full-cell kn-keyword=Full-cell en-keyword=LiCoO2 kn-keyword=LiCoO2 en-keyword=High-rate kn-keyword=High-rate END start-ver=1.4 cd-journal=joma no-vol=12 cd-vols= no-issue=42 article-no= start-page=21780 end-page=21787 dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200928 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Iron nanoparticle templates for constructing 3D graphene framework with enhanced performance in sodium-ion batteries en-subtitle= kn-subtitle= en-abstract= kn-abstract=This study examines the synthesis and electrochemical performance of three-dimensional graphene for Li-ion batteries and Na-ion batteries. The in situ formation of iron hydroxide nanoparticles (Fe(OH)x NPs) of various weights on the surface of graphene oxide, followed by thermal treatment at elevated temperature and washing using hydrochloric acid, furnished 3D graphene. The characterization studies confirmed the prevention of graphene layer stacking by over 90% compared with thermal treatment without Fe(OH)x. The electrochemical performance of the 3D graphene was evaluated as a counter electrode for lithium metal and sodium metal in a half-cell configuration. This material showed good performances with a charging capacity of 507 mA h g?1 at 372 mA g?1 in Li-ion batteries and 252 mA h g?1 at 100 mA g?1 in Na-ion batteries, which is 1.4 and 1.9 times higher, respectively, than the graphene prepared without Fe(OH)x templates. en-copyright= kn-copyright= en-aut-name=Camp?onBeno?t D. L. en-aut-sei=Camp?on en-aut-mei=Beno?t D. L. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=WangChen en-aut-sei=Wang en-aut-mei=Chen kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=11 cd-vols= no-issue=23 article-no= start-page=5866 end-page=5873 dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200601 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Carbon-rich materials with three-dimensional ordering at the angstrom level en-subtitle= kn-subtitle= en-abstract= kn-abstract=Carbon-rich materials, which contain over 90% carbon, have been mainly synthesized by the carbonization of organic compounds. However, in many cases, their original molecular and ordered structures are decomposed by the carbonization process, which results in a failure to retain their original three-dimensional (3D) ordering at the angstrom level. Recently, we successfully produced carbon-rich materials that are able to retain their 3D ordering at the angstrom level even after the calcination of organic porous pillar[6]arene supramolecular assemblies and cyclic porphyrin dimer assemblies. Other new pathways to prepare carbon-rich materials with 3D ordering at the angstrom level are the controlled polymerization of designed monomers and redox reaction of graph. Electrocatalytic application using these materials is described. en-copyright= kn-copyright= en-aut-name=FaShixin en-aut-sei=Fa en-aut-mei=Shixin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=YamamotoMasanori en-aut-sei=Yamamoto en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NishiharaHirotomo en-aut-sei=Nishihara en-aut-mei=Hirotomo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SakamotoRyota en-aut-sei=Sakamoto en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KamiyaKazuhide en-aut-sei=Kamiya en-aut-mei=Kazuhide kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=OgoshiTomoki en-aut-sei=Ogoshi en-aut-mei=Tomoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University kn-affil= affil-num=2 en-affil=Institute of Multidisciplinary Research for Advanced Materials, Tohoku University kn-affil= affil-num=3 en-affil=Institute of Multidisciplinary Research for Advanced Materials, Tohoku University kn-affil= affil-num=4 en-affil=Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University kn-affil= affil-num=5 en-affil=Graduate School of Engineering Science, Osaka University kn-affil= affil-num=6 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=7 en-affil=Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=8 cd-vols= no-issue=2 article-no= start-page=238 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200219 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Structural Optimization of Alkylbenzenes as Graphene Dispersants en-subtitle= kn-subtitle= en-abstract= kn-abstract=Among the several methods of producing graphene, the liquid-phase exfoliation of graphite is attractive because of a simple and easy procedure, being expected for mass production. The dispersibility of graphene can be improved by adding a dispersant molecule that interacts with graphene, but the appropriate molecular design has not been proposed. In this study, we focused on aromatic compounds with alkyl chains as dispersing agents. We synthesized a series of alkyl aromatic compounds and evaluated their performance as a dispersant for graphene. The results suggest that the alkyl chain length and solubility in the solvent play a vital role in graphene dispersion. en-copyright= kn-copyright= en-aut-name=TakedaShimpei en-aut-sei=Takeda en-aut-mei=Shimpei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Graduate School of Natural Science & Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science & Technology, Okayama University kn-affil= en-keyword=graphene kn-keyword=graphene en-keyword=graphite kn-keyword=graphite en-keyword=dispersant kn-keyword=dispersant en-keyword=alkylbenzene