Aluminium oxide cross-linked montmorillonites, which have 17-19A of basal spacings and 350m²/g-500m²/g of specific surface areas were obtained. The synthesis was controlled by using solutions prepared at OH/Al=2. 1. After intercalating montmorillonite in the solution contained A1₁₃O₄(OH)⁷⁺₂₄ at room temperature, the product was subjected to the aging in water at 100°C for 5hr. It could be seen that the two step synthetic processes were indispensable for constructing Al13 polymers into the interlamella of clay.
The product had catalytic properties as acidic molecular sieves. When an ethanol reacted with the catalyst synthesized by the present study, it was confirmed that the oily substances were produced. According to the results of GS/MS and ¹ H NMR measurements, the substances were composed of the aliphatic hydrocarbon having the molecular weight of above 300 and the networks of-(CH₂)_n-.

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Surface sediment samples collected from the Okhotsk Sea to the South China Sea along the east Asiatic continent were submitted to clay mineral investigation. Results have shown the distinguishable distribution patterns of clay minerals in the seas and the ocean. The Okhotsk Sea is characterized by the most widespread distribution of smectite. Low concentration of kaolinite is also verified. In the Japan Sea, illite is the most widespread clay mineral, and smectite concentration widely varies from location to location. Kaolinite concentration tends to increase more than that of the Okhotsk Sea. The Pacific sediments along the Japanese Islands are characterized by the high concentration of smectite in the northern part, and of chlorite off the Ku Peninsula and Shikoku. The shallow water sediments from the East China Sea are characterized by the predominance of illite. In the Philippine Sea, the high concentration of smectite is recognized. In the area of the entrance of the Gulf of Thailand to the South China Sea, the high concentration of kaolinite is observed. The results revealed that the distribution of clay minerals in the seas and the ocean along the east Asiatic continent is closely related to the geological and pedological characteristics on the bordering land areas.

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Theoretical X-ray powder patterns for (1) illite/air dried montmorillonite interstratification, and (2) illite/ethylene glycol treated montmorillonite one are presented. The mean number of layers and its standard deviation are fixed at N=10 and σ=2.0 respectively. Their basal spacings expected are collected in the table.

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The phosphate sorption product on the clay fraction of Kanuma pumice (KP clay) after air-drying was revealed to be a material close to noncrystalline aluminum phosphate by infrared absorption (IR) spectroscopy. The IR spectrum of phosphate sorbed, obtained by subtracting the diffuse reflectance IR spectrum of KP clay from that of the phosphated KP clay, was close to that of noncrystalline aluminum phosphate. During the phosphate sorption reaction on KP clay, the amount of Cl^-sorption and the concentration of dissolved Al at the initial pH of 4.0 decreased with phosphate sorption. The amount of silicon released, that of Na⁺ sorption and pH value increased with phosphate sorption. It was concluded that a part of KP clay, a short range order aluminosilicate, was converted to a material close to noncrystalline aluminum phosphate through phosphate sorption and release of silicon.

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The structural model of I/S was proposed. The I/S structures are divided into some groups by the number of I which exists between S and S. The structural types were defined as 0, 1, 2, 3, n. In the case of type 0, the structural model is defined in the range of 0-50 S% and the SS sequence is allowed in the nearest neighbour case of S and S. The structural model of type 1 is allowed in the range of 0-100 S% and the SIS sequence is recognized in the nearest neighbour case of S and S for 0-50 S%. The structural type 2 was defined in the range of 0-33 S% and the SIIS sequence exist in the nearest neighbour. The structural type 3 was defined in the range of 0-25 S% and the SIIIS sequence is recognized in the nearest neighbour case of S and S. Generally, the SI...IS sequence is recognized in the nearest neighbour case of S and S. The structural type of 1, 2, 3, ..., n correspond to Reichweite 0, 1, 2, 3, ...n, respectively. The theoretical X-ray diffraction profile of I/S proposed by I/S structural model were calculated. By using of positions three characteristic X-ray profiles, the diagram for identification of I/S structure was obtained. Using the diagram for natural specimen of I/S, the good results were obtained.

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Ammonium montmorillonite was hydrothermally synthesized from the amorphous gels at 240°C for 40-50 days. X-ray diffraction analysis, differential thermal analysis, infrared spectroscopy, chemical analysis and electron microscopy proved that ammonium montmorillonite was synthesized without other crystalline phases and its properties were identical to natural montmorillonite exchanged to ammonium type. However, formation region of this montmorillonite was fairly limitted and formation of non-swelling material like mica was observed in the samples treated at 240°C longer than 50 days and in the sample treated for 50 days at 250°C. Magnesium montmorillonite and another crystalline phase, i.e. zeolite-type compound with chemical formula of (NH₄)_1.1 (Mg_0.1Al_0.9) Si₂O₆·nH₂O, which was considered to be ammonium substituted analcime-type compound, was found in the sample treated for 150 days at 240°C.

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