Journal of the Clay Science Society of Japan (in Japanese)
Online ISSN : 2186-3563
Print ISSN : 0470-6455
ISSN-L : 0470-6455
Volume 40, Issue 3
Displaying 1-7 of 7 articles from this issue
  • Hideo HASHIZUME
    2001 Volume 40 Issue 3 Pages 152-158
    Published: February 28, 2001
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    The contribution of clay minerals to the chemical evolution in the early eath was reviewed. The roles of the clay mineral in the chemical evolution have been studied since Bernal (1949) suggested that the clay mineral was one of important materials to the origin of life. Many reseachers showed that the clay mineral in the process of the chemical evolution adsorbed an organic compound, concentrated it and acted as a catalyst to synthesize an organic molecule from inorganic molecules and to polymerize the organic molecule. A new possible utility of clay minerals, for example a cell made of a clay mineral is introdced here.
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  • Hisanao USAMI, Hitoshi FUJIMATSU
    2001 Volume 40 Issue 3 Pages 159-165
    Published: February 28, 2001
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    Artificial molecular assemblies to modify photosynthesis have been a dreamy target for many scientists. Clay mineral can be a candidate for molecular assembly system to make effective photoelectrontransfer reaction-a basic process of the photpsynthesis. The remarkable characteristics of clay minerals for the photoelectrontransfer can be classified as follows; 1) molecular aggregation in an antiparallel fashion, 2) high polarity to stabilize polar intermediates in photoinduced charge separated state and 3) applicability to many kinds of molecules by adjusting the basal spacing. The layered crystalline structure of clays can also work as a backbone building block in multilayered supramolecular systems.
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  • Shogo SHIMAZU
    2001 Volume 40 Issue 3 Pages 166-172
    Published: February 28, 2001
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    Clay-supported metal complexes were prepared by various methods such as cation exchange, chemically anchored ligand, and interlayer-polymerized ligand methods. Multiple modification of smectites with metal complexes and various organic guests (tuning guests) can be applied to the preparation of catalysts for the molecular recognition reactions such as shape selective, chemoselective, regioselective, and asymmetric hydrogenations. Especially, chiral Rh-phosphine complexes intercalated in taeniorite with structural tuning guests exhibited notably high activity and high selectivity in the asymmetric hydrogenation of acetophenone due to the larger open space in their interlayer structure.
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  • Eiichi NARITA
    2001 Volume 40 Issue 3 Pages 173-178
    Published: February 28, 2001
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    Increasing attention has been focused on the interaction between organic compounds and layered double hydroxides (LDHs) from viewpoints of separation, recover and concentration of organic substances, removal of harmful substances, retention of useful components, synthesis of porous materials etc. Recently, the intercalation of the biomolecules in living systems such as amino acids, polypeptides, sugars and nucleic acids into LDHs was also attempted from viewpoint of earth chemistry in which LDHs were regarded as anionic clays. In this article, the studies on the intercalation of the biomolecules mentioned above into LDHs were carried out and summarized together with the results of the recent researches on the intercalation of amino acids and sugars. As the results, not only anion but zwitterion of amino acids and non-ionic molecule of sugars were intercalated into the interlayer of Zn-Al and Mg-Al LDHs with indicating the selectivity by the kind of side chain group in the case of amino acids and by the number and configuration of hydroxide group in the case of sugars. It was also found that these organic compounds were deintercalated by the ion exchange with carbonate ion in which the parents LDHs were regenerated.
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  • Kazumi MIYAHARA, Masami OHTSUBO, Katsuya NAKAISHI, Yasuhisa ADACHI
    2001 Volume 40 Issue 3 Pages 179-184
    Published: February 28, 2001
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    The settling rate of the interface between sodium montmorillonite sediment and supernatant liquid was measured under a condition of high ionic strength as a function of solid volume fraction. The results were analyzed using the method of Michaels and Bolger to elucidate the physical indexes of flocculated sediment such as the settling velocity (Qf), the representative diameter (df), and the increase ratio of effective volume fraction (α) of floc. The applicability of this method to sodium montmorillonite was confirmed bycomparing the Qf and df values obtained from this method with those from the direct measurement previously reported. The floc of sodium montmorillonite retains more water compared with that of kaolinite and other materials.
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  • W.I.Starin FERNANDO, Ryuji KITAGAWA, Mayumi JIGE
    2001 Volume 40 Issue 3 Pages 185-196
    Published: February 28, 2001
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    The climate conditions in Sri Lanaka are briefly divided into three zones (wet, dry and intermediate), based on the average annual rainfall. Three typical weathered charnokite outcropswere selected in each zone.
    Weathering products formed from charnockitic rock distributed in three different climate were investigated by means of X-ray diffraction, Differential thermal analysis (DTA), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) and X-ray fluorescence analysis.
    In wet zone, vermiculite and kaolin mineral accompanied with gibbsite and goethite were formed. Vermiculite, interstratified mineral of biotite and vermiculite, smectite, halloysite and kaolinite were occurred in the outcrop of dry zone. On the other hand, only kaolinite and halloysite were formed in the intermediate zone. According to these results, the sequences of the formation of clay minerals in each zone are as follows;
    Wet zone: vermiculite → kaolinite → gibbsite.
    Halloysite →
    Intermediate zone: halloysite → kaolinite.
    Dry zone: biotite/vermiculite → vermiculite
    Smectite → kaolinite
    Halloysite →
    Based on the chemical analysis, a clearly different alteration trend in the dry zone compared with the wet and intermediate zones is recognized. The Chemical Intensity of Alteration ofthe most weatheredparts of charnokitic rocks in the wet, intermediate and dry zones indicates 100, 98 and less than 70, respectively.
    According to these results, alteration pathways from fresh to weathered charnokaitic rocks are clearly different under each climate conditions.
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  • Motoharu KAWANO
    2001 Volume 40 Issue 3 Pages 197-211
    Published: February 28, 2001
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
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