kn-keyword=alkylbenzene en-keyword=liquid-phase exfoliation kn-keyword=liquid-phase exfoliation END start-ver=1.4 cd-journal=joma no-vol=104 cd-vols= no-issue= article-no= start-page=106475 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190731 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Bipolar anodic electrochemical exfoliation of graphite powders en-subtitle= kn-subtitle= en-abstract= kn-abstract=The electrochemical exfoliation of graphite has attracted considerable attention as a method for large-scale, rapid production of graphene and graphene oxide (GO). As exfoliation typically requires direct electrical contact, and is limited by the shape and/or size of the starting graphite, treatment of small graphite particles and powders, the typical form available commercially, is extremely difficult. In this study, GO nanosheets were successfully prepared from small graphite particles and powders by a bipolar electrochemical process. Graphite samples were placed between two platinum feeder electrodes, and a constant current was applied between the feeder electrodes using dilute sulfuric acid as the electrolyte. Optical microscopy, atomic force microscopy, X-ray diffractometry, Raman spectroscopy, and X-ray photoelectron spectroscopy were employed to examine the samples obtained after electrolysis. The results obtained from these analyses confirmed that anodic electrochemical exfoliation occurs in the graphite samples, and the exfoliated samples are basically highly crystalline GO nanosheets with a low degree of oxidation (C/O?=?3.6?5.3). This simple electrochemical method is extremely useful for preparing large amounts of graphene and GO from small particles of graphite. en-copyright= kn-copyright= en-aut-name=HashimotoHideki en-aut-sei=Hashimoto en-aut-mei=Hideki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MuramatsuYusuke en-aut-sei=Muramatsu en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=AsohHidetaka en-aut-sei=Asoh en-aut-mei=Hidetaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Department of Applied Chemistry, School of Advanced Engineering, Kogakuin University kn-affil= affil-num=2 en-affil=Department of Applied Chemistry, School of Advanced Engineering, Kogakuin University kn-affil= affil-num=3 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=4 en-affil=Department of Applied Chemistry, School of Advanced Engineering, Kogakuin University kn-affil= en-keyword=Graphite kn-keyword=Graphite en-keyword=Graphene kn-keyword=Graphene en-keyword=Graphene oxide kn-keyword=Graphene oxide en-keyword=Electrochemical exfoliation kn-keyword=Electrochemical exfoliation en-keyword=Anode kn-keyword=Anode en-keyword=Bipolar electrochemistry kn-keyword=Bipolar electrochemistry END start-ver=1.4 cd-journal=joma no-vol=29 cd-vols= no-issue=5 article-no= start-page=2150 end-page=2156 dt-received= dt-revised= dt-accepted= dt-pub-year=2017 dt-pub=20170302 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Real-Time, in Situ Monitoring of the Oxidation of Graphite: Lessons Learned en-subtitle= kn-subtitle= en-abstract= kn-abstract= Graphite oxide (GO) and its constituent layers (i.e., graphene oxide) display a broad range of functional groups and, as such, have attracted significant attention for use in numerous applications. GO is commonly prepared using the gHummers methodh or a variant thereof in which graphite is treated with KMnO4 and various additives in H2SO4. Despite its omnipresence, the underlying chemistry of such oxidation reactions is not well understood and typically affords results that are irreproducible and, in some cases, unsafe. To overcome these limitations, the oxidation of graphite under Hummers-type conditions was monitored over time using in situ X-ray diffraction and in situ X-ray absorption near edge structure analyses with synchrotron radiation. In conjunction with other atomic absorption spectroscopy, UV?vis spectroscopy and elemental analysis measurements, the underlying mechanism of the oxidation reaction was elucidated, and the reaction conditions were optimized. Ultimately, the methodology for reproducibly preparing GO on large scales using only graphite, H2SO4, and KMnO4 was developed and successfully adapted for use in continuous flow systems. en-copyright= kn-copyright= en-aut-name=MorimotoNaoki en-aut-sei=Morimoto en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SuzukiHideyuki en-aut-sei=Suzuki en-aut-mei=Hideyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakeuchiYasuo en-aut-sei=Takeuchi en-aut-mei=Yasuo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KawaguchiShogo en-aut-sei=Kawaguchi en-aut-mei=Shogo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KunisuMasahiro en-aut-sei=Kunisu en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=BielawskiChristopher W. en-aut-sei=Bielawski en-aut-mei=Christopher W. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Division of Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Division of Pharmaceutical Sciences, Okayama Universit kn-affil= affil-num=4 en-affil=Japan Synchrotron Radiation Research Institute (JASRI), SPring-8 kn-affil= affil-num=5 en-affil=Toray Research Center, Inc., Surface Science Laboratories kn-affil= affil-num=6 en-affil=Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS) kn-affil= affil-num=7 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= END