Uptake of Cycloalkanes and Bicyclic Aromatic Compounds by Ion-Exchange Resins from Aqueous Solutions

Abstract

The uptakes of cycloalkanes (C5 -C8) and bicyclic aromatic compounds (naphthalene, biphenyl, and azulene) by both strong acid cation (Dowex 50W-X4 and X8) and strong base anion (Dowex 1-X4 and X8) exchange resins have been studied in aqueous solutions at 25˚C; their distribution constants (K) have been determined. The relationship between the octanol-water partition coefficient and the resin affinity for solutes has been analyzed. The K values of three aromatic compounds were found to be much higher than expected from the octanol-water partition coefficients. This is probably due to the π interaction of aromatic rings with the resin matrix. Microscopic observations revealed that azulene molecules are uniformly distributed inside a resin particle.

Uptake of Benzene and Alkylbenzenes by Cation- and Anion-Exchange Resins from Aqueous Solutions

“…A comparison of the present results with those from our previous study 2 shows that the affinity of benzene to both cation 900 ANALYTICAL SCIENCES JUNE 2006, VOL. 22 and anion exchangers is about a half that of cyclohexane.…”

“…5 The logarithmic relationships between the K and Kow values are plotted by squares in Fig. 2, where, for the sake of comparison, our previous data on alkanes (C5-C9) and alcohols (C4-C7) 1 and cycloalkanes (C5-C8) 2 are illustrated by relatively small circles and our data on bicyclic aromatic compounds (naphthalene, biphenyl, and azulene) 2 by relatively small triangles. Some uptake characteristics can be seen from Table 1 and Fig.…”

Uptake of Iodine and Bromine by Ion-Exchange Resins in Aqueous Solution

“…All of the organic nonelectrolytes that we have so far studied have shown a direct proportional relationship between the amount of solute taken up by resins and the solute concentration in aqueous solutions. [1][2][3] This gives us an image of solvent extraction, the partition of a solute between the organic solvent and the aqueous phase; resin particles seem to be an organic solvent. In the present study, however, the uptake mechanism of the bromine-anion exchanger system appeared to be adsorption rather than partition.…”

“…[1][2][3] Iodine and bromine were of analytical grade, commercially available from Wako Pure Chemical Co., and were used as received.…”

“…cycloalkanes and bicyclic aromatic compounds, 2 as well as benzene and alkylbenzenes 3 by ion-exchange resins from aqueous solutions. We demonstrated that the uptake of these solutes is governed by partition, rather than adsorption.…”