The synthesis of the CO₃/Mg-Fe layered double hydroxide (LDH) by a standard coprecipitation method has been investigated together with its antacid property. The LDH crystallinity of the solid product was influenced by the synthesized pH, Fe/(Mg+ Fe) mixed molar ratio and aging time. The solid products have the carbonated LDH structure with the basal spacing, d₀₀₃, of 7.8Å, in particular the well crystallized CO₃/Mg-Fe LDH was obtained at pH 10, Fe/(Mg+Fe)=0.25 and aging time 5 hours. From the results of XRD and TG-DTA, it was found that lattice constants a and c of the CO_3/Mg-Fe LDH obtained at the Fe/(Mg+Fe) mixed molar ratio of 0.17-0.25 range ageered with the Vegard rule, and the temperatures of elimination of interlayer water, dehydration of hydroxide basal layer and decarboxylation of guest anion were shifted by the amount of substituted Fe³⁺ ion for the LDH basal layer. In the durability experiments of the CO₃/Mg-Fe LDH as antacid, the time effecting antacid property for 65-95 min was observed in the CO₃/Mg-Fe LDH obtained at the Fe/(Mg+Fe) mixed molar ratio of 0.17-0.25 range. This feature of the CO₃/Mg-Fe LDH indicates that it can be used as for the substitute of the CO₃/Mg-Al LDH as antacid.

View full abstract

Adsorptions of Fe (II) ion (Fe²⁺) and Mn (II) ion (Mn²⁺) on the variable charge materials, silica and gibbsite which have surface functional groups, Si-OH and Al-OH, were investigated as a function of the solution pH, in order to grasp behaviors of the two ions in soils. Adsorption of Fe²⁺ on the both oxides occurred at lower solution pH range than that of Mn²⁺. Thus, it showed that Fe²⁺ had a stronger adsorptive affinity to the oxides than Mn²⁺. Most of adsorbed Fe²⁺ and Mn²⁺ on the oxides could not be desorbed by an ion-exchange reaction with MgCl₂. Adsorption-pH curves of the both ions were apparently different from that of Ca²⁺. The both ions were adsorbed on the oxides at higher pH range than Cu²⁺. These results implied that these two ions, Fe²⁺ and Mn²⁺ were specifically sorbed on the oxides, forming inner-sphere complexes.

View full abstract

Many landslides have been occurred in the Mikabu green rocks distributed in Shikoku Island. One of many factors of landslide occurrence is the formation of clay minerals by weathering and/or hydrothermal alteration process.
A lot of boring core specimens from the landslide areas where the Mikabu green rocks are distributed, Nuta/Youne and Kage landslide areas in Kohchi Prefecture, were collected. In this study, clay minerals formed in the boring cores were identified and their formation processes were discussed. As results, two different alteration zones were recognized by claymineral assemblage as follows;
Brownish zone: Chlorite, Chlorite/Smectite, Smectite, Vermiculite.
Greenish gray zone: Chlorite, Swelling chlorite, Chlorite/Smectite, Smectite.

View full abstract

C'est l'ancien feuille d'or à la tradition japonaise que est la plus mince feuille dans le monde. Dans ce dèrniere procèdéde la feuille d'or, on a été usé l'ancien papier japonaise qui contiens des argiles au nom de HAKUUCHIGAMI (Najiokami)
Nous avons maintenant examiné d'éffects d'argiles (kaolinite, smectite et ctr.) sur HAKUUCHIGAMI par les diffraction rayon-X, microscope d'éléctronique et ctr.
En ce qui concerne de la mallèabilité d'or, les argiles forment la face deglissement, alienent entre or et surface de papier, et refrigerent de l'énergie en frappant.
D'autre part, nous avons éxamine que les atoms d'or sont rearrangee à la face de (1, 0, 0, ) et nous avons supposeé le transparent de lumiere dans la feuille d'or par ce phenomene. La supposition de ce phenomene conduira le grand problem physique sur le cohérrence entre l'éléctron libere de metal et lumiere

View full abstract