Anion exchangers, hydrophobic synthesis

We have also shown how ion-exchange properties and hydrophobic character can be adjusted.90-91 The potential stimuli or chemical property behavior is dependent on the counterion incorporated during synthesis, as discussed previously. As illustrated in Figure 3.6, the chemical interaction properties (cation exchange, hydrophobic, and anion exchange) and the way they vary as a function of potential are markedly dependent on the counterion (Cl-, pTS", or DS") incorporated during synthesis. 

Another point of importance is that the oil phase should be water-immiscible, but not strongly hydrophobic it should be able to dissolve excess surfactants. The oil phase should be inert under the experimental conditions and have a boiling temperature less than its decomposition temperature to facilitate its removal without residue after the synthesis. Also, it should have a suitable azeotropic relation with water, again important for the removal of organics after the synthesis. Finally, the metal salt to be used should be such that its anions can be easily removed, e.g. by thermal decomposition or with the help of anion exchange resins. 

---