巻号一覧
37 巻 (1997 - 1998)
- 4 号 p. 137-
- 3 号 p. 87-
- 2 号 p. 37-
- 1 号 p. 1-
37 巻, 2 号
選択された号の論文の4件中1～4を表示しています
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村石 治人1997 年 37 巻 2 号 p. 37-46
発行日: 1997/10/31
公開日: 2011/09/20
ジャーナル フリーThe amount and the thermal behavior of interlayer water in original kenyaite (Na2Si22O41 (OH) 8 6H2O), and Li, Na, K, Rb, Cs ions-saturated kenyaite were mainly examined by means of X-ray diffraction, differential thermal analysis, and thermal gravimetric analysis.
The amount of interlayer water in the modifications were decreased with decreasing amount of alkali metal ions, and in the order Na+ > K+ >R13+> Cs+, which varied with the size of cation radius or the hydration energy for cations. In the case of Li and Cs modifications, however, the interlayer water content and the interlayer spacing showed relatively lower values than that of the other type modifications. Cs+ ion in the modification may be fixed in the eight-membered ring on the interlayer surface. Li+ion are presumed to be fixed by the adjacent=Si-OH group and=Si-O-on the surface.
The dehydration of interlayer water in Li, Na, K, Rb, and Cs ion modifications were carried out stepwise as 4, 4, 2, 3, and 3 steps, respectively. The water molecules released at the first step (dehydration at lowest temperature) for every modification may have formed hydration bond to the interlayer surface silanol group (Si-OH). The water molecules released at the last step (dehydration at highest temperature) may have been present in the state that has been strongly attracted to exchangeable cations, because a plot of the temperature of last dehydration step of them Td (Td: temperature of highest endothermic DTA peak) vs. the enthalpy of hydration ΔHh° for alkali metal ions gave linear relationship.抄録全体を表示PDF形式でダウンロード (1212K) -
門馬 恒視, 工藤 益男, 増子 徹1997 年 37 巻 2 号 p. 47-57
発行日: 1997/10/31
公開日: 2011/09/20
ジャーナル フリーRheological measurements for various natural or synthetic smectites/water suspensions were carried out based on smectite concentration. In all the smectite suspension, the transformation of flow curves obtained from a typical Newtonian to a distinct shear thinning type flow is observed with increasing smectite concentration. This indicates that the coagulated structure of the smectite particles in the system is formed at a certain critical concentration depending on the kind and composition of smectite materials. The critical concentrations are different among the dispersed smectite particles and are given as follows: the synthetic saponite, 1.2wt%; the synthetic hectorite, 1.0wt%; the synthetic stivensite, 1.5wt%; and the purified montmorillonite, 3.0wt%. In the case of synthetic saponite and hectorite dispersions at 2.0wt%, they show higher storage moduli in the order of 100 Pa than those of other smectite dispersions due to the formation of gel structure. This gel structure breaks easily by applying weak strain, and exhibits rapid structural recovery after releasing the strain. Purified montmorillonite particles form a similar gel structure in their suspension at more than 4wt% concentration, however its structural recovery rate at 4wt% is relatively slow as compared with the synthetic smectite suspension. Morphological examination of smectite at frozen state using a Cryo-SEM, clearly shows the presence of network structure formed by coagulated particles in all the smectite dispersions at 2.0wt%. The coagulated structural size of synthetic saponite dispersion was the largest among all other smectites and the network density is low. Synthetic stivensite on the other hand formed a network structure of considerably small size. Moreover, observation of montmorillonite suspension indicates that the resulting network structure is more loose than synthetic smectite and the existence of other independent particles. These differences in suspension structures explained well the rheological properties of smectite/water suspensions.抄録全体を表示PDF形式でダウンロード (3925K) -
Ag [2-(4-チアゾリル) ベンズイミダゾール] 2錯体と複数の第4級アンモニウムを坦持したモンモリロナイトの諸特性大橋 文彦, 大谷 朝男1997 年 37 巻 2 号 p. 58-65
発行日: 1997/10/31
公開日: 2011/09/20
ジャーナル フリーMontmorillonite intercalated with silver chelate of 2-(4-thiazolyl)-benzimidazole and quaternary ammonium cations (n-dodecyltrimethylammonium and hexadecylpyridinium) that has antibacterial and antifungal activities was prepared by cation exchange reaction (DHTAM). Theesulting material was subjected to antibacterial and antifungal activities examination and its structure was observed before and after heating up to 400s°C. Minimum inhibitory concentration tests showed that the sample has strong antibacterial and antifungal activities except with that of fungi of Aspergillus niger. Lost of antibacterial activities after heating at 250°Cccurred in only quaternary ammonium cations intercalated montmorillonite, but the DHTAM was stable up to 200°C and eventually decomposed at 400° resulting to the development of fine silver particles having significant antibacterial activities against bacteria of Escherichia coli and Staphylococcus aureus. The diameter of silver particles was 20-40nm, and did not change with increasing temperature. Three cations intercalated in montmorillonite showed simultaneously their characteristic individual activity, however, nosynergetic activity was observed in each intercalant. By using the present technique, it is possible to prepare more systematically an agent with desired antimicrobial and antifungal activities.抄録全体を表示PDF形式でダウンロード (3753K) -
1997 年 37 巻 2 号 p. e1
発行日: 1997年
公開日: 2011/09/20
ジャーナル フリーPDF形式でダウンロード (85K)
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