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Volume 47 (2022)
- Issue 6 Pages 310-
- Issue 5 Pages 240-
- Issue 4 Pages 184-
- Issue 3 Pages 122-
- Issue 2 Pages 60-
- Issue 1 Pages 2-
Volume 47, Issue 2
Displaying 1-8 of 8 articles from this issue
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Special Topic : Two-dimensional materials creating membrane functions, from proton exchange to gas barrier
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Kazuto Hatakeyama2022 Volume 47 Issue 2 Pages 60-67
Published: 2022
Released on J-STAGE: April 14, 2022
JOURNAL RESTRICTED ACCESSFor sustainable development, there is a growing demand for proton exchange membranes, which play an important role in energy conversion and hydrogen production. Membranes constructed from nanosheets have high potential as proton exchange membranes due to their high mechanical strength, flexibility, and gas barrier properties. Herein, we demonstrate the proton–conducting properties of nanosheet membranes and their application as proton exchange membranes using graphene oxide as an example.View full abstractDownload PDF (963K) -
Kecheng Guan, Wanqin Jin, Hideto Matsuyama2022 Volume 47 Issue 2 Pages 68-75
Published: 2022
Released on J-STAGE: April 14, 2022
JOURNAL RESTRICTED ACCESSTwo–dimensional graphene–based nanosheets have attracted significant attention in a variety of fields owing to the distinct physical and chemical properties. The building block–like nanosheets have been manipulated and assembled as membranes showing intriguingly selective property for separations. Specifically, the nanometer and sub–nanometer scale confined space created by graphene materials exhibit distinct water transport behavior, which allows researchers to develop high performance water-selective membranes. Two main types of effective transport pathways have been created including graphene nanopores and nanochannels using different graphene materials and fabrication methods. In this review, the confined water transport in the nanopore and nanochannel is highlighted by discussing the recent advances in both theoretical and experimental perspectives.View full abstractDownload PDF (805K) -
Keizo Nakagawa2022 Volume 47 Issue 2 Pages 76-83
Published: 2022
Released on J-STAGE: April 14, 2022
JOURNAL RESTRICTED ACCESSOrganic solvent nanofiltration (OSN) is an energy–efficient alternative to distillation and evaporation for the separation of mixtures containing organic liquids. Laminar membranes using two–dimensional nanosheets as building blocks have great potential for OSN. In this review, recent developments of laminar membranes using graphene materials and nongraphene–based materials are introduced. The features, issues, and future prospects of the laminar membranes in organic solvent filtration are summarized.View full abstractDownload PDF (1079K) -
Masaya Miyagawa, Hiromitsu Takaba2022 Volume 47 Issue 2 Pages 84-91
Published: 2022
Released on J-STAGE: April 14, 2022
JOURNAL RESTRICTED ACCESSInterlayer of layered clay minerals is fascinating two–dimensional nanospace because small molecules are adsorbed by intercalation. However, it is technically difficult to investigate detail nanostructure and dynamics of the intercalation due to narrow gallery height, both of which are significant in ideal materials design at molecular level. In this point, molecular dynamics (MD) method is a promising tool. In this review, recent progress of the MD simulation of the layered clay minerals is summarized including the intercalation of some simple molecules such as H2O, CO2 and CH4 and also adsorption property of aromatic compounds of organoclay.View full abstractDownload PDF (1391K) -
Takatoshi Yamada, Shuichi Ogawa2022 Volume 47 Issue 2 Pages 92-97
Published: 2022
Released on J-STAGE: April 14, 2022
JOURNAL RESTRICTED ACCESSThere are several reports about gas barrier properties of graphene related materials including graphene, graphene oxide and reduced graphene oxide, however stabilities and gas permission mechanisms of graphene related materials have not yet been clarified. In our previous study, O2 molecules gas barrier properties of chemical vapor deposited (CVD) single layer graphene were characterized by using in–situ synchrotron radiation X-ray photoelectron spectroscopy (SR–XPS). A single layer graphene was deposited on Cu (111)/Al2O3 (0001) substrate by thermal CVD method. O2 molecules with kinetic energies between 0.07 and 1.77 eV were irradiated on graphene/Cu (111) samples and oxidizations of Cu surfaces were evaluated by SR–XPS. At low kinetic energies, Cu surfaces were not oxidized. While oxidizations on Cu surfaces were confirmed at high kinetic energies. Interestingly, graphene was not damaged after O2 molecules irradiations regardless of kinetic energies. Based on molecular dynamics-based simulation, it was found that O2 molecules were traveled though divacancy defects in graphene at the high irradiation energies. In case of the low irradiation energies, O2 molecules were bounced off the surface and floated away.View full abstractDownload PDF (792K) -
Takeo Ebina2022 Volume 47 Issue 2 Pages 98-104
Published: 2022
Released on J-STAGE: April 14, 2022
JOURNAL RESTRICTED ACCESSClay is silicate having plate–like crystal structure, and various clays are available as natural and synthetic products. Clay called smectite is unique in terms of its swelling property and has been used in various industrial applications. One of its uses is polymer clay composites. The added clay is highly dispersed in the polymer matrix at the nano level, thus controlling the properties of the composite. The properties of these composites vary greatly depending on the ratio of the polymer and the clay. When the ratio of clay is high, the composite bears the inherent characteristics of clay, these are, gas barrier property, heat resistance, flame retardancy, and so on. The films of composites containing clay as the main component and their applications are introduced.View full abstractDownload PDF (833K)
Special Contribution :
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Ryosuke Takagi2022 Volume 47 Issue 2 Pages 105-114
Published: 2022
Released on J-STAGE: April 14, 2022
JOURNAL RESTRICTED ACCESSI was requested to write an article about the history, current situation, future etc. related to my research field. My research topic is “Characterization of membrane charge, and modeling of membrane”. I have characterized the membrane charge by analyzing the membrane potential, and have investigated the effect of membrane charge on the ion flux through membrane. I don’t think any researcher would argue with that the membrane charge significantly affects the membrane performance. Even now, we spot the term “membrane potential” in some papers, especially, papers related with ion exchange membranes. However, at present, I guess that none of the researchers in the world studies on membrane potential except me. Thus, it is difficult to review the present situation and future in this filed. The progress of my research and memories during research life is reported reflecting on my research life instead. In this third article, I report my research life from around 2000 to present.View full abstractDownload PDF (1019K)
Products Spotlight :
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Katsuya Takuwa2022 Volume 47 Issue 2 Pages 115-118
Published: 2022
Released on J-STAGE: April 14, 2022
JOURNAL RESTRICTED ACCESSThe OxyMem MABR uses gas–permeable Poly–di–Methyl–Siloxane (PDMS, also known as silicone) hollow fiber membranes as both a medium to supply oxygen for aerobic treatment as well as a surface for the growth of a biological film. This biofilm, which receives its oxygen directly from the surface on which it’s growing, performs biological treatment for carbon and nitrogen removal, the two major pollutants in municipal wastewater. The OxyMem MABR modules can be operated either in a pure biofilm (OxyFILM) mode without MLSS (Mixed Liquor Suspended Solids) or in IFAS mode (Integrated Fixed film Activated Sludge) where there is MLSS (OxyFAS). In an OxyFILM mode the flow enters at the head of the MABR tank and passes through the membrane modules. The MABR can be operated in achieving oxygen transfer rates of up to 15 ～ 19 gO2/m2d and nitrification rates up to 2.3 gN/m2dView full abstractDownload PDF (780K)
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