Abstract
The temperature dependence of the binding constant KB for cyclodextrin (CD) and nitrophenol (NP) system is investigated using a previously proposed method. The method is based on the selective inclusion property of cyclodextrin (CD) and the selective permeability of the ultrafiltration membrane (UF/m). KB decreases with increasing temperature. Meanwhile, the activation energy of binding (ΔET) is calculated from the Arrhenius plot and it is a negative value. The absolute values of ΔET become large in the order of o-, m-, and p-NPs. These values approximately agree with those of other investigators who employed other methods. Furthermore, the forcible binding energy ΔEF is calculated from the pressure (Pd), where the rise ratio of rejection (η) begins deviating from the constant value which is measured at lower pressure. ΔEF agrees with ΔET. The ratio of ΔET to ΔEF is nearly constant at 7, and independent of pH and the reaction system.
