Tanada S, Nakamura T, Kawasaki N, Kitayama S, Takebe Y
Faculty of Pharmaceutical Sciences, Kinki University, Kowakae, Higashi-Osaka, Osaka , 577, Japan
J Colloid Interface Sci. 1997 Feb 1;186(1):180-4. doi: 10.1006/jcis.1996.4627.
The adsorption isotherms of water, the differential heat of adsorption, and the entropy of adsorbed water were investigated to elucidate the structure of stability of cyclodextrins (CyD) and branched CyD's. The amount adsorbed on branched CyD's increased with increasing relative humidity. The steep rise in the amount adsorbed at higher relative humidities indicated that the structure of branched CyD's was affected by the water molecules at these higher relative humidities. The bonding force between alpha-CyD's and water molecules was stronger than that between their branched CyD's and water, while that between beta-CyD's and water was weaker than that between their branched CyD's and water. We have used activated carbons for the recovery of organic solvents. There are polar groups on the activated carbon surface. Therefore, the recovered organic solvents were degraded by these groups. However, such polar groups are not expected for the hydroxyl groups of the CyD's. The amounts of 1,1,1-trichloroethane, benzene, and toluene included in natural CyD's and their branched CyD's were measured. The amounts of organic solvents included in the CyD's depended upon the cavity radii and the glucosyl and maltosyl functional groups of the CyD's and the radii of the organic solvent molecules.
研究了水的吸附等温线、吸附微分热和吸附水的熵，以阐明环糊精（CyD）和支链环糊精的稳定性结构。支链环糊精上的吸附量随相对湿度的增加而增加。在较高相对湿度下吸附量的急剧上升表明，在这些较高相对湿度下，支链环糊精的结构受到水分子的影响。α-环糊精与水分子之间的结合力强于其支链环糊精与水之间的结合力，而β-环糊精与水之间的结合力弱于其支链环糊精与水之间的结合力。我们使用活性炭来回收有机溶剂。活性炭表面存在极性基团。因此，回收的有机溶剂会被这些基团降解。然而，环糊精的羟基预计不存在这样的极性基团。测定了天然环糊精及其支链环糊精中所含1,1,1-三氯乙烷、苯和甲苯的量。环糊精中所含有机溶剂的量取决于环糊精的腔半径、葡萄糖基和麦芽糖基官能团以及有机溶剂分子的半径。
