Folke Fredlund

On the properties of solid and liquid ion exchangers–VI Application of a simple model to some ion exchange reactions on dinonylnaphtalene sulfonic acid in different solvents and for different cations with heptane as solvent

Abstract A simple model assuming three kinds of micelles has been applied to the K + H + exchange on dimonylnaphtalene sulfonic acid (HDNNS) in the solvents: chloroform, carbon tetrachloride, nitrobenzene and isooctanol, to the Ca 2+ H + exchange in heptane, nitrobenzene and isooctanol. In heptane the following exchanges were also studied: Ag + H + , Cu 2+ H + , Ni 2+ , Fe 3+ H + and Al 3+ H + . Also the water uptake was studied for Ca 2+ H + and K + H + in nitrobenzene as solvent. The three parameters, found to fit each system are collected in Table 2. At present no simple rationalization of these constants seems possible.

Studies of water in organic solvents using NMR and partition techniques-II Di-isopropyl ether, dibutyl phthalate and chloroform

Abstract The chemical shift and the equilibrium concentration of water have been determined as a function of water activity at 25°C in the three solvents di-isopropyl ether, dibutyl phthalate and chloroform. Using the computer program LETAGROP various equilibrium models are tested (cf. Table 2). The models giving the best fit are given in Table 3. While a monomer-dimer equilibrium fit the data in di-isopropyl ether and dibutyl phthalate, chloroform is best fitted with a monomer-trimer equilibrium. With the aid of the chemical shifts evaluated and of a very simple model it is found that for the solvents nitrobenzene, dichloro-ethane, di-isopropyl ether, linear and/or cyclic polymers explain the chemical shifts equally well. In chloroform a cyclic trimer fits the data better than a linear trimer. The data for dibutyl phthalate indicate strong interactions between the water dimer and the two ester groups of the solvent molecule.